The document describes the Fluorescence technique - FAST (Fluorescence detector Array of Single-pixel Telescopes) which aims to detect ultrahigh-energy cosmic rays, neutrino and gamma rays using a low-cost approach. It involves using smaller optics and single or few pixel cameras in an array of telescopes to cover a large target volume in a more affordable way than with large fluorescence detectors. Simulations show that a 40 EeV air shower can be detected by a 20 km FAST telescope. Field measurements have validated the FAST concept by detecting air showers and lasers. An automated all-sky camera has also been installed to monitor atmospheric conditions.
Observing ultra-high energy cosmic rays with prototypes of the Fluorescence d...Toshihiro FUJII
1. The document describes observations of ultra-high energy cosmic rays using prototypes of the Fluorescence detector Array of Single-pixel Telescopes (FAST) project in both hemispheres.
2. FAST aims to observe cosmic rays with energies over 10^20 eV using an array of low-cost telescopes to cover a large ground area.
3. Initial results are presented from FAST prototypes installed at the Telescope Array site, including coincident observations of air showers with the Telescope Array fluorescence detector and reconstruction of shower parameters from FAST data.
The document summarizes the FAST (Fluorescence detector Array of Single-pixel Telescopes) project, which aims to detect ultra-high energy cosmic rays and neutral particles. FAST proposes an array of single-pixel telescopes with simple optics and cameras to cover a large target area more cost-effectively than existing fluorescence detectors. Each FAST telescope would have a 1m2 mirror, four photomultiplier tubes, and a 30°x30° field of view. An array of 500 stations with 12 telescopes each could achieve coverage of 150,000 km2. Initial observations with three FAST telescopes have detected air shower signals in coincidence with an existing fluorescence detector.
A next-generation ground array for the detection of ultrahigh-energy cosmic r...Toshihiro FUJII
This document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST), a proposed next-generation ground array for detecting ultrahigh-energy cosmic rays. FAST would consist of hundreds of small telescopes, each with a single or few pixel camera, covering a large ground area. This design aims to significantly increase the detection of cosmic rays above 57 EeV and 100 EeV compared to current experiments like the Telescope Array and Pierre Auger Observatory, enabling new insights into the origin and nature of the highest energy cosmic rays. Prototypes of FAST telescopes have been constructed and tested. The proposed full FAST array would cover over 150,000 km2 with 500 stations, detecting over 5000 cosmic rays above 57 EeV
The document describes the Fluorescence technique - FAST (Fluorescence detector Array of Single-pixel Telescopes) which aims to detect ultrahigh-energy cosmic rays, neutrino and gamma rays using a low-cost approach. It involves using smaller optics and single or few pixel cameras in an array of telescopes to cover a large target volume in a more affordable way than with large fluorescence detectors. Simulations show that a 40 EeV air shower can be detected by a 20 km FAST telescope. Field measurements have validated the FAST concept by detecting air showers and lasers. An automated all-sky camera has also been installed to monitor atmospheric conditions.
Observing ultra-high energy cosmic rays with prototypes of the Fluorescence d...Toshihiro FUJII
1. The document describes observations of ultra-high energy cosmic rays using prototypes of the Fluorescence detector Array of Single-pixel Telescopes (FAST) project in both hemispheres.
2. FAST aims to observe cosmic rays with energies over 10^20 eV using an array of low-cost telescopes to cover a large ground area.
3. Initial results are presented from FAST prototypes installed at the Telescope Array site, including coincident observations of air showers with the Telescope Array fluorescence detector and reconstruction of shower parameters from FAST data.
The document summarizes the FAST (Fluorescence detector Array of Single-pixel Telescopes) project, which aims to detect ultra-high energy cosmic rays and neutral particles. FAST proposes an array of single-pixel telescopes with simple optics and cameras to cover a large target area more cost-effectively than existing fluorescence detectors. Each FAST telescope would have a 1m2 mirror, four photomultiplier tubes, and a 30°x30° field of view. An array of 500 stations with 12 telescopes each could achieve coverage of 150,000 km2. Initial observations with three FAST telescopes have detected air shower signals in coincidence with an existing fluorescence detector.
