The Giant Radio Array for Neutrino Detection(GRAND)is a proposed large-scale observatory designed to detect cosmic rays,gamma-rays,and neutrinos with energies exceeding 100 Pe V.The GRANDProto300 experiment is propose...The Giant Radio Array for Neutrino Detection(GRAND)is a proposed large-scale observatory designed to detect cosmic rays,gamma-rays,and neutrinos with energies exceeding 100 Pe V.The GRANDProto300 experiment is proposed as the early stage of the GRAND project,consisting of a hybrid array of radio antennas and scintillator detectors.The latter,as a mature and traditional detector,is used to cross-check the nature of the candidate events selected from radio observations.In this study,we developed a simulation software called G4GRANDProto300,based on the Geant4 software package,to optimize the spacing of the scintillator detector array and to investigate its effective area.The analysis was conducted at various zenith angles under different detector spacings,including 300,500,600,700,and 900 m.Our results indicate that,for large zenith angles used to search for cosmic-ray in the GRAND project,the optimized effective area is with a detector spacing of 500 m.The G4GRANDProto300 software that we developed could be used to further optimize the layout of the particle detector array in future work.展开更多
The High Altitude Detection of Astronomical Radiation(HADAR)experiment,which was constructed in Tibet,China,combines the wide-angle advantages of traditional EAS array detectors with the high-sensitivity advantages of...The High Altitude Detection of Astronomical Radiation(HADAR)experiment,which was constructed in Tibet,China,combines the wide-angle advantages of traditional EAS array detectors with the high-sensitivity advantages of focused Cherenkov detectors.Its objective is to observe transient sources such as gamma-ray bursts and the counterparts of gravitational waves.This study aims to utilize the latest AI technology to enhance the sensitivity of HADAR experiments.Training datasets and models with distinctive creativity were constructed by incorporating the relevant physical theories for various applications.These models can determine the type,energy,and direction of the incident particles after careful design.We obtained a background identification accuracy of 98.6%,a relative energy reconstruction error of 10.0%,and an angular resolution of 0.22°in a test dataset at 10 TeV.These findings demonstrate the significant potential for enhancing the precision and dependability of detector data analysis in astrophysical research.By using deep learning techniques,the HADAR experiment’s observational sensitivity to the Crab Nebula has surpassed that of MAGIC and H.E.S.S.at energies below 0.5 TeV and remains competitive with conventional narrow-field Cherenkov telescopes at higher energies.In addition,our experiment offers a new approach for dealing with strongly connected,scattered data.展开更多
The experimental measurement of the total interaction cross sections of N,C,B,and Be isotopes on 12C target at medium energies is described.A new formula that gives a good description of the energy-range relationship ...The experimental measurement of the total interaction cross sections of N,C,B,and Be isotopes on 12C target at medium energies is described.A new formula that gives a good description of the energy-range relationship of energetic ions over a wide energy range is presented.The energy calibration of detectors is made by a Monte Carlo simulation method based on this new formula.展开更多
The angular distributions of intermediate mass fragments with charge numbers from 3 to 24 emitted in 30 MeV/u 40Ar+58,64Ni and 115In reactions over an angular range of 5o-140ohave been measured.In different angular re...The angular distributions of intermediate mass fragments with charge numbers from 3 to 24 emitted in 30 MeV/u 40Ar+58,64Ni and 115In reactions over an angular range of 5o-140ohave been measured.In different angular region an exponential distribution function dσ/dΩ=N exp(-θ/α)was used to fit the measured angular distributions.The decay factor a which can be connected with the interaction time T and the factor N which is related to the intensity of the emission sources have been extracted.The relationship ofα(Z)and N(Z)with Z for different reaction systems and different angular regions has been discussed.The different behavior of dσ/dΩ,α(Z),and N(Z)for the three studied reaction systems exists mainly in the middle and backward angular regions.The dependencies of angular distributions on isospin and the size of reaction systems have also been discussed.展开更多
