[{"content":"This page is under construction.\nDetails about who this guide is written for and what it aims to help you do will be added soon.\n","externalUrl":null,"permalink":"/en/developer-guide/about/","section":"Developer Guide","summary":"This page is under construction.\nDetails about who this guide is written for and what it aims to help you do will be added soon.\n","title":"About This Guide","type":"developer-guide"},{"content":"This page is under construction.\nDetails about who this guide is written for and what it aims to help you do will be added soon.\n","externalUrl":null,"permalink":"/en/organizer-guide/about/","section":"Organizer Guide","summary":"This page is under construction.\nDetails about who this guide is written for and what it aims to help you do will be added soon.\n","title":"About This Guide","type":"organizer-guide"},{"content":"This page is under construction.\nDetails about who this guide is written for and what it aims to help you do will be added soon.\n","externalUrl":null,"permalink":"/en/user-guide/about/","section":"User Guide","summary":"This page is under construction.\nDetails about who this guide is written for and what it aims to help you do will be added soon.\n","title":"About This Guide","type":"user-guide"},{"content":"1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan\nTsukuba Campus\nInstitute of Particle and Nuclear Studies\nWebsite YouTube X Facebook ","externalUrl":null,"permalink":"/en/institutions/kek/","section":"Participating Institutes","summary":"1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan\n","title":"High Energy Accelerator Research Organization (KEK)","type":"institutions"},{"content":"Associate Professor, Graduate School of Science, Osaka University\n2019 - present\n","externalUrl":null,"permalink":"/en/members/kazuki-ueno/","section":"Members","summary":"Associate Professor, Graduate School of Science, Osaka University\n","title":"Kazuki Ueno","type":"members"},{"content":"https://gitlab.com/osechi/osechi.gitlab.io\nThe official website for the compact cosmic ray detector OSECHI (planned).\n","externalUrl":null,"permalink":"/en/repos/osechi-gitlab-io/","section":"Repositories","summary":"https://gitlab.com/osechi/osechi.gitlab.io\nThe official website for the compact cosmic ray detector OSECHI (planned).\n","title":"osechi.gitlab.io","type":"repos"},{"content":"Cosmic rays are high-energy particles that rain down on Earth from outer space. When cosmic rays enter Earth\u0026rsquo;s atmosphere, they collide with atomic nuclei in the air and produce secondary particles. Of these, muons are the representative particles that reach the surface.\nTypes of Cosmic Rays # Primary Cosmic Rays # Particles traveling directly from space, observed above the atmosphere.\nProtons (hydrogen nuclei) — about 90% Helium nuclei (alpha particles) — about 9% Heavy element nuclei (carbon, iron, etc.) — about 1% Secondary Cosmic Rays # Particles produced when primary cosmic rays collide with atmospheric nuclei in the upper atmosphere (about 20 km altitude).\nMuons — the main particles that reach the surface Pions — parent particles of muons Gamma rays, electrons, positrons — electromagnetic component Journey to Earth # Cosmic rays travel through space at near-light speed and enter Earth\u0026rsquo;s atmosphere. Primary cosmic rays (mainly protons) collide with air and produce large numbers of secondary particles. Of these secondary particles, muons with their high penetrating power survive to reach the surface.\nHistory of Discovery # In 1912, Victor Hess discovered that radiation increased with altitude during balloon experiments. This revealed that some radiation comes from space, leading to the term \u0026ldquo;cosmic rays.\u0026rdquo;\nHess\u0026rsquo;s Balloon Experiment # It was believed that radiation originated from rocks and soil on the ground, but Hess confirmed that radiation levels increased even at 5,000m altitude, proving the existence of radiation of cosmic origin (Nobel Prize in Physics, 1936).\nReferences # \u0026ldquo;Victor F. Hess – Facts,\u0026rdquo; The Nobel Prize De Angelis, A., \u0026ldquo;Atmospheric ionization and cosmic rays: studies and measurements before 1912.\u0026rdquo; arXiv:1208.6527 ","externalUrl":null,"permalink":"/en/learn/cosmic-ray/","section":"Learning Guide","summary":"Cosmic rays are high-energy particles that rain down on Earth from outer space. When cosmic rays enter Earth’s atmosphere, they collide with atomic nuclei in the air and produce secondary particles. Of these, muons are the representative particles that reach the surface.\nTypes of Cosmic Rays # Primary Cosmic Rays # Particles traveling directly from space, observed above the atmosphere.\n","title":"What are Cosmic Rays?","type":"learn"},{"content":"Operate a measurement instrument with your own hands, and use it to measure cosmic rays yourself. We want to bring that experience to more people — that\u0026rsquo;s the future we\u0026rsquo;re working toward.\nMuon measurement is a topic covered even in university physics labs. Until now, though, it required expensive, large, high-voltage measurement equipment. This project develops OSECHI, a detector that\u0026rsquo;s compact and easy to handle while still delivering serious, research-grade measurement, and brings it into familiar settings — a school classroom, a local event, and more.\nBuild it, measure with it, understand it # OSECHI isn\u0026rsquo;t a \u0026ldquo;finished package\u0026rdquo; measurement device where you follow a fixed procedure and get your result. We\u0026rsquo;ve deliberately left room to get hands-on throughout — flashing the firmware, capturing and analyzing measurement data, operating and fine-tuning the device yourself. Filling in those gaps yourself is, we think, exactly what gives cosmic-ray measurement its hands-on feel.\nAlong the way, you\u0026rsquo;ll repeatedly run into moments where you have to think for yourself: how to take the data, how to read the results, how to fix things when they don\u0026rsquo;t work. That kind of trial and error doesn\u0026rsquo;t come from assembling a pre-made kit. It doesn\u0026rsquo;t come from reading about it or watching a demonstration at a science museum, either. Watching the \u0026ldquo;cosmic rays\u0026rdquo; you read about in a textbook get counted, live, on a device you operated yourself — that, we think, is the shortest path to making knowledge feel personal.\nThe society we want to build # Measuring cosmic rays with your own hands builds a foundation for scientific thinking that memorizing results alone never does. We want to grow the number of places — schools, communities — where that kind of experience is available, and in doing so, make science education something closer to everyday life.\nLooking ahead, we\u0026rsquo;d also like to grow this into a citizen-science observation network, where detectors scattered across the country pool their data and anyone can take part.\nAbout Us # This project began when members from various universities and research institutes across the country came together. Regardless of position or experience, we value respecting one another and working cooperatively. We aim to keep growing — both the people and the regions involved — while sharing the experience of measurement.\n","externalUrl":null,"permalink":"/en/about/vision/","section":"About OSECHI","summary":"Operate a measurement instrument with your own hands, and use it to measure cosmic rays yourself. We want to bring that experience to more people — that’s the future we’re working toward.\nMuon measurement is a topic covered even in university physics labs. Until now, though, it required expensive, large, high-voltage measurement equipment. This project develops OSECHI, a detector that’s compact and easy to handle while still delivering serious, research-grade measurement, and brings it into familiar settings — a school classroom, a local event, and more.\n","title":"Our Vision","type":"about"},{"content":"\u0026ldquo;OSECHI,\u0026rdquo; the name of our detector, traces back to a household item we stumbled on partway through building a prototype. Here\u0026rsquo;s the story of the OSECHI project so far.\nGetting Started # The OSECHI project began in June 2019, when a group of volunteers first came together. We initially named the project \u0026ldquo;Tan-Q,\u0026rdquo; and started planning and developing workshops built around a cosmic-ray detector.\nWhere the Name \u0026ldquo;OSECHI\u0026rdquo; Came From # While building a detector prototype for events at S-Bird in Iida, Nagano, and at Science Cafe Fukuoka, we needed a case to house it. We found an osechi box — a tiered box traditionally used for New Year\u0026rsquo;s food — at a 100-yen shop. It turned out to block light well enough for real use, so we adopted it as the detector\u0026rsquo;s enclosure as-is.\nFor a while we just called it the \u0026ldquo;osechi-box detector,\u0026rdquo; but it eventually got its official name: OSECHI, the name our detector carries today.\nThe Circle Grows # Starting with those early events at S-Bird and Science Cafe Fukuoka, events became a regular occurrence, and our circle of activity gradually grew. A teacher from Waseda University Honjo Senior High School joined the project, which led to the launch of \u0026ldquo;Fun-Q,\u0026rdquo; a spinoff project using OSECHI to survey ancient burial mounds. As membership grew, people also wanted a place to study together, giving rise to \u0026ldquo;Ben-Q,\u0026rdquo; an ongoing internal study group.\nRead more about our activities on the blog.\nKey Milestones # First meeting 2019-06-04 Ueno-san, Shoji-san, and Takahashi-san gather at KEK Project named \u0026#39;Tan-Q\u0026#39; 2019-07-08 Kyushu University joins 2019-09 Yoshioka-san joins Workshop at S-Bird, Iida, Nagano 2019-10-05 Demonstrates a detector prototype Science Cafe at BIZCOLI, Fukuoka City, Fukuoka 2019-12-13 Shows off a detector prototype Detector named \u0026#39;OSECHI\u0026#39; 2019-12-24 Finds an *osechi* box at a 100-yen shop and adopts it as the detector's enclosure Yamagata University joins 2020 Nakamori-san and colleagues join Osaka University joins 2022-04-01 Ueno-san moves from KEK to Osaka University, bringing the project along Measurement at Akiyama Koshinzuka Kofun 2022-04-25 Students from Waseda University Honjo Senior High School take measurements Nagoya University joins 2023-01-01 Takahashi-san moves from KEK to Nagoya University's KMI, bringing the project along Measurement at Akiyama Koshinzuka Kofun 2023-08-09 Takes measurements with an improved circuit board and DAQ Miyazaki University joins 2024 Takeda-san joins Toyama University joins 2025 Nakano-san and colleagues join Oita University joins 2025 Kobayashi-san joins NIT, Niihama College joins 2026 Yano-san joins ","externalUrl":null,"permalink":"/en/about/history/","section":"About OSECHI","summary":"“OSECHI,” the name of our detector, traces back to a household item we stumbled on partway through building a prototype. Here’s the story of the OSECHI project so far.\nGetting Started # The OSECHI project began in June 2019, when a group of volunteers first came together. We initially named the project “Tan-Q,” and started planning and developing workshops built around a cosmic-ray detector.\n","title":"History","type":"about"},{"content":"Here are some questions we\u0026rsquo;re often asked about the OSECHI project.\nHow do I join? # We currently use a referral-based system for joining. Please contact us, or reach out to a member at a nearby university or research institution.\nDo I need prior knowledge of cosmic rays to participate? # Yes — you don\u0026rsquo;t need any prior knowledge of cosmic rays, physics, or programming to participate. This is a hands-on project where you learn by doing. Come join us and have fun.\nIs there a cost to join? # No, there is no cost to join the community. However, costs such as building your own detector are your own responsibility.\nCan I participate online? # Yes, community interaction happens mainly online (via Discord) with members across the country. Workshop participation, however, is in person only.\nWhat age can participate? # There is no minimum age — anyone can participate as long as they have a working development environment. That said, since taking measurements at home or at school is largely self-directed, we mainly expect participants to be high-school age or older.\nCan I build my own detector? # Yes, the circuit design and component list are published on GitLab, so you can build your own detector from it. The circuit board can be manufactured through an online PCB service (such as JLCPCB). Electronic parts can also be purchased from online shops like Akizuki Denshi, Marutsu, or DigiKey. Some parts, such as the scintillator, can be a bit harder to source. Building one typically takes about two weeks to a month. See the developer guide for details.\nIs the detector\u0026rsquo;s electronics work dangerous? # No, manufacturing the circuit board itself is done through an online service, so it\u0026rsquo;s generally not dangerous. Attaching some additional parts by hand does involve a bit of electronics work — please work safely and at your own responsibility. If something seems broken or isn\u0026rsquo;t working right, feel free to ask for help on Discord.\nCan I borrow a fully built detector? # Yes, detectors built with public research funding are also sometimes available to borrow. Please contact us if you\u0026rsquo;re interested.\nIs measurement data made public? # Yes, data you collect is yours to use freely in your own research and presentations, including school projects and free-form research, with no restrictions. OSECHI also aims to support open science and citizen science, and we\u0026rsquo;d like to make everyone\u0026rsquo;s collected data available for others to use. If you plan to publish results in an academic paper, please talk to us first.\nCan anyone hold a workshop? # Yes, organizers are free to hold workshops at their own discretion. If you\u0026rsquo;d like to borrow a detector or have a researcher give a talk, please get in touch. We ask that a short report be shared afterward. See the organizer guide for details.\n","externalUrl":null,"permalink":"/en/about/faq/","section":"About OSECHI","summary":"Here are some questions we’re often asked about the OSECHI project.\nHow do I join? # We currently use a referral-based system for joining. Please contact us, or reach out to a member at a nearby university or research institution.\nDo I need prior knowledge of cosmic rays to participate? # Yes — you don’t need any prior knowledge of cosmic rays, physics, or programming to participate. This is a hands-on project where you learn by doing. Come join us and have fun.\n","title":"FAQ","type":"about"},{"content":" Contact Us # We\u0026rsquo;d love to hear from you! Please reach out with any questions or feedback about OSECHI.\nContact information will be available soon.\nFor more information, please visit our main website or check back soon for contact details.\n","externalUrl":null,"permalink":"/en/about/contact/","section":"About OSECHI","summary":"Contact Us # We’d love to hear from you! Please reach out with any questions or feedback about OSECHI.\nContact information will be available soon.\nFor more information, please visit our main website or check back soon for contact details.\n","title":"Contact","type":"about"},{"content":"744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan\nIto Campus\nFaculty of Arts and Science\nWebsite YouTube X Facebook Instagram LinkedIn ","externalUrl":null,"permalink":"/en/institutions/kyushu/","section":"Participating Institutes","summary":"744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan\n","title":"Kyushu University","type":"institutions"},{"content":"Professor, Faculty of Science, Yamagata University\n2020 - present\n","externalUrl":null,"permalink":"/en/members/takeshi-nakamori/","section":"Members","summary":"Professor, Faculty of Science, Yamagata University\n","title":"Takeshi Nakamori","type":"members"},{"content":"https://gitlab.com/osechi/tutorials\nBeginner-friendly tutorials on measurement and analysis using OSECHI.\n","externalUrl":null,"permalink":"/en/repos/tutorials/","section":"Repositories","summary":"https://gitlab.com/osechi/tutorials\nBeginner-friendly tutorials on measurement and analysis using OSECHI.