A next-generation ground array for the detection of ultrahigh-energy cosmic r...Toshihiro FUJII
This document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST), a proposed next-generation ground array for detecting ultrahigh-energy cosmic rays. FAST would consist of hundreds of small telescopes, each with a single or few pixel camera, covering a large ground area. This design aims to significantly increase the detection of cosmic rays above 57 EeV and 100 EeV compared to current experiments like the Telescope Array and Pierre Auger Observatory, enabling new insights into the origin and nature of the highest energy cosmic rays. Prototypes of FAST telescopes have been constructed and tested. The proposed full FAST array would cover over 150,000 km2 with 500 stations, detecting over 5000 cosmic rays above 57 EeV
Atmospheric monitoring with the Fluorescence detector Array of Single-pixel T...Toshihiro FUJII
1) The document describes the Atmospheric monitoring with the Fluorescence detector Array of Single-pixel Telescopes (FAST) project.
2) FAST uses arrays of low-cost single pixel telescopes to detect ultrahigh energy cosmic rays and aims to observe over 400 hours.
3) Atmospheric monitoring instruments including the FAST All Sky Camera (FASCam), Sky Quality Monitor (SQM), and laser shots from the Telescope Array's Central Laser Facility are used to characterize cloud coverage and the night sky background.
The document describes the FAST (Fluorescence detector Array of Single-pixel Telescopes) project. FAST aims to measure ultra-high energy cosmic rays above 1019.5 eV using an array of single-pixel telescopes to detect air fluorescence. Each FAST station would have 12 telescopes covering a 30°×360° field of view. With 500 stations spaced 20 km apart over 150,000 km2, FAST could detect over 5,000 events per year above 57 EeV and 650 above 100 EeV. Prototype FAST telescopes have been installed and observed laser shots and cosmic ray air showers in coincidences with the Telescope Array fluorescence detector.
Future ground arrays for ultrahigh-energy cosmic rays: recent updates and per...Toshihiro FUJII
The document summarizes recent updates on future ground-based arrays for detecting ultra-high energy cosmic rays. It discusses key findings from UHECR observations including the energy spectrum measured by the Telescope Array and Pierre Auger Observatory experiments. There is good agreement between the two experiments within systematic uncertainties, though the second break point in the energy spectrum occurs at a slightly higher energy for TA. It also summarizes mass composition results from Xmax distributions, finding the data is best described by a mix of light and intermediate mass nuclei. No significant photons or neutrinos have been detected at the highest energies that would be expected from the GZK effect.
This document summarizes the results of a 7-year study by the Telescope Array experiment measuring ultra-high energy cosmic rays. Key findings include:
- Over 7 years, 28,269 shower candidates above 1017.2 eV were observed. The energy spectrum follows a power law up to the ankle at 1018.62 eV.
- The average depth of shower maximum (Xmax) was measured in different energy ranges and found to be consistent with lighter compositions such as protons or mixed light and heavy nuclei.
- The flux and energy spectrum measured by Telescope Array is consistent with previous measurements by the HiRes and Auger experiments, helping to improve our understanding of ultra-high energy cosmic rays.
The document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST) project. Some key points:
- FAST will consist of an array of single-pixel telescopes to detect ultra-high energy cosmic rays via fluorescence technique.
- A prototype was constructed and tested in 2015-2017. Data was collected at the Telescope Array site over 21 km and compared to simulations.
- The project aims to build a larger array with more telescopes that could achieve 4 times the exposure of the Telescope Array or 10 times that of the Pierre Auger Observatory. This would allow studies of cosmic rays above 10^19.5 eV.
- An update on the project's progress in design
First results from the full-scale prototype for the Fluorescence detector Arr...Toshihiro FUJII
The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design concept for the next generation of ultrahigh-energy cosmic ray (UHECR) observatories, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of the highest energy cosmic rays. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. Motivated by the successful detection of UHECRs using a prototype comprised of a single 200 mm photomultiplier-tube and a 1 m2 Fresnel lens system [Astropart.Phys. 74 (2016) 64-72], we have developed a new full-scale prototype consisting of four 200 mm photomultiplier-tubes at the focus of a segmented mirror of 1.6 m in diameter. In October 2016 we installed the full-scale prototype at the Telescope Array site in central Utah, USA, and began steady data taking. We report on first results of the full-scale FAST prototype, including measurements of artificial light sources, distant ultraviolet lasers, and UHECRs.
