KM2A(Kilometer-square Array)探测器阵列是LHAASO(Large High Altitude Air Shower Observatory)主体探测器阵列之一,7 000多个探测器和读出电子学在1 km2的实验范围内完全分离并均匀分布排列。在这样大型且分布不集中的高能物理实验中...KM2A(Kilometer-square Array)探测器阵列是LHAASO(Large High Altitude Air Shower Observatory)主体探测器阵列之一,7 000多个探测器和读出电子学在1 km2的实验范围内完全分离并均匀分布排列。在这样大型且分布不集中的高能物理实验中,简洁灵活可靠的电子学远程更新方案具有重要意义。KM2A读出电子学系统采用基于Multi Boot的远程更新方案,此方案实现了无需任何附加电路的远程更新及在线重加载,同时极大程度保证更新可靠性。展开更多
KM2A is one of the main sub-arrays of LHAASO,working on gamma ray astronomy and cosmic ray physics at energies above 10 TeV.Detector simulation is the important foundation for estimating detector performance and data ...KM2A is one of the main sub-arrays of LHAASO,working on gamma ray astronomy and cosmic ray physics at energies above 10 TeV.Detector simulation is the important foundation for estimating detector performance and data analysis.It is a big challenge to simulate the KM2A detector in the framework of Geant4 due to the need to track numerous photons from a large number of detector units(>6000)with large altitude difference(30)and huge coverage(1.3).In this paper,the design of the KM2A simulation code G4KM2A based on Geant4 is introduced.The process of G4KM2A is optimized mainly in memory consumption to avoid memory overflow.Some simplifications are used to significantly speed up the execution of G4KM2A.The running time is reduced by at least 30 times compared to full detector simulation.The particle distributions and the core/angle resolution comparison between simulation and experimental data of the full KM2A array are also presented,which show good agreement.展开更多
To fulfill the requirements for testing the photomultiplier tubes （PMTs） of the electromagnetic detec- tor at the Large High Altitude Air Shower Observatory （LHAASO）, a multi-functional PMT test bench with a two-d...To fulfill the requirements for testing the photomultiplier tubes （PMTs） of the electromagnetic detec- tor at the Large High Altitude Air Shower Observatory （LHAASO）, a multi-functional PMT test bench with a two-dimensional scanning system has been developed. With this 2D scanning system, 16 PMTs can be scanned simultaneously for characteristics tests, including uniformity, cathode transit time difference, single photo-electron spectrum, gain vs. high voltage, linear behavior and dark noise. of the test bench make it convenient to use and provide reliable primary results are presented. The programmable hardware and intelligent software results. The test methods are described in detail and展开更多
In the Large High Altitude Air Shower Observatory（LHAASO） project,the one kilometer square extensive air shower array（KM2A） is the the largest detector array in terms of effect ive area.It consists of 5635electrom...In the Large High Altitude Air Shower Observatory（LHAASO） project,the one kilometer square extensive air shower array（KM2A） is the the largest detector array in terms of effect ive area.It consists of 5635electromagnetic particle detectors（EDs） and 122 1 union detectors（MDs）.Each ED is composed of 16 scintillator tiles readout by wavelength-shifting fibers that are bundled and attached by a 25 mm PMT.The design of the unit and its performances,such as photoelectron yield,time resolution and uniformity,are discussed in detail.An assembling scheme for the whole ED is established to guarantee the uniformity throughout all 16 tiles in a single ED and all EDs in mass production.展开更多
A prototype array for the LHAASO-KM2A, which consists of 42 detector units and fully overlaps the ARGO-YBJ experiment, was set up at the Yangbajing cosmic ray observatory and has been in stable operation since Octoter...A prototype array for the LHAASO-KM2A, which consists of 42 detector units and fully overlaps the ARGO-YBJ experiment, was set up at the Yangbajing cosmic ray observatory and has been in stable operation since Octoter 2010. The resulting performances of the KM2A electromagnetic particle detector prototypes fully meet the design requirements. Through hybrid observation of cosmic ray showers with the ARGO-YBJ experiment, the performances and long-term stability of the prototype array are tested and the results are consistent with expectation. The cosmic ray moon shadow observed by the prototype array is also presented.展开更多