\n","title":"tutorials","type":"repos"},{"content":" Properties of Muons # Muons (μ particles) are elementary particles belonging to the same family as electrons (leptons).\nProperty Value Mass ~207 times the electron mass (105.7 MeV/c²) Charge −1 (antimuon: +1) Spin 1/2 Mean lifetime ~2.2 microseconds (rest frame) Muons are far heavier than electrons and have high penetrating power, passing through most matter with ease.\nWhy Do They Reach the Ground? # Muons are created in the upper atmosphere (about 15 km altitude). With a rest-frame lifetime of ~2.2 μs, they should only travel about 660 m at light speed. Yet they reach the surface thanks to special relativity.\nRelativistic Effects # For muons moving at near-light speed, time passes more slowly (time dilation). From the ground\u0026rsquo;s perspective, the muon\u0026rsquo;s lifetime appears extended by tens of times. This allows them to travel over 15 km and reach the surface.\nInteraction with Earth\u0026rsquo;s Magnetic Field # East-West Effect # Earth\u0026rsquo;s magnetic field deflects the trajectories of muon parent particles (mainly protons). The number of particles arriving from the east and west becomes asymmetric — this is the east-west effect. It is also evidence that cosmic rays are predominantly positively charged.\nLatitude Effect # Earth\u0026rsquo;s magnetic field is stronger near the equator, deflecting low-energy cosmic rays. As a result, muon intensity is weaker near the equator and stronger near the poles.\n","externalUrl":null,"permalink":"/en/learn/muon/","section":"Learning Guide","summary":"Properties of Muons # Muons (μ particles) are elementary particles belonging to the same family as electrons (leptons).\nProperty Value Mass ~207 times the electron mass (105.7 MeV/c²) Charge −1 (antimuon: +1) Spin 1/2 Mean lifetime ~2.2 microseconds (rest frame) Muons are far heavier than electrons and have high penetrating power, passing through most matter with ease.\nWhy Do They Reach the Ground? # Muons are created in the upper atmosphere (about 15 km altitude). With a rest-frame lifetime of ~2.2 μs, they should only travel about 660 m at light speed. Yet they reach the surface thanks to special relativity.\n","title":"What are Muons?","type":"learn"},{"content":"Everything that goes into developing OSECHI is published in the OSECHI group on GitLab.\n","externalUrl":null,"permalink":"/en/repos/","section":"Repositories","summary":"Everything that goes into developing OSECHI is published in the OSECHI group on GitLab.\n","title":"Repositories","type":"repos"},{"content":"Datasets used in OSECHI papers are available from this page.\nComing soon.\n","externalUrl":null,"permalink":"/en/datasets/","section":"OSECHI","summary":"Datasets used in OSECHI papers are available from this page.\nComing soon.\n","title":"Datasets","type":"page"},{"content":"The amount of cosmic rays reaching Earth isn\u0026rsquo;t constant — it changes over time. One major reason is the activity of the Sun.\nThe Solar Wind Shields Galactic Cosmic Rays # The Sun constantly emits the solar wind, a stream of charged particles (protons, electrons, and others) that carries magnetic field throughout the solar system. Cosmic rays arriving from outside the galaxy (galactic cosmic rays) are partly deflected by this field, making it harder for them to reach the inner solar system.\nThe 11-Year Solar Cycle # Solar activity rises and falls in an roughly 11-year cycle, tracked by the number of sunspots (the solar cycle). During periods of high solar activity — when the solar wind is strong — fewer galactic cosmic rays reach Earth. Conversely, cosmic ray levels tend to rise during quiet periods of solar activity.\nForbush Decreases # A Forbush decrease is a sudden drop in the cosmic rays reaching Earth, lasting several days, triggered by a solar flare or coronal mass ejection (CME). A large eruption on the Sun\u0026rsquo;s surface releases plasma and a strong magnetic field into interplanetary space; as this passes by Earth, it temporarily shields the planet from galactic cosmic rays.\nThe largest Forbush decreases on record have reduced cosmic ray intensity by several tens of percent.\nConnecting to Everyday Cosmic Ray Observation # Running a ground-based detector like OSECHI over an extended period can reveal the gradual variation tied to the solar cycle, as well as the temporary dip that follows a major solar flare. In the field of space weather, cosmic ray data like this serves as one of the tools used to monitor solar activity.\nReferences # Potgieter, M. S., \u0026ldquo;Solar Modulation of Cosmic Rays,\u0026rdquo; Living Reviews in Solar Physics (2013). arXiv:1306.4421 ","externalUrl":null,"permalink":"/en/learn/solar-activity/","section":"Learning Guide","summary":"The amount of cosmic rays reaching Earth isn’t constant — it changes over time. One major reason is the activity of the Sun.\nThe Solar Wind Shields Galactic Cosmic Rays # The Sun constantly emits the solar wind, a stream of charged particles (protons, electrons, and others) that carries magnetic field throughout the solar system. Cosmic rays arriving from outside the galaxy (galactic cosmic rays) are partly deflected by this field, making it harder for them to reach the inner solar system.\n","title":"How Does Solar Activity Affect Cosmic Rays?","type":"learn"},{"content":"https://gitlab.com/osechi/kurikintons\nArduino-compatible firmware for OSECHI\u0026rsquo;s microcontroller (ESP32-WROOM-32E).\n","externalUrl":null,"permalink":"/en/repos/kurikintons/","section":"Repositories","summary":"https://gitlab.com/osechi/kurikintons\nArduino-compatible firmware for OSECHI’s microcontroller (ESP32-WROOM-32E).\n","title":"kurikintons","type":"repos"},{"content":"Technical Specialist, Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)\n2019 - present\n","externalUrl":null,"permalink":"/en/members/masayoshi-shoji/","section":"Members","summary":"Technical Specialist, Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)\n","title":"Masayoshi Shoji","type":"members"},{"content":"1-1 Gakuen Kibanadai-nishi, Miyazaki-shi, Miyazaki 889-2192, Japan\nKibanadai Campus\nWebsite YouTube X Facebook Instagram LinkedIn ","externalUrl":null,"permalink":"/en/institutions/miyazaki/","section":"Participating Institutes","summary":"1-1 Gakuen Kibanadai-nishi, Miyazaki-shi, Miyazaki 889-2192, Japan\n","title":"University of Miyazaki","type":"institutions"},{"content":"A scintillator is a material that emits visible or ultraviolet light when radiation — a charged particle or gamma ray — passes through it. This light emission is called scintillation.\nWhy It Glows # When a charged particle passes through a scintillator, it temporarily excites the atoms it passes near, bumping electrons into a higher energy state. As the electrons return to their original (ground) state, the energy difference is released as light. Charged particles like muons continuously trigger this emission as they travel through matter.\nTypes of Scintillators # Inorganic Scintillators # Crystals such as sodium iodide (NaI). They produce a lot of light and offer excellent energy resolution, but are hard to shape and expensive. Used in medical PET scans and high-precision gamma-ray measurements.\nOrganic (Plastic) Scintillators # Plastic mixed with a luminescent compound. Easy to shape, inexpensive, and durable. They produce less light than inorganic scintillators but respond faster, making them well suited to detecting charged particles like cosmic rays. OSECHI uses a plastic scintillator.\nCommercial plastic scintillators are still relatively expensive, so the OSECHI project is also developing a way to 3D-print scintillators at low cost. It\u0026rsquo;s one of several efforts aimed at making the detector more accessible.\nRole in Cosmic Ray Detection # When a muon passes through the scintillator, it produces a brief, faint flash of light. A photodetector converts this light into an electrical signal, recording exactly when and where the muon passed through. Adjusting the scintillator\u0026rsquo;s thickness and shape can tune the detector\u0026rsquo;s efficiency and directional resolution.\n","externalUrl":null,"permalink":"/en/learn/scintillator/","section":"Learning Guide","summary":"A scintillator is a material that emits visible or ultraviolet light when radiation — a charged particle or gamma ray — passes through it. This light emission is called scintillation.\nWhy It Glows # When a charged particle passes through a scintillator, it temporarily excites the atoms it passes near, bumping electrons into a higher energy state. As the electrons return to their original (ground) state, the energy difference is released as light. Charged particles like muons continuously trigger this emission as they travel through matter.\n","title":"What is a Scintillator?","type":"learn"},{"content":"https://gitlab.com/osechi/comochi_combu\nAn archive of OSECHI\u0026rsquo;s PCB design files.\n","externalUrl":null,"permalink":"/en/repos/comochi_combu/","section":"Repositories","summary":"https://gitlab.com/osechi/comochi_combu\nAn archive of OSECHI’s PCB design files.\n","title":"comochi_combu","type":"repos"},{"content":"Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan\nHigashiyama Campus\nKobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI)\nWebsite YouTube X Facebook LinkedIn ","externalUrl":null,"permalink":"/en/institutions/nagoya/","section":"Participating Institutes","summary":"Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan\n","title":"Nagoya University","type":"institutions"},{"content":"Designated Assistant Professor, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya University\n2019 - present\n","externalUrl":null,"permalink":"/en/members/shota-takahashi/","section":"Members","summary":"Designated Assistant Professor, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya University\n","title":"Shota Takahashi","type":"members"},{"content":"The light emitted by a scintillator is extremely faint — far too dim to see with the naked eye. A photodetector amplifies this faint light into a measurable electrical signal.\nTypes of Photodetectors # There are two broad approaches to converting and amplifying light into an electrical signal: vacuum-tube based and semiconductor based.\nPhotomultiplier Tubes (PMTs) # A Photo Multiplier Tube (PMT) is a vacuum tube that converts and amplifies light into an electrical signal.\nIncoming light knocks an electron (a photoelectron) loose from a photocathode (the photoelectric effect) That electron strikes a series of electrodes (dynodes), each collision releasing more electrons in a cascade The result is a current amplified by a factor of millions PMTs are highly sensitive and well established, but need high voltage (hundreds to thousands of volts) and are bulky and fragile.\nSemiconductor Photodetectors (SiPM/MPPC) # A SiPM (Silicon Photomultiplier) achieves the same single-photon sensitivity as a PMT using semiconductor technology instead. It consists of a large array of tiny photodiodes wired in parallel; only the cells struck by light respond, and their combined output gives the signal strength.\nHamamatsu Photonics\u0026rsquo; MPPC (Multi-Pixel Photon Counter) is a well-known type of SiPM. Being compact, low-voltage, and highly sensitive makes it easy to use in educational detectors.\nComparing PMT and SiPM/MPPC # PMT SiPM/MPPC Drive voltage Hundreds to thousands of volts Tens of volts Size Large Compact (a few mm across) Durability Fragile Rugged Cost Relatively expensive Relatively affordable In recent years, compact detectors have increasingly moved from PMTs to SiPM/MPPCs.\nRole in Cosmic Ray Detection # Converting the scintillator\u0026rsquo;s faint light into an electrical signal is what makes it possible to record a muon\u0026rsquo;s passage as numerical data. The signal\u0026rsquo;s strength (pulse height) also gives a rough measure of the energy the particle deposited in the scintillator. OSECHI uses a Hamamatsu Photonics MPPC as its photodetector.\nPulse Height and Energy # The longer the distance a particle travels through the scintillator, and the more energy it loses in the material, the more light is produced. Examining the signal\u0026rsquo;s pulse height therefore offers a clue to the type and energy of the particle that passed through.\n","externalUrl":null,"permalink":"/en/learn/photodetector/","section":"Learning Guide","summary":"The light emitted by a scintillator is extremely faint — far too dim to see with the naked eye. A photodetector amplifies this faint light into a measurable electrical signal.\nTypes of Photodetectors # There are two broad approaches to converting and amplifying light into an electrical signal: vacuum-tube based and semiconductor based.\nPhotomultiplier Tubes (PMTs) # A Photo Multiplier Tube (PMT) is a vacuum tube that converts and amplifies light into an electrical signal.\n","title":"What is a Photodetector?","type":"learn"},{"content":" Introduction # These guidelines summarize the basic mindset and a few requests for anyone taking part in activities using OSECHI. They are not meant to be enforced as strict rules — please use them as a reference when you\u0026rsquo;re unsure how to proceed with a specific activity.\n1. Purpose and Values # The OSECHI community aims to advance education and science outreach through the development and use of the compact cosmic ray detector OSECHI. We value an environment where anyone can participate regardless of their position — researchers and outreach staff at universities and research institutes, teachers, students, and others.\nWhen taking part in activities, please be mindful of safety, respect one another, and work together cooperatively.\n2. Community Roles # The OSECHI community has a few roles, depending on the scope of activity and responsibility involved.\nCore members — Lead the launch and operation of the OSECHI project and help decide its direction. They play a central role in decisions that affect the whole community and in coordinating with outside parties. Development team — Support the technical foundation of OSECHI, including detector design and software development. They mainly handle the practical work of development and improvement. User group — Carry out measurements, educational activities, and workshops using OSECHI. Through their hands-on use and feedback, they play an important role in growing and developing the community. These roles can overlap depending on the activity.\n3. Communication and Conduct # When taking part in the OSECHI community, please value open and friendly communication.\nBe respectful in your communication, regardless of position or experience Welcome questions and requests for advice from newcomers, and help keep the environment safe to participate in Please refrain from behavior that others may find offensive or aggressive If you\u0026rsquo;re unsure about something, feel free to ask Information is mainly shared through online tools such as Discord. When sharing photos or videos, please get permission from the people shown. Please take the same care when posting outside the community as well.\n4. How to Join and Get Involved # Referral-based — You can join through an introduction from an existing member Cost — There is no cost to join the community. That said, equipment and development costs are self-funded How to get involved — You\u0026rsquo;re free to participate online or offline To keep a safe and comfortable environment for everyone, we currently use a referral-based system for joining. At the same time, we want to remain a community that anyone can join.\nWe welcome many forms of participation — running workshops, creating teaching materials, sharing development or improvement ideas, and spreading the word about our activities. We also hope that using OSECHI in educational settings will spark new kinds of learning and activity.\nStarting small is fine. We\u0026rsquo;d love for you to value getting involved simply because you want to try something.\n5. Safety and Responsibility # Building a detector is done at your own risk — please work safely Take great care with tasks that involve risk, such as high voltage or soldering Take appropriate safety precautions suited to the activity, such as at workshops For any trouble that arises during an activity, we assume that each party involved is responsible for handling it themselves.