35th International Cosmic Ray Conference — ICRC2017 18th July, 2017
Bexco, Busan, Korea
The document describes the progress of the Fluorescence detector Array of Single-pixel Telescopes (FAST) project between October 2016 and January 2017. Key points include successful detection of 128 air shower events above 18 PeV, an energy threshold 21 km from the telescope, and plans to upgrade the data acquisition system to include GPS timing in June 2017.
The document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST) project. FAST aims to build an array of low-cost single-pixel fluorescence detectors spaced over large areas to study ultra-high energy cosmic rays (UHECR). Each FAST station would have 12 telescopes with 4 PMTs each, covering a 30°x360° field of view. An array of 500 stations over 150,000 km2 could achieve an exposure over 12 times that of the Pierre Auger Observatory. Simulations show FAST may achieve 10% energy resolution and 35 g/cm2 Xmax resolution for cosmic rays above 1019.5 eV. The full-scale FAST prototype has been constructed and work is ongoing to develop
The FAST Project - Next Generation UHECR Observatory -Toshihiro FUJII
The FAST project aims to build a next generation ultra-high energy cosmic ray observatory consisting of an array of single-pixel telescopes called FAST (Fluorescence detector Array of Single-pixel Telescopes). Each telescope would have a 1 square meter aperture and camera with 4 photomultiplier tubes covering a 30x30 degree field of view. An array of 500 such telescopes spaced 20 km apart could cover an area of 150,000 square km. This would provide over 10 times the exposure of the Telescope Array and allow for precision measurements of UHECR spectrum and mass composition above 10^19.5 eV as well as searches for ultra-high energy photons and neutrinos. A full-scale FAST prototype
1) The document discusses future prospects for ultra-high energy cosmic rays (UHECR) and ultra-high energy photons, including expanding the coverage of existing observatories like TA and Auger, developing new detectors with improved mass composition sensitivity and photon/hadron separation, and pioneering space-based UHECR detection with missions like JEM-EUSO and FAST.
2) It proposes a novel fluorescence detector concept called FAST that would deploy hundreds of single-pixel telescope stations over 150,000 km2 to study UHECR above 1019.5 eV with over an order of magnitude more exposure than current ground arrays.
3) Near-term opportunities discussed include using the EUSO-TA
1. The document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST) project, which aims to develop an economical fluorescence detector array to detect ultra-high energy cosmic rays and neutral particles.
2. A full-scale FAST prototype is being constructed and tested. It is expected to be installed at the Telescope Array experiment site in Utah in June 2016 to perform calibration and cross-checks with the existing detectors.
3. Preliminary simulations show that the combined analysis of data from FAST and the surface detector array could provide an energy resolution of 10% and an Xmax resolution of 35 g/cm2 for protons at 10^19.5 eV.
Next-Generation Observatory: Fluorescence detector Array of Single Pixel Tele...Toshihiro FUJII
The document describes the proposed FAST (Fluorescence detector Array of Single-pixel Telescopes) concept for a next-generation ultra-high energy cosmic ray observatory. FAST would consist of 500 single-pixel telescope stations spaced 20 km apart, covering an area of 150,000 km2. Each station would have 12 telescopes with 48 photomultiplier tubes providing 360 degree coverage. This would provide over 10 times the exposure of current observatories like the Telescope Array and Pierre Auger Observatory. An initial prototype was successfully tested at the Telescope Array site in 2014, detecting air shower signals in coincidence with the Telescope Array fluorescence detector. Further R&D and construction of a full-scale FAST prototype is planned
A Conceptual Design for a Large Ground Array of Fluorescence DetectorsToshihiro FUJII
This document proposes a conceptual design for a large ground array of fluorescence detectors to study ultra-high energy cosmic rays. The design envisions an array covering over 40,000 km2 using a simplified fluorescence detector telescope with a single, large pixel and fresnel lens. It could achieve the same statistics as the Pierre Auger Observatory above 1019.5 eV but at a much lower cost by reducing the number of photomultiplier tubes and electronics. First simulations show the design could efficiently trigger on air showers using timing from three stations spaced 20 km apart with no surface detector required. The document calls for further R&D to develop this concept into a workable design for the next generation ultra-high energy cosmic ray observatory
Development of a prototype for Fluorescence detector Array of Single-pixel Te...Toshihiro FUJII
This document summarizes the results from the first field test of the Fluorescence detector Array of Single-pixel Telescopes (FAST) concept. The test involved a single FAST telescope prototype installed at the Telescope Array site in Utah. Key results included stable operation under night sky backgrounds, detection of laser shots and air shower signals consistent with expectations, and a successful collaboration between the Pierre Auger, Telescope Array and JEM-EUSO experiments. Future plans involve developing a full 30x30 degree prototype to further validate the FAST concept.
