Charge breeding technique is used for RIB (radioactive ion beam) production in order of optimizing the re-acceleration of the radioactive isotopes produced by a primary beam in a thick target. Charge breeding is ach...Charge breeding technique is used for RIB (radioactive ion beam) production in order of optimizing the re-acceleration of the radioactive isotopes produced by a primary beam in a thick target. Charge breeding is achieved by means of a device capable of increasing the ion charge state from 1+ to a desired value n+. In some experiments, a continuous RIB of a given energy may be required. To reach this goal, a charge breeding device based on a hollow gun EBIS (electron beam ion source) has been proposed by the author recently. That EBIS, in principle, can be capable to realize a CW (continuous wave) operation. A sufficiently high focusing magnetic field could reduce to zero the hole radius in the EBIS electron beam. However, a smaller efficiency in the ion charge state increase should be expected. A code developed for studying the ion selective containment in a EBIS has been modified and used to simulate the ion charge state breeding. The effects of the hollow electron beam on the breeding rate have been studied.展开更多
We show how the star formation activity of galaxies is progressively inhibited from the outer region to the center of the massive cluster A2142.From an extended spectroscopic redshift survey of 2239 galaxies covering ...We show how the star formation activity of galaxies is progressively inhibited from the outer region to the center of the massive cluster A2142.From an extended spectroscopic redshift survey of 2239 galaxies covering a circular area of radius~11 Mpc from the cluster center,we extract a sample of 333 galaxies with known stellar mass,star formation rate,and spectral index D_(n)4000.We use the Blooming Tree algorithm to identify the substructures of the cluster and separate the galaxy sample into substructure galaxies,halo galaxies,and outskirt galaxies.The substructure and halo galaxies are cluster members,whereas the outskirt galaxies are only weakly gravitationally bound to the cluster.For the cluster members,the star formation rate per stellar mass decreases with decreasing distance R from the cluster center.Similarly,the spectral index D_(n)4000 increases with R,indicating an increasing average age of the stellar population in galaxies closer to the cluster center.In addition,star formation in substructure galaxies is generally more active than in halo galaxies and less active than in outskirt galaxies,proving that substructures tend to slow down the transition between field galaxies and cluster galaxies.We finally show that most actively star-forming galaxies are within the cluster infall region,whereas most galaxies in the central region are quiescent.展开更多
We discuss a novel window to probe the origin of our universe via the mass functions of primordial black holes(PBHs).The mass functions of PBHs are simply estimated using the conventional Press-Schechter formalism for...We discuss a novel window to probe the origin of our universe via the mass functions of primordial black holes(PBHs).The mass functions of PBHs are simply estimated using the conventional Press-Schechter formalism for two paradigms of cosmic origin,including inflationaryΛCDM and bounce cosmology.The standard inflationaryΛCDM model cannot generate an appreciable number of massive PBHs;however,non-trivial inflation models with blue-tilted power spectra at small scales and matter bounce cosmology provide formation mechanisms for heavy PBHs,which in turn,may seed the observed supermassive black holes(SMBHs).By fitting the SMBH mass functions at high redshift(z~6)derived from Sloan Digital Sky Survey(SDSS)and Canada-France High-z Quasar Survey(CFHQS)quasars,for two paradigms of cosmic origin,we derive constraints on the PBH density fraction fPBHat z~6 and the characteristic mass M_(★),with the prior assumption that all SMBHs stem from PBHs.We demonstrate that this newly proposed procedure,relying on astronomical measurements that utilize deep-field surveys of SMBHs at high redshift,can be used to constrain models of cosmic origin.Additionally,although not the main focus of this paper,we evolve the mass function from z~6 to z~0 through an assumption of 3×10^(8)-year Eddington’s accretion,and give a rough estimation of fPBHat z~0.展开更多
The DArk Matter Particle Explorer(DAMPE)is a satellite-borne detector for high-energy cosmic rays and y-rays.To fully understand the detector performance and obtain reliable physical results,extensive simulations of t...The DArk Matter Particle Explorer(DAMPE)is a satellite-borne detector for high-energy cosmic rays and y-rays.To fully understand the detector performance and obtain reliable physical results,extensive simulations of the detector are necessary.The simulations are particularly important for the data analysis of cosmic ray nuclei,which relies closely on the hadronic and nuclear interactions of particles in the detector material.Widely adopted simulation softwares include the GEANT4 and FLUKA,both of which have been implemented for the DAMPE simulation tool.Here we describe the simulation tool of DAMPE and compare the results of proton shower properties in the calorimeter from the two simulation softwares.Such a comparison gives an estimate of the most significant uncertainties of our proton spectral analysis.展开更多