\n6. Lending and Borrowing Equipment # Lending or borrowing a detector you built yourself should be done based on mutual agreement and responsibility between the parties involved. We recommend confirming in advance how damage or loss will be handled.\nDetectors built with public funding, such as government research grants, are managed by the lead institution and the core members. Lending of this equipment will follow management rules to be defined in the future, and may involve a loan agreement or similar documentation as needed.\n7. Hosting Workshops # Workshops using OSECHI can be freely organized at the organizer\u0026rsquo;s discretion. That said, any trouble arising during a workshop should be handled primarily by the organizer.\nAfter the workshop, please share a short report (with photos or comments, for example) as an example of community activity. When using photos or videos for this, please get permission from the people shown — especially when participants are included, please take care to explain things in advance.\n8. Publishing Results and Papers # When presenting at an academic conference or publishing a paper, please consult with the core members in advance and follow appropriate authorship practices based on actual contributions. For OSECHI-related work, we generally ask that you acknowledge the project and related activities. Beyond that, if someone made a clear contribution to the work, please include the development group as a whole, or individual members, as authors.\nWhen sharing results through web articles or social media, please credit the work in a way that makes its connection to OSECHI clear, and share it as a community activity example where possible.\nExample Acknowledgment Text # Japanese: 本活動はOSECHIプロジェクトの支援を受けたものです。 English: This work was supported by the OSECHI project. 9. Questions and Support # For anything not covered by these guidelines, or if you\u0026rsquo;re unsure how to judge a situation, please consult the core members. We\u0026rsquo;ll respond flexibly depending on the circumstances.\n10. Disclaimer # The content of these guidelines may change in the future.\nCore members: Ueno, Nakamori, Shoji, Shota, Yoshioka\n","externalUrl":null,"permalink":"/en/guidelines/community/","section":"Guidelines","summary":"Introduction # These guidelines summarize the basic mindset and a few requests for anyone taking part in activities using OSECHI. They are not meant to be enforced as strict rules — please use them as a reference when you’re unsure how to proceed with a specific activity.\n1. Purpose and Values # The OSECHI community aims to advance education and science outreach through the development and use of the compact cosmic ray detector OSECHI. We value an environment where anyone can participate regardless of their position — researchers and outreach staff at universities and research institutes, teachers, students, and others.\n","title":"Participation Guidelines","type":"guidelines"},{"content":" Code of Conduct # The OSECHI community aims to be a place where anyone can participate safely, regardless of position or experience. This page summarizes our code of conduct within the community.\nFor our day-to-day approach to activities and a few requests, please also see the Community and Participation Guidelines.\nThis code of conduct is based on the Contributor Covenant, version 2.1, widely adopted across open source communities.\nOur Pledge # We as members, contributors, and leaders pledge to make participation in our community a harassment-free experience for everyone, regardless of age, body size, visible or invisible disability, ethnicity, sex characteristics, gender identity and expression, level of experience, education, socio-economic status, nationality, personal appearance, race, caste, color, religion, or sexual identity and orientation.\nWe pledge to act and interact in ways that contribute to an open, welcoming, diverse, inclusive, and healthy community.\nOur Standards # Examples of behavior that contributes to a positive environment for our community include:\nDemonstrating empathy and kindness toward other people Being respectful of differing opinions, viewpoints, and experiences Giving and gracefully accepting constructive feedback Accepting responsibility and apologizing to those affected by our mistakes, and learning from the experience Focusing on what is best not just for us as individuals, but for the overall community Examples of unacceptable behavior include:\nThe use of sexualized language or imagery, and sexual attention or advances of any kind Trolling, insulting or derogatory comments, and personal or political attacks Public or private harassment Publishing others\u0026rsquo; private information, such as a physical or email address, without their explicit permission Other conduct which could reasonably be considered inappropriate in a professional setting Enforcement Responsibilities # Community leaders are responsible for clarifying and enforcing our standards of acceptable behavior and will take appropriate and fair corrective action in response to any behavior that they deem inappropriate, threatening, offensive, or harmful.\nCommunity leaders have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, and will communicate reasons for moderation decisions when appropriate.\nScope # This Code of Conduct applies within all community spaces, and also applies when an individual is officially representing the community in public spaces. Examples of representing our community include using an official e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event.\nEnforcement # Instances of abusive, harassing, or otherwise unacceptable behavior may be reported to the core members. All complaints will be reviewed and investigated promptly and fairly. All community leaders are obligated to respect the privacy and security of the reporter of any incident.\nEnforcement Guidelines # Community leaders will follow these guidelines in determining the consequences for any action they deem in violation of this Code of Conduct.\n1. Correction # Community Impact: Use of inappropriate language or other behavior deemed unprofessional or unwelcome in the community.\nConsequence: A private, written warning from community leaders, providing clarity around the nature of the violation and an explanation of why the behavior was inappropriate. A public apology may be requested.\n2. Warning # Community Impact: A violation through a single incident or series of actions.\nConsequence: A warning with consequences for continued behavior. No interaction with the people involved, including unsolicited interaction with those enforcing the Code of Conduct, for a specified period of time. This includes avoiding interactions in community spaces as well as external channels like social media. Violating these terms may lead to a temporary or permanent ban.\n3. Temporary Ban # Community Impact: A serious violation of community standards, including sustained inappropriate behavior.\nConsequence: A temporary ban from any sort of interaction or public communication with the community for a specified period of time. No public or private interaction with the people involved, including unsolicited interaction with those enforcing the Code of Conduct, is allowed during this period. Violating these terms may lead to a permanent ban.\n4. Permanent Ban # Community Impact: Demonstrating a pattern of violation of community standards, including sustained inappropriate behavior, harassment of an individual, or aggression toward or disparagement of classes of individuals.\nConsequence: A permanent ban from any sort of public interaction within the community.\nAttribution # This Code of Conduct is adapted from the Contributor Covenant, version 2.1, available at https://www.contributor-covenant.org/version/2/1/code_of_conduct.html, customized for the OSECHI community.\n","externalUrl":null,"permalink":"/en/guidelines/conduct/","section":"Guidelines","summary":"Code of Conduct # The OSECHI community aims to be a place where anyone can participate safely, regardless of position or experience. This page summarizes our code of conduct within the community.\nFor our day-to-day approach to activities and a few requests, please also see the Community and Participation Guidelines.\nThis code of conduct is based on the Contributor Covenant, version 2.1, widely adopted across open source communities.\n","title":"Code Of Conduct","type":"guidelines"},{"content":"https://gitlab.com/osechi/kazunoko\nA lightweight serial communication library for OSECHI.\n","externalUrl":null,"permalink":"/en/repos/kazunoko/","section":"Repositories","summary":"https://gitlab.com/osechi/kazunoko\nA lightweight serial communication library for OSECHI.\n","title":"kazunoko","type":"repos"},{"content":"Taikanezan-cho, Toyonaka, Osaka, Japan\nToyonaka Campus\nGraduate School of Science\nWebsite YouTube X Facebook Instagram LinkedIn ","externalUrl":null,"permalink":"/en/institutions/osaka/","section":"Participating Institutes","summary":"Taikanezan-cho, Toyonaka, Osaka, Japan\n","title":"Osaka University","type":"institutions"},{"content":"Professor, Faculty of Arts and Science, Kyushu University\n2019 - present\n","externalUrl":null,"permalink":"/en/members/tamaki-yoshioka/","section":"Members","summary":"Professor, Faculty of Arts and Science, Kyushu University\n","title":"Tamaki Yoshioka","type":"members"},{"content":"Even with a scintillator and photodetector working together, not every signal that comes out is caused by a muon. Thermal and electrical noise can produce signals that look a lot like the real thing. Coincidence is a technique that combines multiple detector layers to filter out this noise and select only the events where a muon truly passed through.\nThreshold # A photodetector\u0026rsquo;s signal always contains a mix of genuine muon signals and faint background noise. The boundary value used to distinguish noise from signal is called the threshold; an event is only recorded when the signal exceeds it.\nSetting the threshold high reduces noise but risks missing weak, genuine signals. Setting it low increases sensitivity but makes noise easier to mistake for a signal. A single layer alone can\u0026rsquo;t escape this tradeoff between sensitivity and noise rejection.\nDetecting Multiple Layers at Once # Coincidence setups stack two or more detector layers. Because muons travel in nearly straight lines, a genuine muon event passes through all the layers at almost the same instant, triggering a signal above threshold in each one.\nThermal and electrical noise, on the other hand, occurs independently and at random times in each layer, so the odds of multiple layers firing by coincidence are very low. By recording an event only when every layer fires within a very short time window, this rule filters out noise that a single layer could never avoid on its own.\nWhy Noise Drops So Much # Even if a single layer generates, say, 100 noise pulses per second, the chance of two layers coincidentally firing within a microsecond of each other is orders of magnitude smaller than either layer\u0026rsquo;s rate alone. Adding more layers drives the odds of a chance coincidence down further still, letting you select genuine muon events with much higher confidence.\nCoincidence Measurement with OSECHI # Each OSECHI unit stacks three layers of plastic scintillator. Recording an event only when all three layers fire at nearly the same instant lets a single unit reject noise more effectively than any one layer could on its own.\nCombining multiple OSECHI units, and looking for events that occur simultaneously across detectors placed some distance apart, could open up measurements no single detector could capture alone — such as spread-out phenomena like an air shower. That\u0026rsquo;s still a goal we\u0026rsquo;re working toward, and one of the research topics we hope to grow together with participants.\n","externalUrl":null,"permalink":"/en/learn/coincidence/","section":"Learning Guide","summary":"Even with a scintillator and photodetector working together, not every signal that comes out is caused by a muon. Thermal and electrical noise can produce signals that look a lot like the real thing. Coincidence is a technique that combines multiple detector layers to filter out this noise and select only the events where a muon truly passed through.\nThreshold # A photodetector’s signal always contains a mix of genuine muon signals and faint background noise. The boundary value used to distinguish noise from signal is called the threshold; an event is only recorded when the signal exceeds it.\n","title":"What is Coincidence?","type":"learn"},{"content":"https://gitlab.com/osechi/omochi\nA detector simulator for OSECHI.\n","externalUrl":null,"permalink":"/en/repos/omochi/","section":"Repositories","summary":"https://gitlab.com/osechi/omochi\nA detector simulator for OSECHI.\n","title":"omochi","type":"repos"},{"content":"Professor, Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)\n2022 - present\n","externalUrl":null,"permalink":"/en/members/satoshi-mihara/","section":"Members","summary":"Professor, Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)\n","title":"Satoshi Mihara","type":"members"},{"content":"Shonan Village, Hayama, Miura, Kanagawa 240-0193, Japan\nHayama Campus (Headquarters)\nWebsite YouTube X Facebook ","externalUrl":null,"permalink":"/en/institutions/sokendai/","section":"Participating Institutes","summary":"Shonan Village, Hayama, Miura, Kanagawa 240-0193, Japan\n","title":"The Graduate University for Advanced Studies (SOKENDAI)","type":"institutions"},{"content":"When a primary cosmic ray enters the atmosphere, the single particle branches out again and again, producing a swarm of countless secondary particles. This phenomenon is called an air shower. By the time it reaches the ground, the shower has become a group of particles arriving simultaneously across a wide area.\nHow a Shower Spreads # When a primary cosmic ray collides with a nucleus in the upper atmosphere, it produces secondary particles such as pions. These particles go on to react with other nuclei or decay, multiplying the particle count in a cascading chain reaction.\nThe resulting particles travel roughly along the direction of the original primary cosmic ray as they spread out toward the ground. As a result, at ground level, large numbers of muons and other particles arrive almost simultaneously over an area ranging from tens or hundreds of meters — or, for the largest showers, several kilometers — across.\nShower Size and Energy # The higher the energy of the original primary cosmic ray, the more secondary particles are produced and the wider the shower spreads. Showers from extremely high-energy cosmic rays can spread particles across several kilometers by the time they reach the ground.\nObserving from Multiple Sites # A single detector can only catch a fraction of the muons passing through a shower. But by placing multiple detectors at separate locations and looking for events that occur at nearly the same instant, you can link together multiple hits that trace back to the same air shower.\nSpacing detectors farther apart increases the chance of catching larger, higher-energy showers. Placing them closer together instead lets you study the particle distribution within a single shower in more detail.\nWorking Toward Air Shower Observation with OSECHI # A single OSECHI unit can already record muon events through coincidence measurement. Building on that to run multiple units simultaneously at separate locations, searching for air-shower events, is a measurement we\u0026rsquo;re still working to realize.\nIf many OSECHI units deployed across a wide area could collect data at the same time, it would become a citizen-science effort to observe large-scale cosmic ray showers. Making that observation a reality together with participants is one of the goals OSECHI is aiming for.\n","externalUrl":null,"permalink":"/en/learn/air-shower/","section":"Learning Guide","summary":"When a primary cosmic ray enters the atmosphere, the single particle branches out again and again, producing a swarm of countless secondary particles. This phenomenon is called an air shower. By the time it reaches the ground, the shower has become a group of particles arriving simultaneously across a wide area.