First results from a prototype for the Fluorescence detector Array of Single-...Toshihiro FUJII
The document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST) concept for observing ultra-high energy cosmic rays. The FAST prototype was tested using the EUSO-TA telescope and detected laser shots and 16 air shower candidates in coincidence with the Telescope Array fluorescence detector. A new FAST prototype is being constructed to establish its sensitivity and detect air shower profiles including the depth of shower maximum. The document outlines future plans to install FAST at the Pierre Auger Observatory and Telescope Array for cross-calibration and to independently measure energy and air shower maximum between the two experiments using a low-cost simplified fluorescence detector design.
Fluorescence detector Array of Single-pixel Telescopes (FAST) projectToshihiro FUJII
This document discusses the history and development of fluorescence detection techniques for ultra-high energy cosmic rays (UHECR). It proposes a new concept called the Fluorescence detector Array of Single-pixel Telescopes (FAST) project. FAST aims to develop an optimized and economical fluorescence detector array to observe UHECRs above 1019.5 eV over a large area. The document outlines the design of FAST stations and reports on an initial test using the EUSO-TA prototype that successfully detected laser pulses and UHECR signals. It concludes by discussing plans to construct a new full-scale FAST prototype and the potential for FAST to increase UHECR exposure and help resolve questions about their origin.
This document summarizes the results from field testing a prototype Fast Array of Single-Pixel Telescopes (FAST) for ultra-high energy cosmic ray detection. Key findings include:
1) The FAST prototype operated very stably and detected laser shots and air shower candidates consistent with expectations.
2) Reconstructed air shower maximum depths from FAST data alone could achieve 30 g/cm^2 resolution for energies above 10^19.5 eV.
3) Future improvements to the FAST design were identified, and a full 30°×30° prototype is the next step.
Atmospheric monitoring with the Fluorescence detector Array of Single-pixel T...Toshihiro FUJII
1) The document describes the Atmospheric monitoring with the Fluorescence detector Array of Single-pixel Telescopes (FAST) project.
2) FAST uses arrays of low-cost single pixel telescopes to detect ultrahigh energy cosmic rays and aims to observe over 400 hours.
3) Atmospheric monitoring instruments including the FAST All Sky Camera (FASCam), Sky Quality Monitor (SQM), and laser shots from the Telescope Array's Central Laser Facility are used to characterize cloud coverage and the night sky background.
The document describes the FAST (Fluorescence detector Array of Single-pixel Telescopes) project. FAST aims to measure ultra-high energy cosmic rays above 1019.5 eV using an array of single-pixel telescopes to detect air fluorescence. Each FAST station would have 12 telescopes covering a 30°×360° field of view. With 500 stations spaced 20 km apart over 150,000 km2, FAST could detect over 5,000 events per year above 57 EeV and 650 above 100 EeV. Prototype FAST telescopes have been installed and observed laser shots and cosmic ray air showers in coincidences with the Telescope Array fluorescence detector.
Future ground arrays for ultrahigh-energy cosmic rays: recent updates and per...Toshihiro FUJII
The document summarizes recent updates on future ground-based arrays for detecting ultra-high energy cosmic rays. It discusses key findings from UHECR observations including the energy spectrum measured by the Telescope Array and Pierre Auger Observatory experiments. There is good agreement between the two experiments within systematic uncertainties, though the second break point in the energy spectrum occurs at a slightly higher energy for TA. It also summarizes mass composition results from Xmax distributions, finding the data is best described by a mix of light and intermediate mass nuclei. No significant photons or neutrinos have been detected at the highest energies that would be expected from the GZK effect.
This document summarizes the results of a 7-year study by the Telescope Array experiment measuring ultra-high energy cosmic rays. Key findings include:
- Over 7 years, 28,269 shower candidates above 1017.2 eV were observed. The energy spectrum follows a power law up to the ankle at 1018.62 eV.
- The average depth of shower maximum (Xmax) was measured in different energy ranges and found to be consistent with lighter compositions such as protons or mixed light and heavy nuclei.
- The flux and energy spectrum measured by Telescope Array is consistent with previous measurements by the HiRes and Auger experiments, helping to improve our understanding of ultra-high energy cosmic rays.