Measurements of the total reaction cross section for^(12-16)C,^(14-17)N and^(16-18)O on carbon target at intermediate energies were performed on RIBLL of HIRFL.A larger enhancement ofσR for^(15)C was observed than th...Measurements of the total reaction cross section for^(12-16)C,^(14-17)N and^(16-18)O on carbon target at intermediate energies were performed on RIBLL of HIRFL.A larger enhancement ofσR for^(15)C was observed than that for its neighbors.The analysis of these data indicates possible existence of an anomalous nuclear structure in^(15)C.A new quantity was suggested as the criterion to distinguish anomalous structure nuclei from normal nuclei.展开更多
High spin states in ^(170)Ta have been studied via ^(159)Tb(^(16)O,5nγ)^(170)Ta reaction at 105MeV beam energy.Three rotational bands have been observed among which one coupled band and an unfavoredΔI=2 transition s...High spin states in ^(170)Ta have been studied via ^(159)Tb(^(16)O,5nγ)^(170)Ta reaction at 105MeV beam energy.Three rotational bands have been observed among which one coupled band and an unfavoredΔI=2 transition sequence of the semidecoupled band are identified in this work.The effects of theπ1/2^(-)[541]proton intruder orbital are qualitatively discussed.展开更多
An inclusive measurement was performed for 30 MeV/u ^(40)Ar+^(58,64)Ni and ^(115)In.By employing the degree of freedom of N/Z,the production mechanism of the high energy component of the intermediate mass fragments(IM...An inclusive measurement was performed for 30 MeV/u ^(40)Ar+^(58,64)Ni and ^(115)In.By employing the degree of freedom of N/Z,the production mechanism of the high energy component of the intermediate mass fragments(IMFs:3≤Z≤13)has been discussed.Special attention has been paid to the target dependence of N/Z ratio of the energetic fragments.These IMFs may be produced by a projectile fragmentation process with energy dissipation.展开更多
Combining observations of multi-messengers help in boosting the sensitivity of astrophysical source searches,and probe various aspects of the source physics.In this chapter we discuss how LHAASO observations of very h...Combining observations of multi-messengers help in boosting the sensitivity of astrophysical source searches,and probe various aspects of the source physics.In this chapter we discuss how LHAASO observations of very high energy(VHE)gamma rays in combination with telescopes for the other messengers can help in solving the origins of VHE neutrinos and galactic and extragalactic cosmic rays.展开更多
Background A total of 5195 electromagnetic particle detectors(EDs)are used in the 1-square-kilometer extensive air shower array(KM2A),which is a subarray of the Large High Altitude Air Shower Observatory(LHAASO).Purpo...Background A total of 5195 electromagnetic particle detectors(EDs)are used in the 1-square-kilometer extensive air shower array(KM2A),which is a subarray of the Large High Altitude Air Shower Observatory(LHAASO).Purpose As the detection sensitive medium of the EDs,more than 20,000 plastic scintillator units(BC-408),produced by Saint-Gobain,are used in LHAASO.It is important to monitor the light output of the scintillator units among the units.Method To improve the efficiency,a sampling inspection scheme(misjudgment rate of less than 5%)was designed,and a batch test system was developed.Ten units of scintillator units can be measured at a time.The test system selects the single muon events of cosmic rays to measure the light output values of the plastic scintillator units.Results The measurement has an uncertainty of less than 2%.By pretest calibration,the difference between different channels can be eliminated.The calibration was implemented approximately every 3 months,and the test system had been running stably for 28 months.By measuring the ratio of the signals of selected far and near probe events,the changes in the quality of different batches of plastic scintillator units can be demonstrated.Conclusions The test system realized accurate measurement of the light output,and all batches satisfied the requirements of the experiment.展开更多
Two low-lying isomeric states in 169Ta have been identified via ^(159)Tb(l6O,6nγ)^(169)Ta reaction.Their half-lives are measured to be 28±5ns for the 9/2^(-)level and 17±4 ns for the 5/2^(-)level by using t...Two low-lying isomeric states in 169Ta have been identified via ^(159)Tb(l6O,6nγ)^(169)Ta reaction.Their half-lives are measured to be 28±5ns for the 9/2^(-)level and 17±4 ns for the 5/2^(-)level by using the delayedγ-γcoincidence method.These two isomeric states are considered to be the bandheads with 9/2-[514]and 1/2-[541]configurations,respectively.Possible neutron quasiparticle configuration for the ground state of ^(169)W is discussed.展开更多