\nHow a Shower Spreads # When a primary cosmic ray collides with a nucleus in the upper atmosphere, it produces secondary particles such as pions. These particles go on to react with other nuclei or decay, multiplying the particle count in a cascading chain reaction.\n","title":"What is Air Shower Observation?","type":"learn"},{"content":"https://gitlab.com/osechi/datemaki\nA data management tool for OSECHI (planned).\n","externalUrl":null,"permalink":"/en/repos/datemaki/","section":"Repositories","summary":"https://gitlab.com/osechi/datemaki\nA data management tool for OSECHI (planned).\n","title":"datemaki","type":"repos"},{"content":"3190 Gofuku, Toyama-shi, Toyama 930-8555, Japan\nGofuku Campus\nWebsite YouTube X Facebook Instagram LinkedIn ","externalUrl":null,"permalink":"/en/institutions/toyama/","section":"Participating Institutes","summary":"3190 Gofuku, Toyama-shi, Toyama 930-8555, Japan\n","title":"University of Toyama","type":"institutions"},{"content":"Muography uses the high penetrating power of muons to image the internal structure of large objects. Just as X-rays image the human body, muography \u0026ldquo;sees through\u0026rdquo; buildings, volcanoes, and pyramids.\nHow Muography Works # As cosmic-ray muons pass through matter, they travel in a straight line while gradually losing energy. Denser material absorbs more muons, so the number of muons observed on the far side of an object varies with the density of the material along the path they traveled.\nBy measuring the number of muons arriving from many directions and comparing how much each is attenuated, it\u0026rsquo;s possible to image the internal density distribution — much like an X-ray. Unlike X-rays, which can only penetrate a few centimeters of matter, muons can pass through tens to hundreds of meters of rock, making it possible to image the interior of mountains and massive structures.\nApplications # Volcano and Ground Imaging # Muography can non-destructively reveal how magma is distributed inside a volcano from the outside. In Japan, observations have been conducted at volcanoes such as Sakurajima and Mt. Aso. Real-time monitoring of magma movement holds promise for eruption prediction.\nImaging Large Structures # The discovery of an unknown cavity inside the Great Pyramid of Giza made global headlines in 2017. Because muons can penetrate tens of meters of stone, they can reveal the internal structure of massive stone structures. Muography is also used in nuclear decommissioning to locate fuel debris inside reactors.\nSecurity and Resource Exploration # Muography is applied to detection of nuclear materials and smuggled goods at ports and borders. It is also effective for surveying underground resources (ore deposits, cavities) as a non-destructive, non-invasive investigation method.\nWorking Toward Muography with OSECHI # Muography requires a detector that measures muons from multiple directions over an extended period. Deploying multiple OSECHI-style compact detectors over a long period should make it possible to experience the principle of muography using familiar buildings and terrain.\nThis measurement hasn\u0026rsquo;t been realized yet, but working toward it together with participants is one of the goals the OSECHI project has in view.\nReferences # Morishima, K. et al., \u0026ldquo;Discovery of a big void in Khufu\u0026rsquo;s Pyramid by observation of cosmic-ray muons,\u0026rdquo; Nature (2017). arXiv:1711.01576 Oláh, L., Tanaka, H. K. M., Ohminato, T. \u0026amp; Varga, D., \u0026ldquo;High-definition and low-noise muography of the Sakurajima volcano with gaseous tracking detectors,\u0026rdquo; Scientific Reports (2018). Open access (PMC) ","externalUrl":null,"permalink":"/en/learn/muography/","section":"Learning Guide","summary":"Muography uses the high penetrating power of muons to image the internal structure of large objects. Just as X-rays image the human body, muography “sees through” buildings, volcanoes, and pyramids.\nHow Muography Works # As cosmic-ray muons pass through matter, they travel in a straight line while gradually losing energy. Denser material absorbs more muons, so the number of muons observed on the far side of an object varies with the density of the material along the path they traveled.\n","title":"What is Muography?","type":"learn"},{"content":"Assistant Professor, Faculty of Science, University of Toyama\n2025 - present\n","externalUrl":null,"permalink":"/en/members/yuuki-nakano/","section":"Members","summary":"Assistant Professor, Faculty of Science, University of Toyama\n","title":"Yuuki Nakano","type":"members"},{"content":"https://gitlab.com/osechi/kuromame\nA lightweight online monitor for OSECHI (planned).\n","externalUrl":null,"permalink":"/en/repos/kuromame/","section":"Repositories","summary":"https://gitlab.com/osechi/kuromame\nA lightweight online monitor for OSECHI (planned).\n","title":"kuromame","type":"repos"},{"content":"Graduate Student, Graduate School of Sciences, Kyushu University\n2025 - present\n","externalUrl":null,"permalink":"/en/members/masaki-tanida/","section":"Members","summary":"Graduate Student, Graduate School of Sciences, Kyushu University\n","title":"Masaki Tanida","type":"members"},{"content":"Cosmic ray research once required large, dedicated equipment found only at universities and research institutes. As detectors have become smaller and cheaper in recent years, the field has grown into a form of citizen science, where schools and individuals can take part in genuine measurement.\nWhat is Citizen Science? # Citizen science is a style of research where members of the public — not just professional researchers — take part in observation, data collection, and analysis. It has produced results across many fields, from amateur astronomers discovering new celestial objects to volunteers logging biodiversity sightings.\nIn cosmic ray research, citizen science\u0026rsquo;s strength lies in spreading many detectors across a wide area. A detector network on a scale no single institution could deploy alone becomes possible through the combined effort of many participants.\nProjects Abroad # CRAYFIS # A project that repurposes smartphone camera sensors as cosmic ray detectors. By running an app on phones around the world, it aims to build a massive detector network out of everyday devices.\nQuarkNet # A U.S. education program for high school and university students, in which participants use muon detectors to collect and analyze real cosmic ray data. It\u0026rsquo;s a well-known model for combining education with genuine data collection.\nCosmic Watch # A desktop muon detector kit developed at MIT (Massachusetts Institute of Technology), built from inexpensive parts. Its design files and build instructions are published openly, aiming to let schools and individuals anywhere build their own muon detector. It shares a similar philosophy with OSECHI.\nCREDO # An international project that networks detectors worldwide — from smartphones to dedicated instruments — to cooperatively observe the large-scale air showers produced by ultra-high-energy cosmic rays.\nActivity in Japan # Kasoku Kitchen # A Japanese group supporting middle and high school students\u0026rsquo; cosmic ray and particle physics research. It lends out detectors such as Cosmic Watch to students nationwide and, through online mentoring from university student mentors, lets each student pursue observation and research on their own theme. It participates as Japan\u0026rsquo;s representative in the Global Cosmic Group, a network of cosmic ray outreach organizations from around the world.\nSoramame # An app developed at Kanagawa University that detects cosmic rays using the camera sensor (CMOS image sensor) built into smartphones and tablets. No dedicated detector is needed — a smartphone you already own can serve as the observation device. Detected data is collected in the cloud so it can be compared with observations from users worldwide, and the project also proposes repurposing old, unused devices as dedicated observation units.\nThundercloud Project (雷雲プロジェクト) # A citizen science project led by Kyoto University, Kanazawa University, and other research institutions. It installs compact radiation monitors in the homes of citizen volunteers and observes gamma rays reaching the ground from thunderclouds at multiple sites simultaneously, studying the connection between lightning and cosmic rays. In 2021, the project succeeded in detecting thundercloud-origin gamma rays simultaneously at multiple sites in Kanazawa City.\nShinshu Cosmic Ray (信大コズミックレイ) # An outreach initiative led by researchers at Shinshu University to raise public awareness of cosmic rays. Rather than focusing on data collection, it aims to make the word \u0026ldquo;cosmic ray\u0026rdquo; itself more familiar, through VR experience exhibits and videos that convey the appeal of cosmic ray research. It serves less as an observation network and more as an entry point that broadens interest in the phenomenon of cosmic rays.\nOSECHI and Citizen Science # OSECHI is part of this same movement, both in Japan and abroad. Anyone who encounters the detector at a school or local event can go on to become part of the team collecting observation data, lowering the barrier between experts and the public. By keeping measurement data and research questions open, OSECHI aims to create a space where anyone can take part in cosmic ray research.\nReferences # Whiteson, D. et al., \u0026ldquo;Observing Ultra-High Energy Cosmic Rays with Smartphones.\u0026rdquo; arXiv:1410.2895 (CRAYFIS) Axani, S. N. et al., \u0026ldquo;The CosmicWatch Desktop Muon Detector: a self-contained, pocket sized particle detector.\u0026rdquo; arXiv:1801.03029 (Cosmic Watch) Homola, P. et al., \u0026ldquo;Public engagement as a scientific tool to implement multi-messenger strategies with the Cosmic-Ray Extremely Distributed Observatory.\u0026rdquo; arXiv:1908.09734 (CREDO) Takano, W., Udo, S., Shiomi, A. \u0026amp; Hibino, K., \u0026ldquo;Development of a cosmic ray detector using CMOS sensors embedded in smartphones and Raspberry Pi devices,\u0026rdquo; Experimental Astronomy. arXiv:2607.02106 (Soramame) Yuasa, T., Wada, Y., Enoto, T. et al., \u0026ldquo;Thundercloud Project: Exploring high-energy phenomena in thundercloud and lightning,\u0026rdquo; Progress of Theoretical and Experimental Physics (2020). Open access (Thundercloud Project) ","externalUrl":null,"permalink":"/en/learn/citizen-science/","section":"Learning Guide","summary":"Cosmic ray research once required large, dedicated equipment found only at universities and research institutes. As detectors have become smaller and cheaper in recent years, the field has grown into a form of citizen science, where schools and individuals can take part in genuine measurement.\nWhat is Citizen Science? # Citizen science is a style of research where members of the public — not just professional researchers — take part in observation, data collection, and analysis. It has produced results across many fields, from amateur astronomers discovering new celestial objects to volunteers logging biodiversity sightings.\n","title":"What is Citizen Science in Cosmic Ray Observation?","type":"learn"},{"content":"1-4-12 Kojirakawa-machi, Yamagata-shi, Yamagata 990-8560, Japan\nKojirakawa Campus\nFaculty of Science\nWebsite YouTube X Facebook Instagram LinkedIn ","externalUrl":null,"permalink":"/en/institutions/yamagata/","section":"Participating Institutes","summary":"1-4-12 Kojirakawa-machi, Yamagata-shi, Yamagata 990-8560, Japan\n","title":"Yamagata University","type":"institutions"},{"content":"https://gitlab.com/osechi/cookbooks\nA collection of DAQ recipes using kazunoko and datemaki.\n","externalUrl":null,"permalink":"/en/repos/cookbooks/","section":"Repositories","summary":"https://gitlab.com/osechi/cookbooks\nA collection of DAQ recipes using kazunoko and datemaki.\n","title":"cookbooks","type":"repos"},{"content":"239-3 Kurisaki, Honjo-shi, Saitama 367-0032, Japan\nHonjo Campus\nWebsite ","externalUrl":null,"permalink":"/en/institutions/waseda-honjo/","section":"Participating Institutes","summary":"239-3 Kurisaki, Honjo-shi, Saitama 367-0032, Japan\n","title":"Waseda University Honjo Senior High School","type":"institutions"},{"content":"Cosmic rays have been studied for over a century since their discovery in 1912, yet some fundamental questions remain unanswered. Here are a few of the open problems researchers around the world are still working on.\nWhere Do the Highest-Energy Cosmic Rays Come From? # Observations have confirmed that, on rare occasions, cosmic rays reach Earth carrying an almost unbelievable amount of energy for a single particle — these are called ultra-high-energy cosmic rays. The highest energies ever recorded far exceed what humanity\u0026rsquo;s largest particle accelerator, the LHC, can produce.\nFew astronomical objects could impart that much energy to a particle; supernova remnants and active galactic nuclei (AGN) are candidates, but which objects actually produce ultra-high-energy cosmic rays is still unidentified. Because these events are extremely rare, solving the mystery requires long-term observation with a vast network of detectors — a major obstacle to gathering enough data.\nA recent example came in 2021, when the Telescope Array experiment in Utah, USA, observed a cosmic ray with an almost unimaginable energy of 244 exa-electronvolts. The discovery, announced in 2023 by a team that included Japanese researchers, was named the \u0026ldquo;Amaterasu particle\u0026rdquo; after the sun goddess of Japanese mythology. The second-highest-energy particle ever recorded, its source has still not been identified — a concrete example of this open question.\nThe GZK Limit Puzzle # In theory, ultra-high-energy cosmic rays should lose energy as they travel through space by colliding with the cosmic microwave background (the afterglow of the Big Bang), meaning they shouldn\u0026rsquo;t be able to reach us from extremely distant sources. This predicted cutoff is known as the GZK limit.\nMost observed cosmic rays are broadly consistent with this prediction, but some reported events — including the Amaterasu particle — appear to exceed the GZK limit, and the debate continues. Gathering more data and improving measurement precision are seen as key to resolving this puzzle.\nThe Mystery of Cosmic Ray Composition # The mix of particles that make up cosmic rays — protons, helium nuclei, heavier nuclei, and so on — is known to shift with energy. This shifting composition offers clues about what kind of astronomical object accelerated the particles and how, but the limits of current observation technology mean it hasn\u0026rsquo;t yet been pinned down precisely.\nOSECHI and the Future of Cosmic Ray Research # Many of these open questions concern ultra-high-energy cosmic rays, an extremely rare phenomenon that requires long-term observation by detector networks spread across the globe. Citizen science built on small detectors like OSECHI won\u0026rsquo;t solve these mysteries directly, but it broadens understanding of cosmic ray observation itself, and can help build the foundation that future research stands on.\nReferences # Telescope Array Collaboration, \u0026ldquo;An extremely energetic cosmic ray observed by a surface detector array,\u0026rdquo; Science (2023). arXiv:2311.14231 ","externalUrl":null,"permalink":"/en/learn/open-questions/","section":"Learning Guide","summary":"Cosmic rays have been studied for over a century since their discovery in 1912, yet some fundamental questions remain unanswered. Here are a few of the open problems researchers around the world are still working on.\nWhere Do the Highest-Energy Cosmic Rays Come From? # Observations have confirmed that, on rare occasions, cosmic rays reach Earth carrying an almost unbelievable amount of energy for a single particle — these are called ultra-high-energy cosmic rays. The highest energies ever recorded far exceed what humanity’s largest particle accelerator, the LHC, can produce.\n","title":"What Open Questions Remain in Cosmic Ray Research?","type":"learn"},{"content":"The muons we\u0026rsquo;ve discussed so far are \u0026ldquo;cosmic-ray muons,\u0026rdquo; produced when cosmic rays collide with the atmosphere. Elsewhere, researchers also produce large numbers of muons artificially with accelerators, studying their properties in precise detail to probe the limits of particle physics\u0026rsquo; fundamental laws.