The document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST) project. Some key points:
- FAST will consist of an array of single-pixel telescopes to detect ultra-high energy cosmic rays via fluorescence technique.
- A prototype was constructed and tested in 2015-2017. Data was collected at the Telescope Array site over 21 km and compared to simulations.
- The project aims to build a larger array with more telescopes that could achieve 4 times the exposure of the Telescope Array or 10 times that of the Pierre Auger Observatory. This would allow studies of cosmic rays above 10^19.5 eV.
- An update on the project's progress in design
First results from the full-scale prototype for the Fluorescence detector Arr...Toshihiro FUJII
The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design concept for the next generation of ultrahigh-energy cosmic ray (UHECR) observatories, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of the highest energy cosmic rays. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. Motivated by the successful detection of UHECRs using a prototype comprised of a single 200 mm photomultiplier-tube and a 1 m2 Fresnel lens system [Astropart.Phys. 74 (2016) 64-72], we have developed a new full-scale prototype consisting of four 200 mm photomultiplier-tubes at the focus of a segmented mirror of 1.6 m in diameter. In October 2016 we installed the full-scale prototype at the Telescope Array site in central Utah, USA, and began steady data taking. We report on first results of the full-scale FAST prototype, including measurements of artificial light sources, distant ultraviolet lasers, and UHECRs.
35th International Cosmic Ray Conference — ICRC2017 18th July, 2017
Bexco, Busan, Korea
The document describes the progress of the Fluorescence detector Array of Single-pixel Telescopes (FAST) project between October 2016 and January 2017. Key points include successful detection of 128 air shower events above 18 PeV, an energy threshold 21 km from the telescope, and plans to upgrade the data acquisition system to include GPS timing in June 2017.
The document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST) project. FAST aims to build an array of low-cost single-pixel fluorescence detectors spaced over large areas to study ultra-high energy cosmic rays (UHECR). Each FAST station would have 12 telescopes with 4 PMTs each, covering a 30°x360° field of view. An array of 500 stations over 150,000 km2 could achieve an exposure over 12 times that of the Pierre Auger Observatory. Simulations show FAST may achieve 10% energy resolution and 35 g/cm2 Xmax resolution for cosmic rays above 1019.5 eV. The full-scale FAST prototype has been constructed and work is ongoing to develop
The FAST Project - Next Generation UHECR Observatory -Toshihiro FUJII
The FAST project aims to build a next generation ultra-high energy cosmic ray observatory consisting of an array of single-pixel telescopes called FAST (Fluorescence detector Array of Single-pixel Telescopes). Each telescope would have a 1 square meter aperture and camera with 4 photomultiplier tubes covering a 30x30 degree field of view. An array of 500 such telescopes spaced 20 km apart could cover an area of 150,000 square km. This would provide over 10 times the exposure of the Telescope Array and allow for precision measurements of UHECR spectrum and mass composition above 10^19.5 eV as well as searches for ultra-high energy photons and neutrinos. A full-scale FAST prototype
1) The document discusses future prospects for ultra-high energy cosmic rays (UHECR) and ultra-high energy photons, including expanding the coverage of existing observatories like TA and Auger, developing new detectors with improved mass composition sensitivity and photon/hadron separation, and pioneering space-based UHECR detection with missions like JEM-EUSO and FAST.
2) It proposes a novel fluorescence detector concept called FAST that would deploy hundreds of single-pixel telescope stations over 150,000 km2 to study UHECR above 1019.5 eV with over an order of magnitude more exposure than current ground arrays.
3) Near-term opportunities discussed include using the EUSO-TA
1. The document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST) project, which aims to develop an economical fluorescence detector array to detect ultra-high energy cosmic rays and neutral particles.
2. A full-scale FAST prototype is being constructed and tested. It is expected to be installed at the Telescope Array experiment site in Utah in June 2016 to perform calibration and cross-checks with the existing detectors.
3. Preliminary simulations show that the combined analysis of data from FAST and the surface detector array could provide an energy resolution of 10% and an Xmax resolution of 35 g/cm2 for protons at 10^19.5 eV.