Fragments produced in the reaction of 60 MeV/n^(18)O on Be have been measured experimentally.The isotopic distribution of fragmentation reaction is well reproduced by a modified statistical abrasion-ablation model It ...Fragments produced in the reaction of 60 MeV/n^(18)O on Be have been measured experimentally.The isotopic distribution of fragmentation reaction is well reproduced by a modified statistical abrasion-ablation model It is predicted that the isotopic distribution shifts toward the neutron rich side for neutron rich projectile,but this isospin effect decreases with the increase of the atomic number difference Z-Z_(A)and disappears at last,where Z and Z_(A)are atomic numbers of the isotopic distribution and the projectile respectively.展开更多
The observation of short gamma ray bursts(SGRBs)in the TeV energy range plays an important role in understanding the radiation mechanism and probing potential new physics,such as Lorentz invariance violation(LIV).Howe...The observation of short gamma ray bursts(SGRBs)in the TeV energy range plays an important role in understanding the radiation mechanism and probing potential new physics,such as Lorentz invariance violation(LIV).However,no SGRBs have been observed in this energy range owing to the short duration of SGRBs and the weakness of current experiments.New experiments with new technology are required to detect the very high energy(VHE)emission of SGRBs.In this study,we simulate the VHE γ-ray emissions from SGRBs and calculate the annu-al detection rate with the High Altitude Detection of Astronomical Radiation(HADAR)experiment.First,a set of pseudo-SGRB samples is generated and checked using the observations of the Fermi-GBM,Fermi-LAT,and Swift-BAT measurements.The annual detection rate is calculated from these SGRB samples based on the performance of the HADAR instrument.As a result,the HADAR experiment can detect 0.5 SGRBs per year if the spectral break-off of γ-rays caused by the internal absorption and Klein-Nishina(KN)effect is larger than 100 GeV.For a GRB090510-like GRB in HADAR's view,it should be possible to detect approximately 2000 photons considering the internal absorption and KN effect.With a time delay assumption due to LIV effects,a simulated light curve of GRB090510 has evident energy dependence.We hope that the HADAR experiment can perform SGRB observa-tions and test our calculations in the future.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12322302,12275279 and U1931201)the National Key R&D Program of China(No.2023YFE0102300)+2 种基金the Project for Young Scientists in Basic Research of Chinese Academy of Sciences(No.YSBR-061)the Chinese Academy of Sciencesthe Entrepreneurship and Innovation Program of Jiangsu Province。
文摘The Giant Radio Array for Neutrino Detection(GRAND)is a proposed large-scale observatory designed to detect cosmic rays,gamma-rays,and neutrinos with energies exceeding 100 Pe V.The GRANDProto300 experiment is proposed as the early stage of the GRAND project,consisting of a hybrid array of radio antennas and scintillator detectors.The latter,as a mature and traditional detector,is used to cross-check the nature of the candidate events selected from radio observations.In this study,we developed a simulation software called G4GRANDProto300,based on the Geant4 software package,to optimize the spacing of the scintillator detector array and to investigate its effective area.The analysis was conducted at various zenith angles under different detector spacings,including 300,500,600,700,and 900 m.Our results indicate that,for large zenith angles used to search for cosmic-ray in the GRAND project,the optimized effective area is with a detector spacing of 500 m.The G4GRANDProto300 software that we developed could be used to further optimize the layout of the particle detector array in future work.
文摘The High Altitude Detection of Astronomical Radiation(HADAR)experiment,which was constructed in Tibet,China,combines the wide-angle advantages of traditional EAS array detectors with the high-sensitivity advantages of focused Cherenkov detectors.Its objective is to observe transient sources such as gamma-ray bursts and the counterparts of gravitational waves.This study aims to utilize the latest AI technology to enhance the sensitivity of HADAR experiments.Training datasets and models with distinctive creativity were constructed by incorporating the relevant physical theories for various applications.These models can determine the type,energy,and direction of the incident particles after careful design.We obtained a background identification accuracy of 98.6%,a relative energy reconstruction error of 10.0%,and an angular resolution of 0.22°in a test dataset at 10 TeV.These findings demonstrate the significant potential for enhancing the precision and dependability of detector data analysis in astrophysical research.By using deep learning techniques,the HADAR experiment’s observational sensitivity to the Crab Nebula has surpassed that of MAGIC and H.E.S.S.at energies below 0.5 TeV and remains competitive with conventional narrow-field Cherenkov telescopes at higher energies.In addition,our experiment offers a new approach for dealing with strongly connected,scattered data.