\nMeasuring a Muon\u0026rsquo;s Tiny Deviation # Place a muon in a magnetic field and it behaves like a tiny magnet, wobbling like a spinning top. This wobbling motion is called precession, and the strength of the wobble is captured by a quantity called g-2 (the anomalous magnetic moment). g-2 can be calculated from theory with extraordinary precision, then compared directly against a measured value from experiment. Past experiments have reported a g-2 value that deviates slightly from the theoretical prediction, drawing attention as a possible hint of an as-yet-undiscovered particle or force.\nThe muon g-2/EDM experiment underway at J-PARC cools muons and then re-accelerates them, producing a tighter, more tightly bunched stream of muons — called a beam — than before, letting researchers measure the g-2 deviation with a smaller apparatus and greater precision. Alongside g-2, the experiment also looks for the electric dipole moment (EDM): any imbalance in how positive and negative charge are distributed inside the muon. Combining both measurements, g-2 and EDM, the experiment searches for physics the Standard Model can\u0026rsquo;t explain.\nCatching a Muon Turn Into an Electron # Electrons and muons are like siblings — closely related particles that differ mainly in mass. In the Standard Model, a particle\u0026rsquo;s \u0026ldquo;type\u0026rdquo; — technically called its lepton flavor — is thought to be conserved almost exactly from before a reaction to after. That means a muon essentially never turns directly into an electron. If that reaction ever did happen, it would be an instance of charged lepton flavor violation (CLFV) — something the Standard Model can\u0026rsquo;t explain.\nThe COMET experiment, underway at the high-intensity proton accelerator facility J-PARC, is an international project aiming to search for this muon-to-electron transformation with unprecedented precision. The experiment proceeds in stages: the first stage, called Phase-I, searches with greatly improved sensitivity, and its results will feed into a second stage, Phase-II, which aims to push sensitivity more than 100 times further still. If this transformation were ever observed, even once, it would be decisive evidence for new physics beyond the Standard Model.\nReferences # Moritsu, M. (on behalf of the COMET Collaboration), \u0026ldquo;Search for Muon-to-Electron Conversion with the COMET Experiment,\u0026rdquo; Universe 8, 196 (2022). https://doi.org/10.3390/universe8040196 J-PARC muon g-2/EDM Collaboration, \u0026ldquo;Overview,\u0026rdquo; https://g-2.kek.jp/overview/ ","externalUrl":null,"permalink":"/en/learn/muon-physics/","section":"Learning Guide","summary":"The muons we’ve discussed so far are “cosmic-ray muons,” produced when cosmic rays collide with the atmosphere. Elsewhere, researchers also produce large numbers of muons artificially with accelerators, studying their properties in precise detail to probe the limits of particle physics’ fundamental laws.\nMeasuring a Muon’s Tiny Deviation # Place a muon in a magnetic field and it behaves like a tiny magnet, wobbling like a spinning top. This wobbling motion is called precession, and the strength of the wobble is captured by a quantity called g-2 (the anomalous magnetic moment). g-2 can be calculated from theory with extraordinary precision, then compared directly against a measured value from experiment. Past experiments have reported a g-2 value that deviates slightly from the theoretical prediction, drawing attention as a possible hint of an as-yet-undiscovered particle or force.\n","title":"Muons and New Physics","type":"learn"},{"content":"The muon is the star of the show in a cosmic-ray measurement like OSECHI\u0026rsquo;s, but for many other experiments it\u0026rsquo;s treated as background — unwanted noise that sometimes turns it into an unwelcome intruder.\nWhy Muons Get in the Way # Roughly 10,000 muons rain down on every square meter of the Earth\u0026rsquo;s surface each minute. For experiments where keeping background to an absolute minimum is critical — searches for neutrino interactions or dark matter, for instance — this flood of muons leaves countless signals in a detector, burying the real signal researchers are looking for.\nWhy Experiments Go Underground # To avoid this background, many neutrino and dark matter experiments, Super-Kamiokande among them, are built deep underground inside mountains. Muons have high penetrating power, but most still lose their energy and stop, or get absorbed, while passing through hundreds to thousands of meters of rock.\nSuper-Kamiokande, located about 1,000 m underground near Kamioka, Gifu Prefecture, sees roughly one hundred-thousandth the muon flux found at the surface. This rock shielding creates a quiet enough environment to detect extremely rare events like neutrino interactions.\nUsing Muons to Calibrate Detectors # At the same time, cosmic-ray muons have their own appeal: they\u0026rsquo;re a source of radiation you can get your hands on for free. Since muons are charged particles that travel in nearly straight lines at close to the speed of light and rain down naturally everywhere, at all times, they serve as a standard particle source that doesn\u0026rsquo;t require an accelerator.\nCosmic-ray muons remain background even at accelerator-based experiments — but seen from a different angle, at the right moment, that same background becomes a tool for evaluating a detector\u0026rsquo;s performance before real data-taking begins. For example, cosmic-ray muons are commonly used to calibrate position reconstruction — how accurately a detector can reconstruct the path a muon took — and energy resolution, how precisely it can read off energy from the size of a signal. Running a \u0026ldquo;cosmic-ray test\u0026rdquo; to confirm a detector is working correctly — before startup or after routine maintenance — is a standard step in many experiments, underground or accelerator-based alike.\nReferences # Woodley, W., Fedynitch, A. \u0026amp; Piro, M.-C., \u0026ldquo;Cosmic Ray Muons in Laboratories Deep Underground,\u0026rdquo; arXiv:2406.10339 (2024). ","externalUrl":null,"permalink":"/en/learn/muon-background/","section":"Learning Guide","summary":"The muon is the star of the show in a cosmic-ray measurement like OSECHI’s, but for many other experiments it’s treated as background — unwanted noise that sometimes turns it into an unwelcome intruder.\nWhy Muons Get in the Way # Roughly 10,000 muons rain down on every square meter of the Earth’s surface each minute. For experiments where keeping background to an absolute minimum is critical — searches for neutrino interactions or dark matter, for instance — this flood of muons leaves countless signals in a detector, burying the real signal researchers are looking for.\n","title":"Muons and Underground Experiments","type":"learn"},{"content":"Muons produced in bulk by an accelerator power more than just precision measurements — they\u0026rsquo;re also put to work in applied research. One application drawing particular attention in recent years is using muons to investigate cultural artifacts, and researchers around the world are also, right now, building accelerators purpose-built for muons.\nSeeing Inside Cultural Artifacts With Muons # Accelerator-made muons are also put to work in collaboration with archaeology, history, and conservation science — the field devoted to preserving and restoring cultural artifacts. When a negatively charged muon is aimed at an object, it gets captured by an atomic nucleus and, in the process, emits X-rays characteristic of that particular element (muonic X-rays). By measuring these X-rays, researchers can map an object\u0026rsquo;s elemental distribution deep below the surface, unlike conventional X-ray analysis, which can only probe near the surface, all without cutting into or damaging it in any way.\nMuon beams are starting to be used to analyze historical artifacts that are difficult to examine destructively — metal Buddhist statues, swords, objects excavated from archaeological sites. In Japan, a muonic X-ray measurement system for cultural heritage is taking shape at J-PARC, with published analyses of Edo-period archaeological artifacts already among its results. Projects like these are often driven jointly by particle physicists alongside archaeologists, historians, and conservation scientists, making this a growing interdisciplinary field.\nLearning to Accelerate a Muon Freely # Accelerating a muon is a far harder challenge than accelerating an electron or a proton. A muon is far heavier than an electron yet much lighter than a proton, so neither an electron accelerator nor a proton accelerator can simply be reused as-is. On top of that, its average lifetime is only about 2.2 microseconds, adding the constraint that producing, cooling, and accelerating it up to its target energy all have to happen within that fleeting window.\nIn 2024, a research group at J-PARC announced the world\u0026rsquo;s first breakthrough on this challenge with a muon linear accelerator built from scratch for the purpose. A reliable, purpose-built accelerator that can produce a high-quality muon beam with well-defined direction and speed doesn\u0026rsquo;t just sharpen the precision of the search for new physics in the muon — it also gives non-destructive analysis techniques further momentum. Development of accelerators like this one is continuing around the world, with an eye on an even bigger goal: building a muon collider that would collide muons — far heavier than electrons — head-on. Such a machine could reach higher collision energies in a far more compact footprint than existing colliders.\nReferences # Otani, M., \u0026ldquo;First muon acceleration and muon linear accelerator for measuring the muon anomalous magnetic moment and electric dipole moment,\u0026rdquo; Progress of Theoretical and Experimental Physics 2022, 052C01 (2022). https://doi.org/10.1093/ptep/ptac067 \u0026ldquo;World\u0026rsquo;s First Cooling and Acceleration of Muon — The First Muon Accelerator Finally Coming to a Reality,\u0026rdquo; J-PARC Press Release (2024). https://j-parc.jp/c/en/press-release/2024/05/23001341.html Chiu, I.-H. et al., \u0026ldquo;Nondestructive 3D elemental imaging of Edo\u0026rsquo;s archaeological artifacts via muonic X-ray measurements,\u0026rdquo; npj Heritage Science 13, 154 (2025). https://doi.org/10.1038/s40494-025-01741-8 ","externalUrl":null,"permalink":"/en/learn/muon-acceleration/","section":"Learning Guide","summary":"Muons produced in bulk by an accelerator power more than just precision measurements — they’re also put to work in applied research. One application drawing particular attention in recent years is using muons to investigate cultural artifacts, and researchers around the world are also, right now, building accelerators purpose-built for muons.\nSeeing Inside Cultural Artifacts With Muons # Accelerator-made muons are also put to work in collaboration with archaeology, history, and conservation science — the field devoted to preserving and restoring cultural artifacts. When a negatively charged muon is aimed at an object, it gets captured by an atomic nucleus and, in the process, emits X-rays characteristic of that particular element (muonic X-rays). By measuring these X-rays, researchers can map an object’s elemental distribution deep below the surface, unlike conventional X-ray analysis, which can only probe near the surface, all without cutting into or damaging it in any way.\n","title":"Muons and Accelerators","type":"learn"},{"content":"7-1 Yagumo-cho, Niihama-shi, Ehime 792-8580, Japan\nNiihama Campus\nWebsite ","externalUrl":null,"permalink":"/en/institutions/niihama-kosen/","section":"Participating Institutes","summary":"7-1 Yagumo-cho, Niihama-shi, Ehime 792-8580, Japan\n","title":"National Institute of Technology, Niihama College","type":"institutions"},{"content":"700 Dannoharu, Oita-shi, Oita 870-1192, Japan\nDannoharu Campus\nWebsite YouTube X Facebook Instagram ","externalUrl":null,"permalink":"/en/institutions/oita/","section":"Participating Institutes","summary":"700 Dannoharu, Oita-shi, Oita 870-1192, Japan\n","title":"Oita University","type":"institutions"},{"content":"","date":"2026-09-06","externalUrl":null,"permalink":"/en/authors/","section":"Authors","summary":"","title":"Authors","type":"authors"},{"content":"","date":"2026-09-06","externalUrl":null,"permalink":"/en/categories/","section":"Categories","summary":"","title":"Categories","type":"categories"},{"content":"On Sunday, September 6, 2026, we will hold the Japan Society for the Promotion of Science\u0026rsquo;s \u0026ldquo;Hirameki Tokimeki Science — Welcome to the University Lab! KAKENHI\u0026rdquo; program \u0026ldquo;Watch the Sun with Neutrinos — How Do We Block the Troublesome Cosmic-Ray Muons?\u0026rdquo; at the Gofuku Campus of the Faculty of Science, University of Toyama. The event will let 20 high school students experience particle and astrophysics research through lectures and hands-on activities.\nThe Super-Kamiokande experiment observes neutrinos 1000 m underground, where cosmic-ray muons act as a \u0026ldquo;troublesome\u0026rdquo; background. Focusing on these muons, participants will build their own OSECHI muon detectors and carry out an observation experiment. The program will be led by Associate Professor Yuki Nakano (University of Toyama, principal investigator) and Lecturer Motoko Fujiwara (Kyushu University, collaborator), with graduate and undergraduate students supporting the hands-on sessions.\nEvent Overview # Date: Sunday, September 6, 2026, 9:30 gathering – 17:00 dismissal Venue: Gofuku Campus, Faculty of Science, University of Toyama Audience: 20 high school students (mainly from Toyama and neighboring prefectures) Fee: Free (lunch provided by the organizers) Application deadline: Friday, July 31, 2026, first-come first-served Program Content # Learn about cosmic rays, neutrinos, and muons Assemble an OSECHI muon detector Observe muons Analyze the observed data Tour the university\u0026rsquo;s research facilities Schedule # Time Activity 9:30 Registration and gathering 10:00 Orientation 10:30 Explanation of the KAKENHI grant 10:40 Lecture: \u0026ldquo;What Are Cosmic Rays (Neutrinos, Muons)?\u0026rdquo; (Motoko Fujiwara, Kyushu University) 11:40 Lecture: \u0026ldquo;Solar Neutrinos and the OSECHI Detector\u0026rdquo; (Yuki Nakano, University of Toyama) 13:20 Building the OSECHI detector 14:20 Muon observation experiment with OSECHI 15:20 Data analysis and discussion 16:00 Lab tour 16:30 Closing ceremony and \u0026ldquo;Future Doctorate\u0026rdquo; certificates 17:00 Dismissal Related Links # Hirameki Tokimeki Science 2026 (Astroparticle Physics Laboratory, University of Toyama) Program Details (Grant No. 26HT0063) ","date":"2026-09-06","externalUrl":null,"permalink":"/en/posts/2026/249/","section":"Posts","summary":"On Sunday, September 6, 2026, we will hold the Japan Society for the Promotion of Science’s “Hirameki Tokimeki Science — Welcome to the University Lab! KAKENHI” program “Watch the Sun with Neutrinos — How Do We Block the Troublesome Cosmic-Ray Muons?” at the Gofuku Campus of the Faculty of Science, University of Toyama. The event will let 20 high school students experience particle and astrophysics research through lectures and hands-on activities.\n","title":"We Will Hold \"Hirameki Tokimeki Science\" — Watch the Sun with Neutrinos: How Do We Block the Troublesome Cosmic-Ray Muons? — at University of Toyama!","type":"posts"},{"content":"The invisible universe, visible on the ground.\nHigh-speed particles called \u0026ldquo;cosmic rays\u0026rdquo; pour down on us from space, thousands of times every second. Some of them become muons — highly penetrating particles now making headlines for their use in \u0026ldquo;seeing inside\u0026rdquo; ancient pyramids and active volcanoes.\nWe wanted to make that kind of cutting-edge research something anyone could experience at school or in their community. That\u0026rsquo;s what led to OSECHI, a compact cosmic-ray detector.\nThis project brings together members from universities and research institutes across the country. It\u0026rsquo;s still very much a work in progress, but we\u0026rsquo;re having fun building it — come join us if you\u0026rsquo;re interested!