Next-Generation Observatory: Fluorescence detector Array of Single Pixel Tele...Toshihiro FUJII
The document describes the proposed FAST (Fluorescence detector Array of Single-pixel Telescopes) concept for a next-generation ultra-high energy cosmic ray observatory. FAST would consist of 500 single-pixel telescope stations spaced 20 km apart, covering an area of 150,000 km2. Each station would have 12 telescopes with 48 photomultiplier tubes providing 360 degree coverage. This would provide over 10 times the exposure of current observatories like the Telescope Array and Pierre Auger Observatory. An initial prototype was successfully tested at the Telescope Array site in 2014, detecting air shower signals in coincidence with the Telescope Array fluorescence detector. Further R&D and construction of a full-scale FAST prototype is planned
A Conceptual Design for a Large Ground Array of Fluorescence DetectorsToshihiro FUJII
This document proposes a conceptual design for a large ground array of fluorescence detectors to study ultra-high energy cosmic rays. The design envisions an array covering over 40,000 km2 using a simplified fluorescence detector telescope with a single, large pixel and fresnel lens. It could achieve the same statistics as the Pierre Auger Observatory above 1019.5 eV but at a much lower cost by reducing the number of photomultiplier tubes and electronics. First simulations show the design could efficiently trigger on air showers using timing from three stations spaced 20 km apart with no surface detector required. The document calls for further R&D to develop this concept into a workable design for the next generation ultra-high energy cosmic ray observatory
Development of a prototype for Fluorescence detector Array of Single-pixel Te...Toshihiro FUJII
This document summarizes the results from the first field test of the Fluorescence detector Array of Single-pixel Telescopes (FAST) concept. The test involved a single FAST telescope prototype installed at the Telescope Array site in Utah. Key results included stable operation under night sky backgrounds, detection of laser shots and air shower signals consistent with expectations, and a successful collaboration between the Pierre Auger, Telescope Array and JEM-EUSO experiments. Future plans involve developing a full 30x30 degree prototype to further validate the FAST concept.
First results from a prototype for the Fluorescence detector Array of Single-...Toshihiro FUJII
The document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST) concept for observing ultra-high energy cosmic rays. The FAST prototype was tested using the EUSO-TA telescope and detected laser shots and 16 air shower candidates in coincidence with the Telescope Array fluorescence detector. A new FAST prototype is being constructed to establish its sensitivity and detect air shower profiles including the depth of shower maximum. The document outlines future plans to install FAST at the Pierre Auger Observatory and Telescope Array for cross-calibration and to independently measure energy and air shower maximum between the two experiments using a low-cost simplified fluorescence detector design.
Fluorescence detector Array of Single-pixel Telescopes (FAST) projectToshihiro FUJII
This document discusses the history and development of fluorescence detection techniques for ultra-high energy cosmic rays (UHECR). It proposes a new concept called the Fluorescence detector Array of Single-pixel Telescopes (FAST) project. FAST aims to develop an optimized and economical fluorescence detector array to observe UHECRs above 1019.5 eV over a large area. The document outlines the design of FAST stations and reports on an initial test using the EUSO-TA prototype that successfully detected laser pulses and UHECR signals. It concludes by discussing plans to construct a new full-scale FAST prototype and the potential for FAST to increase UHECR exposure and help resolve questions about their origin.
This document summarizes the results from field testing a prototype Fast Array of Single-Pixel Telescopes (FAST) for ultra-high energy cosmic ray detection. Key findings include:
1) The FAST prototype operated very stably and detected laser shots and air shower candidates consistent with expectations.
2) Reconstructed air shower maximum depths from FAST data alone could achieve 30 g/cm^2 resolution for energies above 10^19.5 eV.
3) Future improvements to the FAST design were identified, and a full 30°×30° prototype is the next step.