基金Supported by the National Science Foundation of China for Distinguished Young Scholar under Grand No.19625513.
文摘The experimental measurement of the total interaction cross sections of N,C,B,and Be isotopes on 12C target at medium energies is described.A new formula that gives a good description of the energy-range relationship of energetic ions over a wide energy range is presented.The energy calibration of detectors is made by a Monte Carlo simulation method based on this new formula.
基金Supported by the National Natural Science Foundation of China under Grant No.19235012the Foundation of Chinese Academy of Sciences。
文摘The angular distributions of intermediate mass fragments with charge numbers from 3 to 24 emitted in 30 MeV/u 40Ar+58,64Ni and 115In reactions over an angular range of 5o-140ohave been measured.In different angular region an exponential distribution function dσ/dΩ=N exp(-θ/α)was used to fit the measured angular distributions.The decay factor a which can be connected with the interaction time T and the factor N which is related to the intensity of the emission sources have been extracted.The relationship ofα(Z)and N(Z)with Z for different reaction systems and different angular regions has been discussed.The different behavior of dσ/dΩ,α(Z),and N(Z)for the three studied reaction systems exists mainly in the middle and backward angular regions.The dependencies of angular distributions on isospin and the size of reaction systems have also been discussed.
基金Supported by the National Natural Science Foundation of China for Distinguished Young Scholar under Grand No.19625513National Natural Science Foundation of China under Grant No.19675059+1 种基金Shanghai Science,Technology Development Fund under Grant No.96XD14011Major State Basic Research Development Program(G200077400).
文摘Measurements of the total reaction cross section for^(12-16)C,^(14-17)N and^(16-18)O on carbon target at intermediate energies were performed on RIBLL of HIRFL.A larger enhancement ofσR for^(15)C was observed than that for its neighbors.The analysis of these data indicates possible existence of an anomalous nuclear structure in^(15)C.A new quantity was suggested as the criterion to distinguish anomalous structure nuclei from normal nuclei.
基金Supported by the State Education Commit tee of Chinathe National Natural Science Foundation of China under Grant No 19605008。
文摘High spin states in ^(170)Ta have been studied via ^(159)Tb(^(16)O,5nγ)^(170)Ta reaction at 105MeV beam energy.Three rotational bands have been observed among which one coupled band and an unfavoredΔI=2 transition sequence of the semidecoupled band are identified in this work.The effects of theπ1/2^(-)[541]proton intruder orbital are qualitatively discussed.
基金Supported by the National Natural Science Foundation of China under Grant No.19205006.
文摘An inclusive measurement was performed for 30 MeV/u ^(40)Ar+^(58,64)Ni and ^(115)In.By employing the degree of freedom of N/Z,the production mechanism of the high energy component of the intermediate mass fragments(IMFs:3≤Z≤13)has been discussed.Special attention has been paid to the target dependence of N/Z ratio of the energetic fragments.These IMFs may be produced by a projectile fragmentation process with energy dissipation.
基金Supported by the Natural Science Foundation of China(11773003,11875264,12003007,12173091,U1931201,U2031105)the Fundamental Research Funds for the Central Universities(2020kfyXJJS039)。
文摘Combining observations of multi-messengers help in boosting the sensitivity of astrophysical source searches,and probe various aspects of the source physics.In this chapter we discuss how LHAASO observations of very high energy(VHE)gamma rays in combination with telescopes for the other messengers can help in solving the origins of VHE neutrinos and galactic and extragalactic cosmic rays.
基金Thiswork is supported byNationalKeyR&Dpro-gram of China under the grant 2018YFA0404201by the National Nat-ural Science Foundation of China(Grant Nos.11805209,12022502)the Chinese Academy of Science,Institute of High Energy Physics.