\nGet Started # Learn the basics of cosmic rays and muons, all the way to the research frontier, in our Learning Guide Find out about the project\u0026rsquo;s mission and members on the About OSECHI page Check our blog for the latest news and updates Guides by Purpose # User Guide — for anyone who wants to measure with OSECHI Organizer Guide — for teachers and event organizers Developer Guide — for anyone who wants to help build the detector or its software ","date":"2026-09-06","externalUrl":null,"permalink":"/en/","section":"OSECHI","summary":"The invisible universe, visible on the ground.\nHigh-speed particles called “cosmic rays” pour down on us from space, thousands of times every second. Some of them become muons — highly penetrating particles now making headlines for their use in “seeing inside” ancient pyramids and active volcanoes.\nWe wanted to make that kind of cutting-edge research something anyone could experience at school or in their community. That’s what led to OSECHI, a compact cosmic-ray detector.\n","title":"OSECHI","type":"page"},{"content":"","date":"2026-09-06","externalUrl":null,"permalink":"/en/categories/outreach/","section":"Categories","summary":"","title":"Outreach","type":"categories"},{"content":"Welcome to the OSECHI blog. Updates and news will be posted here soon.\n","date":"2026-09-06","externalUrl":null,"permalink":"/en/posts/","section":"Posts","summary":"Welcome to the OSECHI blog. Updates and news will be posted here soon.\n","title":"Posts","type":"posts"},{"content":"","date":"2026-09-06","externalUrl":null,"permalink":"/en/authors/shotakaha/","section":"Authors","summary":"","title":"Shotakaha","type":"authors"},{"content":"","date":"2026-09-06","externalUrl":null,"permalink":"/en/tags/","section":"Tags","summary":"","title":"Tags","type":"tags"},{"content":"","date":"2026-09-06","externalUrl":null,"permalink":"/en/tags/toyama/","section":"Tags","summary":"","title":"Toyama","type":"tags"},{"content":"","date":"2026-09-06","externalUrl":null,"permalink":"/en/tags/university-of-toyama/","section":"Tags","summary":"","title":"University of Toyama","type":"tags"},{"content":"","date":"2026-09-06","externalUrl":null,"permalink":"/tags/%E5%AF%8C%E5%B1%B1%E5%A4%A7%E5%AD%A6/","section":"Tags","summary":"","title":"富山大学","type":"tags"},{"content":"","date":"2026-09-06","externalUrl":null,"permalink":"/tags/%E5%AF%8C%E5%B1%B1%E7%9C%8C/","section":"Tags","summary":"","title":"富山県","type":"tags"},{"content":"","date":"2026-02-08","externalUrl":null,"permalink":"/en/tags/osaka/","section":"Tags","summary":"","title":"Osaka","type":"tags"},{"content":"","date":"2026-02-08","externalUrl":null,"permalink":"/en/tags/osaka-university/","section":"Tags","summary":"","title":"Osaka University","type":"tags"},{"content":"On February 8, 2026, we held the cosmic ray exploration event \u0026ldquo;Tan-Q — The Mystery of the Universe! The Wonder of Cosmic Rays\u0026rdquo; at Osaka University\u0026rsquo;s Toyonaka Campus in Osaka. The event let five high school students experience hands-on science using OSECHI.\nAssociate Professor Mizuki Yoshioka (Kyushu University) led the seminar, speaking about what cosmic rays are. From the OSECHI project, Associate Professor Yoshioka was joined by Associate Professor Kazuki Ueno (Osaka University), Specially Appointed Assistant Professor Shota Takahashi (Nagoya University), Shoji (KEK), Professor Takeyuki Nakamori (Yamagata University), Professor Satoru Mihara (KEK / SOKENDAI), and graduate students Yamada and Aramaki (Osaka University).\n","date":"2026-02-08","externalUrl":null,"permalink":"/en/posts/2026/39/","section":"Posts","summary":"On February 8, 2026, we held the cosmic ray exploration event “Tan-Q — The Mystery of the Universe! The Wonder of Cosmic Rays” at Osaka University’s Toyonaka Campus in Osaka. The event let five high school students experience hands-on science using OSECHI.\nAssociate Professor Mizuki Yoshioka (Kyushu University) led the seminar, speaking about what cosmic rays are. From the OSECHI project, Associate Professor Yoshioka was joined by Associate Professor Kazuki Ueno (Osaka University), Specially Appointed Assistant Professor Shota Takahashi (Nagoya University), Shoji (KEK), Professor Takeyuki Nakamori (Yamagata University), Professor Satoru Mihara (KEK / SOKENDAI), and graduate students Yamada and Aramaki (Osaka University).\n","title":"We Held \"Tan-Q — The Mystery of the Universe! The Wonder of Cosmic Rays\" at Osaka University!","type":"posts"},{"content":"","date":"2026-02-08","externalUrl":null,"permalink":"/tags/%E5%A4%A7%E9%98%AA%E5%A4%A7%E5%AD%A6/","section":"Tags","summary":"","title":"大阪大学","type":"tags"},{"content":"","date":"2026-02-08","externalUrl":null,"permalink":"/tags/%E5%A4%A7%E9%98%AA%E5%BA%9C/","section":"Tags","summary":"","title":"大阪府","type":"tags"},{"content":"On November 1 and 2, 2025, we held an \u0026ldquo;OSECHI Development Retreat\u0026rdquo; at University of Toyama. The OSECHI project normally holds regular meetings online, but about once a year we bring members together in person for a concentrated push on development.\nThis retreat included a first in-person meeting with the University of Toyama members who joined the project this year, and discussion was lively. On the development side, we redesigned OSECHI\u0026rsquo;s PCB and worked hands-on through how to combine the electronic parts and configure the initial setup, completing five OSECHI detectors by the end. The retreat further strengthened collaboration among members and marked an important step forward for future development.\nEvent Overview # Date: Saturday, November 1 – Sunday, November 2, 2025 Start: 15:00, Saturday, November 1 End: 13:00, Sunday, November 2 Reception: 19:00, Saturday, November 1 Venue: University of Toyama, Gofuku Campus Room: Faculty of Science Building A238 Program # Saturday, November 1 # Chair: Y. Nakano\n15:00–15:15: Opening Remarks # Speaker: Y. Nakano (University of Toyama) 15:15–15:45: Invited Talk # Understanding Global Environmental Change from Mt. Tateyama Speaker: K. Aoki (University of Toyama) 15:45–16:00: Activity Report # From Peaks to Particles: Cosmic-ray Outreach at Mt. Tateyama Speaker: M. Fujiwara (University of Toyama) Discussion 16:00–16:30: Break # 16:30–17:00: Activity Report # What is OSECHI?: Concept \u0026amp; History Speaker: K. Ueno (Osaka University) 17:00–17:30: Activity Report # Ideas for OSECHI\u0026rsquo;s Application Speaker: T. Yoshioka (Kyushu University) 17:30–18:30: Hands-on Session # Collaborative Research Using OSECHI Speaker: All participants 19:00–21:00: Reception # Venue: Duck Sunday, November 2 # Chair: Y. Nakano\n10:00–10:20: Activity Report # Recent Progress at Yamagata University Speaker: TBC 10:20–10:40: Activity Report # Recent Progress at KEK/SOKENDAI Speakers: K. Okabe \u0026amp; M. Shoji (KEK/SOKENDAI) 10:40–11:00: Activity Report # Recent Progress at University of Toyama Speakers: R. Futatsugi \u0026amp; Y. Nakano (University of Toyama) 11:00–11:30: Break # 11:30–11:50: Activity Report # Recent Progress at KMI (Nagoya University) Speaker: S. Takahashi 11:50–12:10: Activity Report # Recent Progress at Osaka University Speaker: K. Ueno (Osaka University) 12:10–12:30: Activity Report # Recent Progress at Kyushu University Speakers: T. Yoshioka \u0026amp; M. Tanida (Kyushu University) 12:30–13:00: Closing Remarks # Speaker: M. Fujiwara (University of Toyama) ","date":"2025-11-01","externalUrl":null,"permalink":"/en/posts/2025/305/","section":"Posts","summary":"On November 1 and 2, 2025, we held an “OSECHI Development Retreat” at University of Toyama. The OSECHI project normally holds regular meetings online, but about once a year we bring members together in person for a concentrated push on development.\nThis retreat included a first in-person meeting with the University of Toyama members who joined the project this year, and discussion was lively. On the development side, we redesigned OSECHI’s PCB and worked hands-on through how to combine the electronic parts and configure the initial setup, completing five OSECHI detectors by the end. The retreat further strengthened collaboration among members and marked an important step forward for future development.\n","title":"We Held a Development Retreat at University of Toyama!","type":"posts"},{"content":"","date":"2025-11-01","externalUrl":null,"permalink":"/en/categories/meeting/","section":"Categories","summary":"","title":"Meeting","type":"categories"},{"content":"","date":"2025-10-28","externalUrl":null,"permalink":"/en/tags/iwate/","section":"Tags","summary":"","title":"Iwate","type":"tags"},{"content":"","date":"2025-10-28","externalUrl":null,"permalink":"/en/tags/kyushu-university/","section":"Tags","summary":"","title":"Kyushu University","type":"tags"},{"content":"","date":"2025-10-28","externalUrl":null,"permalink":"/en/categories/presentation/","section":"Categories","summary":"","title":"Presentation","type":"categories"},{"content":"From October 28 to 29, 2025, the Scintillator Enhancement Workshop 2025 was held at the Ginga Hall, Faculty of Science and Engineering, Iwate University. The workshop is part of Platform A, a KEK detector development project focused on improving scintillators — the light-emitting materials used to detect cosmic rays and other radiation. As part of the workshop, Seiki Tanida, a graduate student at Kyushu University, gave a talk titled \u0026ldquo;Development of 3D-printed scintillators for compact cosmic-ray detectors.\u0026rdquo;\nCompact cosmic-ray detectors like OSECHI need to be low-cost, compact, and easy to build. Since 2023, the team has been 3D-printing their own scintillators.\nTanida reported that the team tuned the printing process (such as how long to expose the resin to UV light) on flat test pieces until they could reliably print shapes matching the design. They also confirmed that their 3D-printed scintillator produces about 60% of the light output of a commercial one — consistent with results from a parallel investigation at Osaka University.\nTanida also identified two remaining challenges: finding ways to further increase the light output, and figuring out why printing failed when the team tried using the same resin again two months later.\nOn the second day, a bear was spotted on the Iwate University campus, and some participants ended up switching to online attendance as a result.\nTalk Details # Title: Development of 3D-printed scintillators for compact cosmic-ray detectors Speaker: Seiki Tanida (Kyushu University) Co-authors: Ren Matsukuma, Keiko Moriyama, Mizuki Yoshioka (Kyushu University), Shota Takami, Kazuki Ueno (Osaka University) Workshop: Scintillator Enhancement Workshop 2025 (Platform A), October 28-29, 2025, Ginga Hall, Faculty of Science and Engineering, Iwate University Link: https://kds.kek.jp/event/56769/ Slides: https://kds.kek.jp/event/56769/contributions/302491/ ","date":"2025-10-28","externalUrl":null,"permalink":"/en/posts/2025/301/","section":"Posts","summary":"From October 28 to 29, 2025, the Scintillator Enhancement Workshop 2025 was held at the Ginga Hall, Faculty of Science and Engineering, Iwate University. The workshop is part of Platform A, a KEK detector development project focused on improving scintillators — the light-emitting materials used to detect cosmic rays and other radiation. As part of the workshop, Seiki Tanida, a graduate student at Kyushu University, gave a talk titled “Development of 3D-printed scintillators for compact cosmic-ray detectors.”\n","title":"We Gave a Talk on OSECHI at the Scintillator Enhancement Workshop 2025","type":"posts"},{"content":"","date":"2025-10-28","externalUrl":null,"permalink":"/tags/%E4%B9%9D%E5%B7%9E%E5%A4%A7%E5%AD%A6/","section":"Tags","summary":"","title":"九州大学","type":"tags"},{"content":"","date":"2025-10-28","externalUrl":null,"permalink":"/tags/%E5%B2%A9%E6%89%8B%E7%9C%8C/","section":"Tags","summary":"","title":"岩手県","type":"tags"},{"content":"On November 16 and 17, 2024, we held an \u0026ldquo;OSECHI Development Retreat\u0026rdquo; at Yamagata University. The OSECHI project normally holds regular meetings online, but about once a year we bring members together in person for a concentrated push on development.\nA key goal of this retreat was to have students actually use \u0026ldquo;haniwers,\u0026rdquo; OSECHI\u0026rsquo;s data acquisition software, hands-on. I had been developing this software on my own up to this point, but having multiple people use it together surfaced unexpected bugs and areas for improvement, giving us valuable feedback for future work.\nWe also tried stacking four OSECHI units together for measurement, verifying operation and data acquisition stability in a multi-unit configuration. This produced important findings on both the hardware and software side.\nBeyond accelerating development, this retreat became a place to discover new challenges through collaboration with students, marking a major step forward for the project going forward.\n","date":"2024-11-16","externalUrl":null,"permalink":"/en/posts/2024/321/","section":"Posts","summary":"On November 16 and 17, 2024, we held an “OSECHI Development Retreat” at Yamagata University. The OSECHI project normally holds regular meetings online, but about once a year we bring members together in person for a concentrated push on development.\nA key goal of this retreat was to have students actually use “haniwers,” OSECHI’s data acquisition software, hands-on. I had been developing this software on my own up to this point, but having multiple people use it together surfaced unexpected bugs and areas for improvement, giving us valuable feedback for future work.\n","title":"We Held a Development Retreat at Yamagata University!","type":"posts"},{"content":"","date":"2024-11-16","externalUrl":null,"permalink":"/en/tags/yamagata-university/","section":"Tags","summary":"","title":"Yamagata University","type":"tags"},{"content":"","date":"2024-11-16","externalUrl":null,"permalink":"/tags/%E5%B1%B1%E5%BD%A2%E5%A4%A7%E5%AD%A6/","section":"Tags","summary":"","title":"山形大学","type":"tags"},{"content":"A proceedings titled \u0026ldquo;墳Q (fun-Q) project: muography of Japanese ancient mounds by high school students\u0026rdquo; was published in Proceedings of Science (PoS).\nThe fun-Q project is muography (muon tomography) of Japanese ancient mounds by high school students, carried out through interdisciplinary collaboration. The team consists of high school students and teachers, scientists, engineers, communicators, curators, and archaeologists. The students are divided into groups, working with experts in both archaeological and physics research and combining the results of their studies. The first target was Akiyama Koshinzuka Kofun, located near the students\u0026rsquo; school. The team conducted a Ground Penetrating Radar (GPR) survey and cosmic-ray measurement using OSECHI, a Japanese-style cosmic-ray muon detector developed for outreach and education.\nProceedings Details # Title: 墳Q (fun-Q) project: muography of Japanese ancient mounds by high school students Authors: M. Ohtsuka, K. Aoki, K. Hashizume, Y. Ishii, T. Ishizawa, S. Kimura, S. Ogata, Y. Okamoto, S. Ono, A. Shiozaki, Y. Takemori, R. Tomiku, W. Yanagimoto, M. Higashide, T. Ishikawa, A. Matsumoto, T. Nakamori, M. Shoji, S. Takahashi, K. Ueno Published in: PoS (Proceedings of the 38th International Cosmic Ray Conference, ICRC2023) Link: https://pos.sissa.it/444/1628/ Related Links # Taking OSECHI Into an Ancient Burial Mound: Cosmic-Ray Research with a High School ","date":"2024-09-28","externalUrl":null,"permalink":"/en/posts/2024/272/","section":"Posts","summary":"A proceedings titled “墳Q (fun-Q) project: muography of Japanese ancient mounds by high school students” was published in Proceedings of Science (PoS).\nThe fun-Q project is muography (muon tomography) of Japanese ancient mounds by high school students, carried out through interdisciplinary collaboration. The team consists of high school students and teachers, scientists, engineers, communicators, curators, and archaeologists. The students are divided into groups, working with experts in both archaeological and physics research and combining the results of their studies. The first target was Akiyama Koshinzuka Kofun, located near the students’ school. The team conducted a Ground Penetrating Radar (GPR) survey and cosmic-ray measurement using OSECHI, a Japanese-style cosmic-ray muon detector developed for outreach and education.