1. FAST実験14:新型⼤気蛍光望遠鏡による
南北半球での極⾼エネルギー宇宙線観測と
⾃⽴稼働へ向けた開発研究
http://www-cr.scphys.kyoto-u.ac.jp/m_ron/nagasawa_M.pdf
修⼠論⽂(京都⼤学宇宙線研究室のHPに掲載)
Justin Albury, Jose Bellido, Fraser Bradfield, Ladislav Chytka, John Farmer, Toshihiro Fujii, Petr Hamal, Pavel
Horvath, Miroslav Hrabovsky, Hiromu Iwasaki, Vlastimil Jilek, Jakub Kmec, Jiri Kvita, Max Malacari, Dusan
Mandat, Massimo Mastrodicasa, John Matthews, Stanislav Michal, Hiromu Nagasawa, Hiroki Namba,
Xiaochen Ni, Libor Nozka, Tomohiko Oka, Miroslav Palatka, Miroslav Pech, Paolo Privitera, Shunsuke Sakurai,
Francesco Salamida, Petr Schovanek, Radomir Smida, Zuzana Svozilikova, Stan Thomas, Akimichi Taketa,
Kenta Terauchi, Petr Travnicek, Martin Vacula (FAST Collaboration)
⻑澤 広武 (京都⼤学修⼠2年)
2023年3⽉24⽇ ⽇本物理学会 2023年春季⼤会 オンライン
2. 2
• 極⾼エネルギー宇宙線
(Ultra High Energy Cosmic Ray; UHECR)
• 最⼤で1020 eVを越えるようなエネルギーを持つ
• 1世紀あたり1 km2あたりわずか1個程度
極⾼エネルギー宇宙線
• 観測から推定されたUHECRの質量組成
• 1020 eV前後については、統計が少ないことと
ハドロン相互作⽤モデルの不定性により未解明
• 磁場で曲げられにくく、
加速源を特定すること
が可能
• 到来⽅向と既知の天体
との相関が期待
• ⾼エネルギー天体物理
現象の理解
(R. U. Abbasi, et al. 2014.)
1019.5 eV(=約30 EeV)
以上で観測事象数が
⾜りていない
銀河⾯ 超銀河⾯
ü 宇宙線の起源や加速機構の研究には、
年間観測事象数を1桁以上増やす必要がある
(Frank G. Schröder. ICRC2019) (Jose Bellido. ICRC2017)
有意度
3. 3
Fluorescence detector Array of
Single-pixel Telescopes (FAST)
• 低コストな⼤気蛍光望遠鏡(FD)アレイによる次世代の
宇宙線観測実験
• 分割鏡9枚からなる直径1.6 mの光学系
• 1台の望遠鏡につき4本の直径20 cmの光電⼦増倍管
• 各光電⼦増倍管ごとに15度×15度の視野⾓
ü 1ステーションあたり12台の望遠鏡を設置
ü 20 km間隔で500カ所に設置
ü 150,000 km2 (有効検出⾯積30,000 km2)
30 EeV以上での有効検出⾯積を現在稼働中の検出器の10倍に
20 km
(15 kmの例)
ü FAST-FDアレイの
配置イメージ
ü FAST-FDステーション
FDステーション
Ø 三⾓格⼦配置 & FDのみで構成
4. 4
FASTでの宇宙線観測
• 開発研究として望遠鏡(FAST-FD)を設置
• TAサイトに3台、Augerサイトに1台
• TAサイト:2016, 2017, 2018年設置
• Augerサイト:2019年設置
• 2023年度にAugerサイトへ2台⽬の設置予定
ü 現在はNIMモジュールを⽤いて観測
ü ⼤規模化(低消費電⼒, 48チャンネル読み出し)
に対応するためには新しいデータ取得システムの
開発が必要
ü TAサイトのFAST-FDによって観測された宇宙線
イベントの波形信号の例
(現状のデータ取得システムによる運⽤)
ü TAサイトのFAST-FD
1号機 2号機 3号機
ü FAST-FDの現状の
データ取得システム
(M. Malacari, et al., 2020.)
約4 µs
約4 µs
5. 5
ü 増幅率測定
光電⼦増倍管の基礎特性評価
• 実験室内にて光電⼦増倍管(Photomultiplier-Tube; PMT)の基礎特性評価
• Augerサイトに設置予定のFAST-FD 2台⽬に使⽤する4本のPMTについて評価
Ø 1光電⼦測定
• ゲインの絶対値を測定
Ø ゲインカーブ測定
• ゲインの相対変化を測定
• ロボットアーム先端にレーザー光源
• 波⻑ = 405 nm, 時間幅 = 80 ps
• 使⽤したPMT R5912-03
• 20 cm直径, ボックスアンドライン型
• 8段ダイノード, 最⼤印加電圧+2500V
ü PMT基礎特性評価の様⼦ ü PMT R5912-03
<例:GE0019の測定結果>
• ゲイン =
(0.971±0.005)×107
1 pe
2 pe
0 pe
<例:GE0019の測定結果>
• a = 4.42±0.05
4071 nT (X)
30511 nT (Y)
35803 nT (Z)
⻩線は地磁気の強度
à 観測中の印加電圧(ゲインが5x104になる電圧)を決定