文摘KM2A(Kilometer-square Array)探测器阵列是LHAASO(Large High Altitude Air Shower Observatory)主体探测器阵列之一,7 000多个探测器和读出电子学在1 km2的实验范围内完全分离并均匀分布排列。在这样大型且分布不集中的高能物理实验中,简洁灵活可靠的电子学远程更新方案具有重要意义。KM2A读出电子学系统采用基于Multi Boot的远程更新方案,此方案实现了无需任何附加电路的远程更新及在线重加载,同时极大程度保证更新可靠性。
基金supported by the following grants:The National Key R&D program of China under grants 2018YFA0404201the National Natural Science Foundation of China(NSFC)No.12022502,No.12205314,No.12105301,No.12261160362,No.12105294,No.U1931201,No.12393851,No.12393854+1 种基金In Thailand,support was provided by the National Science and Technology Development Agency(NSTDA)the National Research Council of Thailand(NRCT)under the High-Potential Research Team Grant Program(N42A650868).
文摘KM2A is one of the main sub-arrays of LHAASO,working on gamma ray astronomy and cosmic ray physics at energies above 10 TeV.Detector simulation is the important foundation for estimating detector performance and data analysis.It is a big challenge to simulate the KM2A detector in the framework of Geant4 due to the need to track numerous photons from a large number of detector units(>6000)with large altitude difference(30)and huge coverage(1.3).In this paper,the design of the KM2A simulation code G4KM2A based on Geant4 is introduced.The process of G4KM2A is optimized mainly in memory consumption to avoid memory overflow.Some simplifications are used to significantly speed up the execution of G4KM2A.The running time is reduced by at least 30 times compared to full detector simulation.The particle distributions and the core/angle resolution comparison between simulation and experimental data of the full KM2A array are also presented,which show good agreement.
基金Supported by NSFC(11075096)SDNFS(ZR2011AM007),China
文摘To fulfill the requirements for testing the photomultiplier tubes （PMTs） of the electromagnetic detec- tor at the Large High Altitude Air Shower Observatory （LHAASO）, a multi-functional PMT test bench with a two-dimensional scanning system has been developed. With this 2D scanning system, 16 PMTs can be scanned simultaneously for characteristics tests, including uniformity, cathode transit time difference, single photo-electron spectrum, gain vs. high voltage, linear behavior and dark noise. of the test bench make it convenient to use and provide reliable primary results are presented. The programmable hardware and intelligent software results. The test methods are described in detail and
文摘In the Large High Altitude Air Shower Observatory（LHAASO） project,the one kilometer square extensive air shower array（KM2A） is the the largest detector array in terms of effect ive area.It consists of 5635electromagnetic particle detectors（EDs） and 122 1 union detectors（MDs）.Each ED is composed of 16 scintillator tiles readout by wavelength-shifting fibers that are bundled and attached by a 25 mm PMT.The design of the unit and its performances,such as photoelectron yield,time resolution and uniformity,are discussed in detail.An assembling scheme for the whole ED is established to guarantee the uniformity throughout all 16 tiles in a single ED and all EDs in mass production.
基金Supported by NSFC(11175147)Knowledge Innovation Fund of IHEP,Beijing
文摘A prototype array for the LHAASO-KM2A, which consists of 42 detector units and fully overlaps the ARGO-YBJ experiment, was set up at the Yangbajing cosmic ray observatory and has been in stable operation since Octoter 2010. The resulting performances of the KM2A electromagnetic particle detector prototypes fully meet the design requirements. Through hybrid observation of cosmic ray showers with the ARGO-YBJ experiment, the performances and long-term stability of the prototype array are tested and the results are consistent with expectation. The cosmic ray moon shadow observed by the prototype array is also presented.