\n","title":"Our fun-Q Project Proceedings Published in the ICRC2023 Proceedings","type":"posts"},{"content":"","date":"2024-09-28","externalUrl":null,"permalink":"/en/tags/icrc2023/","section":"Tags","summary":"","title":"ICRC2023","type":"tags"},{"content":"","date":"2024-09-28","externalUrl":null,"permalink":"/en/tags/pos/","section":"Tags","summary":"","title":"PoS","type":"tags"},{"content":"","date":"2024-09-28","externalUrl":null,"permalink":"/en/categories/publication/","section":"Categories","summary":"","title":"Publication","type":"categories"},{"content":"A proceedings titled \u0026ldquo;Development of Japanese-style cosmic-ray muon detector for outreach and education\u0026rdquo; was published in Proceedings of Science (PoS).\nFew citizens or students interested in particle physics and astrophysics have the chance to work with real research equipment such as accelerators, telescopes, and detectors, since these tend to be expensive. Recent technological developments have made it possible to build low-cost detectors, and this proceedings introduces the structure and prototype performance of OSECHI, a low-cost, compact cosmic-ray muon detector, along with examples of its use in outreach.\nProceedings Details # Title: Development of Japanese-style cosmic-ray muon detector for outreach and education Authors: K. Ueno, M. Shoji, M. Higashide, H. Iiyama, T. Ishikawa, T. Kin, A. Matsumoto, T. Nakamori, M. Ohtsuka, S. Takahashi, T. Yoshioka Published in: PoS (Proceedings of the 38th International Cosmic Ray Conference, ICRC2023) Link: https://pos.sissa.it/444/1623/ ","date":"2024-09-27","externalUrl":null,"permalink":"/en/posts/2024/271/","section":"Posts","summary":"A proceedings titled “Development of Japanese-style cosmic-ray muon detector for outreach and education” was published in Proceedings of Science (PoS).\nFew citizens or students interested in particle physics and astrophysics have the chance to work with real research equipment such as accelerators, telescopes, and detectors, since these tend to be expensive. Recent technological developments have made it possible to build low-cost detectors, and this proceedings introduces the structure and prototype performance of OSECHI, a low-cost, compact cosmic-ray muon detector, along with examples of its use in outreach.\n","title":"Our OSECHI Proceedings Published at ICRC2023","type":"posts"},{"content":"On August 17, 2024, the \u0026ldquo;Saji Astro Park Science Program\u0026rdquo; was held at Saji Astro Park in Tottori. As the closing session of a day filled with talks on topics like decarbonization, artificial shooting stars, and X-ray astronomy, a cosmic ray measurement experience titled \u0026ldquo;The Mystery of the Universe! The Wonder of Cosmic Rays\u0026rdquo; was held, led by the OSECHI group as instructors.\nParticipants split into five teams and measured the arrival rate of cosmic rays while changing the detector\u0026rsquo;s angle. After the measurements, each team shared its results with the whole group, and everyone considered why their measured distributions took the shape they did.\nFrom the OSECHI project, Associate Professor Kazuki Ueno (Osaka University), Specially Appointed Assistant Professor Shota Takahashi (Nagoya University), Professor Takeyuki Nakamori (Yamagata University), Professor Satoru Mihara (KEK / SOKENDAI), and graduate students Iiyama and Yaegashi from the Nakamori Lab (Yamagata University) took part.\nRelated Links # Saji Astro Park Science Program event announcement Nakamori Lab, Yamagata University — activity report ","date":"2024-08-17","externalUrl":null,"permalink":"/en/posts/2024/230/","section":"Posts","summary":"On August 17, 2024, the “Saji Astro Park Science Program” was held at Saji Astro Park in Tottori. As the closing session of a day filled with talks on topics like decarbonization, artificial shooting stars, and X-ray astronomy, a cosmic ray measurement experience titled “The Mystery of the Universe! The Wonder of Cosmic Rays” was held, led by the OSECHI group as instructors.\nParticipants split into five teams and measured the arrival rate of cosmic rays while changing the detector’s angle. After the measurements, each team shared its results with the whole group, and everyone considered why their measured distributions took the shape they did.\n","title":"We Held \"The Mystery of the Universe! The Wonder of Cosmic Rays\" Measurement Experience at Saji Astro Park!","type":"posts"},{"content":"","date":"2024-08-17","externalUrl":null,"permalink":"/en/tags/saji-astro-park/","section":"Tags","summary":"","title":"Saji Astro Park","type":"tags"},{"content":"","date":"2024-08-17","externalUrl":null,"permalink":"/en/tags/tottori/","section":"Tags","summary":"","title":"Tottori","type":"tags"},{"content":"","date":"2024-08-17","externalUrl":null,"permalink":"/tags/%E3%81%95%E3%81%98%E3%82%A2%E3%82%B9%E3%83%88%E3%83%AD%E3%83%91%E3%83%BC%E3%82%AF/","section":"Tags","summary":"","title":"さじアストロパーク","type":"tags"},{"content":"","date":"2024-08-17","externalUrl":null,"permalink":"/tags/%E9%B3%A5%E5%8F%96%E7%9C%8C/","section":"Tags","summary":"","title":"鳥取県","type":"tags"},{"content":"","date":"2024-02-17","externalUrl":null,"permalink":"/en/tags/fukuoka/","section":"Tags","summary":"","title":"Fukuoka","type":"tags"},{"content":"","date":"2024-02-17","externalUrl":null,"permalink":"/en/tags/nogake-community-center/","section":"Tags","summary":"","title":"Nogake Community Center","type":"tags"},{"content":"On February 17, 2024, we held the cosmic ray exploration event \u0026ldquo;Tan-Q — The Mystery of the Universe! The Wonder of Cosmic Rays\u0026rdquo; at Nogake Community Center in Fukuoka, as a community outreach program of the Graduate University for Advanced Studies (SOKENDAI). The event let participants from 5th grade up experience hands-on science using OSECHI.\nThe event was held in two parts.\nIn the first part, a seminar, Professor Takeyuki Nakamori of Yamagata University\u0026rsquo;s Faculty of Science spoke about what cosmic rays are.\nIn the second part, a hands-on session, Associate Professor Kazuki Ueno (Osaka University Graduate School of Science) served as instructor, and participants got hands-on with OSECHI to measure invisible cosmic rays.\nRelated Links # SOKENDAI event page ","date":"2024-02-17","externalUrl":null,"permalink":"/en/posts/2024/48/","section":"Posts","summary":"On February 17, 2024, we held the cosmic ray exploration event “Tan-Q — The Mystery of the Universe! The Wonder of Cosmic Rays” at Nogake Community Center in Fukuoka, as a community outreach program of the Graduate University for Advanced Studies (SOKENDAI). The event let participants from 5th grade up experience hands-on science using OSECHI.\nThe event was held in two parts.\nIn the first part, a seminar, Professor Takeyuki Nakamori of Yamagata University’s Faculty of Science spoke about what cosmic rays are.\n","title":"We Held \"Tan-Q — The Mystery of the Universe! The Wonder of Cosmic Rays\" at Nogake Community Center!","type":"posts"},{"content":"","date":"2024-02-17","externalUrl":null,"permalink":"/tags/%E7%A6%8F%E5%B2%A1%E7%9C%8C/","section":"Tags","summary":"","title":"福岡県","type":"tags"},{"content":"","date":"2024-02-17","externalUrl":null,"permalink":"/tags/%E9%87%8E%E8%8A%A5%E5%85%AC%E6%B0%91%E9%A4%A8/","section":"Tags","summary":"","title":"野芥公民館","type":"tags"},{"content":"","date":"2023-08-09","externalUrl":null,"permalink":"/en/categories/activity/","section":"Categories","summary":"","title":"Activity","type":"categories"},{"content":"","date":"2023-08-09","externalUrl":null,"permalink":"/en/tags/akiyama-koshinzuka-kofun/","section":"Tags","summary":"","title":"Akiyama Koshinzuka Kofun","type":"tags"},{"content":"From August 9 to 10, 2023, the OSECHI group teamed up with Waseda University Honjo Senior High School to carry out a measurement study using OSECHI at Akiyama Koshinzuka Kofun, a horizontal-entry round burial mound in Honjo, Saitama Prefecture.\nAkiyama Koshinzuka Kofun is a round burial mound about 34 m in diameter and 5 m high, built in the late 6th century, with a horizontal-entry stone chamber (about 7.7 m long) opening to the south-southwest. It\u0026rsquo;s one of the mounds making up the Akiyama Kofun cluster, designated a Honjo City historic site and a Saitama Prefecture important site, and its internal structure is already known.\nThis time, the group made advance arrangements with Honjo City and was allowed to measure inside. We set up OSECHI inside the mound to verify that the equipment would operate correctly. Taking advantage of OSECHI\u0026rsquo;s portability — a full detector, electronics included, contained in a Japanese-style tiered box — the group took on an overnight measurement inside the unusual environment of the burial mound.\nPartway through the measurement, we observed an unexplained increase in the detection rate, which showed that the circuit design and measurement firmware need to be made more stable. From here, we aim to orient OSECHI toward the entrance side and the far (wall) side of the mound to see whether we can capture a difference in detection rate — using muography, a technique that exploits the high penetrating power of muons produced by cosmic rays to non-destructively determine the amount of material in a given direction by measuring their arrival direction and count through a structure.\nMembers from Waseda University Honjo Senior High School, KEK, Yamagata University, Osaka University, and SOKENDAI gathered for the measurement, with students from Waseda University Honjo observing on site.\nRelated Links # Yamagata University Faculty of Science news article Akiyama Koshinzuka Kofun - Kofun Map (Japanese) City-designated cultural properties - Honjo City (Japanese) ","date":"2023-08-09","externalUrl":null,"permalink":"/en/posts/2023/221/","section":"Posts","summary":"From August 9 to 10, 2023, the OSECHI group teamed up with Waseda University Honjo Senior High School to carry out a measurement study using OSECHI at Akiyama Koshinzuka Kofun, a horizontal-entry round burial mound in Honjo, Saitama Prefecture.\nAkiyama Koshinzuka Kofun is a round burial mound about 34 m in diameter and 5 m high, built in the late 6th century, with a horizontal-entry stone chamber (about 7.7 m long) opening to the south-southwest. It’s one of the mounds making up the Akiyama Kofun cluster, designated a Honjo City historic site and a Saitama Prefecture important site, and its internal structure is already known.\n","title":"Taking OSECHI Into an Ancient Burial Mound: Cosmic-Ray Research with a High School","type":"posts"},{"content":"","date":"2023-08-09","externalUrl":null,"permalink":"/en/tags/saitama/","section":"Tags","summary":"","title":"Saitama","type":"tags"},{"content":"","date":"2023-08-09","externalUrl":null,"permalink":"/tags/%E5%9F%BC%E7%8E%89%E7%9C%8C/","section":"Tags","summary":"","title":"埼玉県","type":"tags"},{"content":"","date":"2023-08-09","externalUrl":null,"permalink":"/tags/%E7%A7%8B%E5%B1%B1%E5%BA%9A%E7%94%B3%E5%A1%9A%E5%8F%A4%E5%A2%B3/","section":"Tags","summary":"","title":"秋山庚申塚古墳","type":"tags"},{"content":"","date":"2023-07-30","externalUrl":null,"permalink":"/en/tags/aichi/","section":"Tags","summary":"","title":"Aichi","type":"tags"},{"content":"On July 30, 2023, the \u0026ldquo;Cosmic Ray Measurement Experience 2023\u0026rdquo; was held at the Kobayashi-Maskawa Institute (KMI), Nagoya University, in Aichi. The event was organized as a public program timed to coincide with the 38th International Cosmic Ray Conference (ICRC2023), which was being held at Nagoya University.\nCo-hosted by KMI and Kasoku Kitchen, the event was open to junior high, high school, and technical college students, who built their own Cosmic Watch and used it to measure cosmic rays.\nDuring the networking session, fellow cosmic-ray outreach groups gathered at ICRC2023 joined in — Kasoku Kitchen, Soramame, Shinshu Cosmic Ray, OSECHI, QuarkNet, and other ICRC2023 attendees interested in outreach — and mingled with the students who had just built their detectors. It was a valuable opportunity to bring together people working on cosmic-ray outreach from around the world.\nRelated Links # Nagoya University Kobayashi-Maskawa Institute event page 38th International Cosmic Ray Conference (ICRC2023) Kasoku Kitchen About Cosmic Watch (Learning Guide) About Soramame (Learning Guide) About Shinshu Cosmic Ray (Learning Guide) About QuarkNet (Learning Guide) ","date":"2023-07-30","externalUrl":null,"permalink":"/en/posts/2023/211/","section":"Posts","summary":"On July 30, 2023, the “Cosmic Ray Measurement Experience 2023” was held at the Kobayashi-Maskawa Institute (KMI), Nagoya University, in Aichi. The event was organized as a public program timed to coincide with the 38th International Cosmic Ray Conference (ICRC2023), which was being held at Nagoya University.\nCo-hosted by KMI and Kasoku Kitchen, the event was open to junior high, high school, and technical college students, who built their own Cosmic Watch and used it to measure cosmic rays.\n","title":"We Held \"Cosmic Ray Measurement Experience 2023\" at Nagoya University!","type":"posts"},{"content":"","date":"2023-07-30","externalUrl":null,"permalink":"/en/tags/nagoya-university/","section":"Tags","summary":"","title":"Nagoya University","type":"tags"},{"content":"","date":"2023-07-30","externalUrl":null,"permalink":"/tags/%E5%90%8D%E5%8F%A4%E5%B1%8B%E5%A4%A7%E5%AD%A6/","section":"Tags","summary":"","title":"名古屋大学","type":"tags"},{"content":"","date":"2023-07-30","externalUrl":null,"permalink":"/tags/%E6%84%9B%E7%9F%A5%E7%9C%8C/","section":"Tags","summary":"","title":"愛知県","type":"tags"},{"content":"On November 6, 2022, Kasoku Kitchen hosted \u0026ldquo;Measure Cosmic Rays with a Cosmic Ray Detector!\u0026rdquo; at the Osaka Science Museum in Osaka. Open to participants from 5th grade through high school, it was a hands-on program where participants built their own Cosmic Watch and used it to observe cosmic rays.\nFrom the OSECHI project, Associate Professor Kazuki Ueno (Osaka University) and Masaki Miyataki took part as staff, helping participants with their builds and introducing the OSECHI project.\nRelated Links # Osaka Science Museum event page Kasoku Kitchen Osaka University Graduate School of Science, Particle Physics (Aoki) Group news article ","date":"2022-11-06","externalUrl":null,"permalink":"/en/posts/2022/310/","section":"Posts","summary":"On November 6, 2022, Kasoku Kitchen hosted “Measure Cosmic Rays with a Cosmic Ray Detector!” at the Osaka Science Museum in Osaka. Open to participants from 5th grade through high school, it was a hands-on program where participants built their own Cosmic Watch and used it to observe cosmic rays.\nFrom the OSECHI project, Associate Professor Kazuki Ueno (Osaka University) and Masaki Miyataki took part as staff, helping participants with their builds and introducing the OSECHI project.\n","title":"We Helped Out at the Osaka Science Museum's \"Measure Cosmic Rays with a Cosmic Ray Detector!\"","type":"posts"},{"content":"","date":"2022-11-06","externalUrl":null,"permalink":"/en/tags/osaka-science-museum/","section":"Tags","summary":"","title":"Osaka Science Museum","type":"tags"},{"content":"","date":"2022-11-06","externalUrl":null,"permalink":"/tags/%E5%A4%A7%E9%98%AA%E5%B8%82%E7%AB%8B%E7%A7%91%E5%AD%A6%E9%A4%A8/","section":"Tags","summary":"","title":"大阪市立科学館","type":"tags"},{"content":"","date":"2020-12-19","externalUrl":null,"permalink":"/en/tags/miraikan/","section":"Tags","summary":"","title":"Miraikan","type":"tags"},{"content":"On December 19, 2020, we held the cosmic ray exploration event \u0026ldquo;Tan-Q — Exploring the Mystery of the Universe Through Cosmic Rays\u0026rdquo; at the National Museum of Emerging Science and Innovation (Miraikan) in Tokyo, as a community outreach program of the Graduate University for Advanced Studies (SOKENDAI). The event let junior high and high school students, teachers, and members of the public experience hands-on science using a small cosmic ray detector.\nThe event was held in two parts.\nIn the first part, a seminar titled \u0026ldquo;Exploring the Mystery of the Universe Through Cosmic Rays,\u0026rdquo; Associate Professor Mizuki Yoshioka of Kyushu University\u0026rsquo;s Research Center for Advanced Particle Physics spoke about what cosmic rays are and introduced cutting-edge research in the field.