文摘Background A total of 5195 electromagnetic particle detectors(EDs)are used in the 1-square-kilometer extensive air shower array(KM2A),which is a subarray of the Large High Altitude Air Shower Observatory(LHAASO).Purpose As the detection sensitive medium of the EDs,more than 20,000 plastic scintillator units(BC-408),produced by Saint-Gobain,are used in LHAASO.It is important to monitor the light output of the scintillator units among the units.Method To improve the efficiency,a sampling inspection scheme(misjudgment rate of less than 5%)was designed,and a batch test system was developed.Ten units of scintillator units can be measured at a time.The test system selects the single muon events of cosmic rays to measure the light output values of the plastic scintillator units.Results The measurement has an uncertainty of less than 2%.By pretest calibration,the difference between different channels can be eliminated.The calibration was implemented approximately every 3 months,and the test system had been running stably for 28 months.By measuring the ratio of the signals of selected far and near probe events,the changes in the quality of different batches of plastic scintillator units can be demonstrated.Conclusions The test system realized accurate measurement of the light output,and all batches satisfied the requirements of the experiment.
基金Supported by the State Education Committee of Chinathe National Natural Science Foundation of China under Grant No.19605008.
文摘Two low-lying isomeric states in 169Ta have been identified via ^(159)Tb(l6O,6nγ)^(169)Ta reaction.Their half-lives are measured to be 28±5ns for the 9/2^(-)level and 17±4 ns for the 5/2^(-)level by using the delayedγ-γcoincidence method.These two isomeric states are considered to be the bandheads with 9/2-[514]and 1/2-[541]configurations,respectively.Possible neutron quasiparticle configuration for the ground state of ^(169)W is discussed.
基金Supported by the National Natural Science Foundation of China for Distinguished Young Scholar under Grand No.19625513National Natural Science Foundation of China under Grant No.19675059Shanghai Science and Technology Development Fund under Grant No.96XD14011.
文摘Fragments produced in the reaction of 60 MeV/n^(18)O on Be have been measured experimentally.The isotopic distribution of fragmentation reaction is well reproduced by a modified statistical abrasion-ablation model It is predicted that the isotopic distribution shifts toward the neutron rich side for neutron rich projectile,but this isospin effect decreases with the increase of the atomic number difference Z-Z_(A)and disappears at last,where Z and Z_(A)are atomic numbers of the isotopic distribution and the projectile respectively.
基金Supported by the National Natural Science Foundation of China(12263004,12263005,12275279)。
文摘The observation of short gamma ray bursts(SGRBs)in the TeV energy range plays an important role in understanding the radiation mechanism and probing potential new physics,such as Lorentz invariance violation(LIV).However,no SGRBs have been observed in this energy range owing to the short duration of SGRBs and the weakness of current experiments.New experiments with new technology are required to detect the very high energy(VHE)emission of SGRBs.In this study,we simulate the VHE γ-ray emissions from SGRBs and calculate the annu-al detection rate with the High Altitude Detection of Astronomical Radiation(HADAR)experiment.First,a set of pseudo-SGRB samples is generated and checked using the observations of the Fermi-GBM,Fermi-LAT,and Swift-BAT measurements.The annual detection rate is calculated from these SGRB samples based on the performance of the HADAR instrument.As a result,the HADAR experiment can detect 0.5 SGRBs per year if the spectral break-off of γ-rays caused by the internal absorption and Klein-Nishina(KN)effect is larger than 100 GeV.For a GRB090510-like GRB in HADAR's view,it should be possible to detect approximately 2000 photons considering the internal absorption and KN effect.With a time delay assumption due to LIV effects,a simulated light curve of GRB090510 has evident energy dependence.We hope that the HADAR experiment can perform SGRB observa-tions and test our calculations in the future.
文摘HADAR(High Altitude Detection of Astronomical Radiation)是一个基于大气切伦科夫成像技术的地面望远镜阵列,其采用大口径折射式水透镜系统来收集大气切伦科夫光,以实现对10 GeV—10 TeV能量段的伽马射线和宇宙线的探测.HADAR具有低阈能和大视场的优势,因此可以对天区进行连续扫描和观测,在观测活动星系核(Active Galactic Nuclei,AGN)等银河系外伽马射线源方面具有明显优势.本文研究了HADAR实验对AGN的探测能力.基于费米望远镜(Fermi Large Area Telescope,Fermi-LAT)的AGN源能谱信息,将观测能量外推至甚高能能段,同时加入河外背景光的吸收效应,以计算HADAR对AGN源观测的统计显著性.研究结果显示,HADAR运行一年时间,预计将有31个Fermi-LAT AGN源以高于5倍显著性被观测到,其中大部分为蝎虎状天体类型.