\nIn the second part, a hands-on session titled \u0026ldquo;The Real Deal!! Let\u0026rsquo;s Catch Cosmic Rays!\u0026rdquo;, Assistant Professor Kazuki Ueno (SOKENDAI / KEK Institute of Particle and Nuclear Studies) served as moderator, and Assistant Professor Masashi Otani (SOKENDAI / KEK Accelerator Laboratory) led the hands-on activity. Participants worked alongside graduate students and early-career researchers, getting hands-on with OSECHI to measure invisible cosmic rays and share their results with each other.\nRelated Links # SOKENDAI event page Event flyer (PDF) ","date":"2020-12-19","externalUrl":null,"permalink":"/en/posts/2020/354/","section":"Posts","summary":"On December 19, 2020, we held the cosmic ray exploration event “Tan-Q — Exploring the Mystery of the Universe Through Cosmic Rays” at the National Museum of Emerging Science and Innovation (Miraikan) in Tokyo, as a community outreach program of the Graduate University for Advanced Studies (SOKENDAI). The event let junior high and high school students, teachers, and members of the public experience hands-on science using a small cosmic ray detector.\n","title":"We Held \"Tan-Q — Exploring the Mystery of the Universe Through Cosmic Rays\" at the Miraikan!","type":"posts"},{"content":"","date":"2020-12-19","externalUrl":null,"permalink":"/en/tags/tokyo/","section":"Tags","summary":"","title":"Tokyo","type":"tags"},{"content":"","date":"2020-12-19","externalUrl":null,"permalink":"/tags/%E6%97%A5%E6%9C%AC%E7%A7%91%E5%AD%A6%E6%9C%AA%E6%9D%A5%E9%A4%A8/","section":"Tags","summary":"","title":"日本科学未来館","type":"tags"},{"content":"","date":"2020-12-19","externalUrl":null,"permalink":"/tags/%E6%9D%B1%E4%BA%AC%E9%83%BD/","section":"Tags","summary":"","title":"東京都","type":"tags"},{"content":"","date":"2020-01-13","externalUrl":null,"permalink":"/en/tags/hiroo-gakuen/","section":"Tags","summary":"","title":"Hiroo Gakuen","type":"tags"},{"content":"On January 13, 2020, we held the cosmic ray exploration workshop \u0026ldquo;Tan-Q\u0026rdquo; at Hiroo Gakuen Junior and Senior High School in Tokyo, together with junior high and high school students from across the country, doing a hands-on cosmic ray measurement exercise using cosmic ray detectors.\nParticipants split into four teams and measured how the rate of cosmic rays reaching a detector changed between the upper floors of a building and ground level.\nAfter the exercise, students from Waseda University Honjo Senior High School and Hiroo Gakuen High School — both already active in cosmic ray exploration — gave presentations about their activities.\nAssistant Professor Kazuki Ueno of KEK\u0026rsquo;s Institute of Particle and Nuclear Studies then introduced OSECHI, a cosmic ray detector built by repurposing an actual jubako (a traditional Japanese tiered lacquer box). Everyone in attendance was surprised and intrigued to see such an unexpected everyday item become a tool for research.\nThe workshop closed with a session connecting participants with researchers who had traveled from abroad. Kenn, the representative of QuarkNet — an outreach program run mainly in the United States — gave an introduction to the program.\nFeedback from the post-workshop participant survey included comments like, \u0026ldquo;I was surprised that even high school students could connect with university professors and go this deep into research!\u0026rdquo; and \u0026ldquo;I got to experience something I normally never would — it was fun, and I\u0026rsquo;d love to join again.\u0026rdquo;\nRelated Links # KEK Institute of Particle and Nuclear Studies news article QuarkNet ","date":"2020-01-13","externalUrl":null,"permalink":"/en/posts/2020/13/","section":"Posts","summary":"On January 13, 2020, we held the cosmic ray exploration workshop “Tan-Q” at Hiroo Gakuen Junior and Senior High School in Tokyo, together with junior high and high school students from across the country, doing a hands-on cosmic ray measurement exercise using cosmic ray detectors.\nParticipants split into four teams and measured how the rate of cosmic rays reaching a detector changed between the upper floors of a building and ground level.\n","title":"We Held a Cosmic Ray Exploration Workshop \"Tan-Q\" at Hiroo Gakuen!","type":"posts"},{"content":"","date":"2020-01-13","externalUrl":null,"permalink":"/tags/%E5%BA%83%E5%B0%BE%E5%AD%A6%E5%9C%92/","section":"Tags","summary":"","title":"広尾学園","type":"tags"},{"content":"On October 5, 2019, we held the cosmic ray observation event \u0026ldquo;Invisible Cosmic Rays See Everything! — Experience Cutting-Edge Particle and Astrophysics —\u0026rdquo; at S-BIRD, a hub for industrial promotion and talent development in Iida City, Nagano Prefecture. The event was open to junior high, high school, and technical college students nationwide, and included an activity presentation by students from Hiroo Gakuen High School.\nThe event was held in two parts.\nIn the first part, Professor Emeritus Masaki Fukushima of the University of Tokyo, of the Telescope Array project, gave a seminar titled \u0026ldquo;Unraveling the Mystery of Ultra-High-Energy Cosmic Rays.\u0026rdquo; The talk covered a wide range of topics, from the history of the discovery of radiation and cosmic rays to cutting-edge research on ultra-high-energy cosmic rays.\nIn the second part, participants used detectors they had built themselves to carry out a hands-on measurement experiment. They got to see for themselves how the rate of \u0026ldquo;secondary cosmic rays\u0026rdquo; reaching the ground changes depending on the angle at which the detector is pointed.\nGoing from a seminar on cutting-edge research to operating a detector and taking measurements with their own hands, we hope the experience made the phenomenon of cosmic rays feel a little more real to the participants. We look forward to holding more outreach events like this one in other locations going forward.\nRelated Links # S-BIRD (Minami-Shinshu / Iida Industry Center) Telescope Array Experiment Website KEK Institute of Particle and Nuclear Studies news article ","date":"2019-10-05","externalUrl":null,"permalink":"/en/posts/2019/278/","section":"Posts","summary":"On October 5, 2019, we held the cosmic ray observation event “Invisible Cosmic Rays See Everything! — Experience Cutting-Edge Particle and Astrophysics —” at S-BIRD, a hub for industrial promotion and talent development in Iida City, Nagano Prefecture. The event was open to junior high, high school, and technical college students nationwide, and included an activity presentation by students from Hiroo Gakuen High School.\nThe event was held in two parts.\n","title":"We Held a Cosmic Ray Observation Event at S-BIRD in Nagano!","type":"posts"},{"content":"","date":"2019-10-05","externalUrl":null,"permalink":"/en/tags/nagano/","section":"Tags","summary":"","title":"Nagano","type":"tags"},{"content":"","date":"2019-10-05","externalUrl":null,"permalink":"/en/tags/s-bird/","section":"Tags","summary":"","title":"S-BIRD","type":"tags"},{"content":"","date":"2019-10-05","externalUrl":null,"permalink":"/tags/%E3%82%A8%E3%82%B9%E3%83%90%E3%83%BC%E3%83%89/","section":"Tags","summary":"","title":"エス・バード","type":"tags"},{"content":"","date":"2019-10-05","externalUrl":null,"permalink":"/tags/%E9%95%B7%E9%87%8E%E7%9C%8C/","section":"Tags","summary":"","title":"長野県","type":"tags"},{"content":" About OSECHI # Outreach and Science Education Cosmic Hunting Instrument\nOSECHI is a project dedicated to advancing cosmic research and science education.\nOur Vision # Operate a measurement instrument with your own hands, and use it to measure cosmic rays yourself. We want to bring that experience to more people. See Our Vision for more details.\nOur Team # The OSECHI community is run by a few roles working together, depending on the scope of activity and responsibility.\nCore members — Lead the launch and operation of the project and help decide its direction Development team — Support the technical foundation, including detector design and software development User group — Support the community\u0026rsquo;s growth through measurement, educational activities, and workshops These roles can overlap depending on the activity. See the list of participating institutes for details.\nGet Involved # To keep a safe and comfortable environment for everyone, the OSECHI community currently uses a referral-based system for joining. At the same time, we want to remain a community that anyone can join. There is no cost to join the community (equipment and development costs are self-funded). You\u0026rsquo;re free to get involved online or offline.\nOur approach to activities, along with a few requests, is summarized in the Community and Participation Guidelines.\nIf you\u0026rsquo;re interested in joining or supporting OSECHI, please contact us.\n","externalUrl":null,"permalink":"/en/about/","section":"About OSECHI","summary":"About OSECHI # Outreach and Science Education Cosmic Hunting Instrument\nOSECHI is a project dedicated to advancing cosmic research and science education.\nOur Vision # Operate a measurement instrument with your own hands, and use it to measure cosmic rays yourself. We want to bring that experience to more people. See Our Vision for more details.\n","title":"About OSECHI","type":"about"},{"content":"","externalUrl":null,"permalink":"/en/roles/core/","section":"Roles","summary":"","title":"Core","type":"roles"},{"content":"","externalUrl":null,"permalink":"/en/roles/dev/","section":"Roles","summary":"","title":"Dev","type":"roles"},{"content":"A guide for members who lead the core development of OSECHI — circuit design, software debugging, and more. Written so that even someone newly assigned to the project can get started with confidence, it covers how to approach hardware, software, and data sharing work.\n","externalUrl":null,"permalink":"/en/developer-guide/","section":"Developer Guide","summary":"A guide for members who lead the core development of OSECHI — circuit design, software debugging, and more. Written so that even someone newly assigned to the project can get started with confidence, it covers how to approach hardware, software, and data sharing work.\n","title":"Developer Guide","type":"developer-guide"},{"content":"","externalUrl":null,"permalink":"/en/tags/ehime/","section":"Tags","summary":"","title":"Ehime","type":"tags"},{"content":"","externalUrl":null,"permalink":"/en/series/explore-the-frontier/","section":"Series","summary":"","title":"Explore the Frontier","type":"series"},{"content":"","externalUrl":null,"permalink":"/en/series/explore-the-muon-frontier/","section":"Series","summary":"","title":"Explore the Muon Frontier","type":"series"},{"content":"Welcome to the OSECHI community.\nCommunity members support the project by sharing feedback, observations, and issues from their experience using OSECHI. No programming knowledge is required. Information is shared via Discord.\n","externalUrl":null,"permalink":"/en/guidelines/","section":"Guidelines","summary":"Welcome to the OSECHI community.\nCommunity members support the project by sharing feedback, observations, and issues from their experience using OSECHI. No programming knowledge is required. Information is shared via Discord.\n","title":"Guidelines","type":"guidelines"},{"content":"","externalUrl":null,"permalink":"/en/tags/ibaraki/","section":"Tags","summary":"","title":"Ibaraki","type":"tags"},{"content":"","externalUrl":null,"permalink":"/en/tags/kanagawa/","section":"Tags","summary":"","title":"Kanagawa","type":"tags"},{"content":"","externalUrl":null,"permalink":"/en/series/learn-about-cosmic-rays/","section":"Series","summary":"","title":"Learn About Cosmic Rays","type":"series"},{"content":"\u0026ldquo;What can OSECHI actually measure?\u0026rdquo; \u0026ldquo;What can I learn by using it?\u0026rdquo; If that\u0026rsquo;s what brought you here, start with this page on cosmic rays.\nFrom the basics of what cosmic rays are, to how a detector actually senses them, to the research frontier still being explored around the world today, we\u0026rsquo;ve organized it so you can read through one step at a time.\nIf any of this sparks your interest, come do OSECHI with us!\n","externalUrl":null,"permalink":"/en/learn/","section":"Learning Guide","summary":"“What can OSECHI actually measure?” “What can I learn by using it?” If that’s what brought you here, start with this page on cosmic rays.\nFrom the basics of what cosmic rays are, to how a detector actually senses them, to the research frontier still being explored around the world today, we’ve organized it so you can read through one step at a time.\nIf any of this sparks your interest, come do OSECHI with us!\n","title":"Learning Guide","type":"learn"},{"content":"","externalUrl":null,"permalink":"/en/series/measure-cosmic-rays/","section":"Series","summary":"","title":"Measure Cosmic Rays","type":"series"},{"content":"Members of the OSECHI project.\n","externalUrl":null,"permalink":"/en/members/","section":"Members","summary":"Members of the OSECHI project.\n","title":"Members","type":"members"},{"content":"","externalUrl":null,"permalink":"/en/tags/miyazaki/","section":"Tags","summary":"","title":"Miyazaki","type":"tags"},{"content":"","externalUrl":null,"permalink":"/en/tags/oita/","section":"Tags","summary":"","title":"Oita","type":"tags"},{"content":"A guide for teachers and science museum staff who want to use OSECHI in lessons and events.\n","externalUrl":null,"permalink":"/en/organizer-guide/","section":"Organizer Guide","summary":"A guide for teachers and science museum staff who want to use OSECHI in lessons and events.\n","title":"Organizer Guide","type":"organizer-guide"},{"content":"Universities and research institutes where OSECHI members are based.\n","externalUrl":null,"permalink":"/en/institutions/","section":"Participating Institutes","summary":"Universities and research institutes where OSECHI members are based.\n","title":"Participating Institutes","type":"institutions"},{"content":"","externalUrl":null,"permalink":"/en/roles/","section":"Roles","summary":"","title":"Roles","type":"roles"},{"content":"","externalUrl":null,"permalink":"/en/series/","section":"Series","summary":"","title":"Series","type":"series"},{"content":"A guide for those who want to measure cosmic rays and muons using OSECHI.\n","externalUrl":null,"permalink":"/en/user-guide/","section":"User Guide","summary":"A guide for those who want to measure cosmic rays and muons using OSECHI.\n","title":"User Guide","type":"user-guide"},{"content":"","externalUrl":null,"permalink":"/en/tags/yamagata/","section":"Tags","summary":"","title":"Yamagata","type":"tags"},{"content":"","externalUrl":null,"permalink":"/series/%E3%83%9F%E3%83%A5%E3%83%BC%E3%82%AA%E3%83%B3%E3%81%AE%E6%9C%80%E5%89%8D%E7%B7%9A%E3%82%92%E7%9F%A5%E3%82%8B/","section":"Series","summary":"","title":"ミューオンの最前線を知る","type":"series"},{"content":"","externalUrl":null,"permalink":"/tags/%E5%A4%A7%E5%88%86%E7%9C%8C/","section":"Tags","summary":"","title":"大分県","type":"tags"},{"content":"","externalUrl":null,"permalink":"/series/%E5%AE%87%E5%AE%99%E7%B7%9A%E3%81%AE%E6%9C%80%E5%89%8D%E7%B7%9A%E3%82%92%E7%9F%A5%E3%82%8B/","section":"Series","summary":"","title":"宇宙線の最前線を知る","type":"series"},{"content":"","externalUrl":null,"permalink":"/series/%E5%AE%87%E5%AE%99%E7%B7%9A%E3%82%92%E6%B8%AC%E3%82%8B/","section":"Series","summary":"","title":"宇宙線を測る","type":"series"},{"content":"","externalUrl":null,"permalink":"/series/%E5%AE%87%E5%AE%99%E7%B7%9A%E3%82%92%E7%9F%A5%E3%82%8B/","section":"Series","summary":"","title":"宇宙線を知る","type":"series"},{"content":"","externalUrl":null,"permalink":"/tags/%E5%AE%AE%E5%B4%8E%E7%9C%8C/","section":"Tags","summary":"","title":"宮崎県","type":"tags"},{"content":"","externalUrl":null,"permalink":"/tags/%E5%B1%B1%E5%BD%A2%E7%9C%8C/","section":"Tags","summary":"","title":"山形県","type":"tags"},{"content":"","externalUrl":null,"permalink":"/tags/%E6%84%9B%E5%AA%9B%E7%9C%8C/","section":"Tags","summary":"","title":"愛媛県","type":"tags"},{"content":"","externalUrl":null,"permalink":"/tags/%E7%A5%9E%E5%A5%88%E5%B7%9D%E7%9C%8C/","section":"Tags","summary":"","title":"神奈川県","type":"tags"},{"content":"","externalUrl":null,"permalink":"/tags/%E8%8C%A8%E5%9F%8E%E7%9C%8C/","section":"Tags","summary":"","title":"茨城県","type":"tags"}]