The DArk Matter Particle Explorer(DAMPE) is a space-borne apparatus for detecting the highenergy cosmic-ray-like electrons, γ-rays, protons and heavy ions. The Plastic Scintillator Detector(PSD)is the top-most sub-de...The DArk Matter Particle Explorer(DAMPE) is a space-borne apparatus for detecting the highenergy cosmic-ray-like electrons, γ-rays, protons and heavy ions. The Plastic Scintillator Detector(PSD)is the top-most sub-detector of the DAMPE. The PSD is designed to measure the charge of incident highenergy particles and it also serves as a veto detector for discriminating γ-rays from charged particles. In this paper, a PSD on-orbit calibration procedure is described, which includes the five steps of pedestal, dynode correlation, response to minimum-ionizing particles, light attenuation function and energy reconstruction.A method for reconstructing the charge of incident high energy cosmic-ray particles is introduced. The detection efficiency of each PSD strip is verified to be above 99.5%; the total efficiency of the PSD for charged particles is above 99.99%.展开更多
DArk Matter Particle Explorer(DAMPE) is a general purpose high energy cosmic ray and gamma ray observatory, aiming to detect high energy electrons and gammas in the energy range 5 Ge V to 10 Te V and hundreds of Te V ...DArk Matter Particle Explorer(DAMPE) is a general purpose high energy cosmic ray and gamma ray observatory, aiming to detect high energy electrons and gammas in the energy range 5 Ge V to 10 Te V and hundreds of Te V for nuclei. This paper provides a method using machine learning to identify electrons and separate them from gammas, protons, helium and heavy nuclei with the DAMPE data acquired from 2016 January 1 to 2017 June 30, in the energy range from 10 to 100 Ge V.展开更多
In the last few years, the cloud computing model has moved from hype to reality, as witnessed by the increasing number of commercial providers offering their cloud computing solutions. At the same time, various open-s...In the last few years, the cloud computing model has moved from hype to reality, as witnessed by the increasing number of commercial providers offering their cloud computing solutions. At the same time, various open-source projects are developing cloud computing frameworks open to experimental instrumentation and study. In this work we analyze Eucalyptus Community Cloud, an open-source cloud-computing framework delivering the IaaS model and running under the Linux operating system. Our aim is to present some of the results of our analysis and to propose some enhancements that can make Eucalyptus Community Cloud even more attractive for building both private and community cloud infrastructures, but also with an eye toward public clouds. In addition, we present a to-do list that may hopefully help users in the task of configuring and running their own Linux (and Windows) guests with Eucalyptus.展开更多
Indoor radon concentration measurements were performed in dwellings of Ischia island (South Italy) using commercial E-Perm devices in LST configuration. The average concentrations in the dwellings were found to vary f...Indoor radon concentration measurements were performed in dwellings of Ischia island (South Italy) using commercial E-Perm devices in LST configuration. The average concentrations in the dwellings were found to vary from 125 to 865 Bq/m3 with an average of 354 ± 176 Bq/m3. This value is higher than Italian National average that is 75 Bq/m3 and Campanian average that is 95 Bq/m3. Correlation between indoor radon concentration measurements and floor level of monitored room was also studied.展开更多
Implementation of laser-plasma-based acceleration stages in user-oriented facilities requires the definition and deployment of appropriate diagnostic methodologies to monitor and control the acceleration process.An ov...Implementation of laser-plasma-based acceleration stages in user-oriented facilities requires the definition and deployment of appropriate diagnostic methodologies to monitor and control the acceleration process.An overview is given here of optical diagnostics for density measurement in laser-plasma acceleration stages,with emphasis on wellestablished and easily implemented approaches.Diagnostics for both neutral gas and free-electron number density are considered,highlighting real-time measurement capabilities.Optical interferometry,in its various configurations,from standard two-arm to more advanced common-path designs,is discussed,along with spectroscopic techniques such as Stark broadening and Raman scattering.A critical analysis of the diagnostics presented is given concerning their implementation in laser-plasma acceleration stages for the production of high-quality GeV electron bunches.展开更多
We present the main features of the ultrashort, high-intensity laser installation at the Intense Laser Irradiation Laboratory(ILIL) including laser, beam transport and target area specifications. The laboratory was de...We present the main features of the ultrashort, high-intensity laser installation at the Intense Laser Irradiation Laboratory(ILIL) including laser, beam transport and target area specifications. The laboratory was designed to host laser–target interaction experiments of more than 220 TW peak power, in flexible focusing configurations, with ultrarelativistic intensity on the target. Specifications have been established via dedicated optical diagnostic assemblies and commissioning interaction experiments. In this paper we give a summary of laser specifications available to users,including spatial, spectral and temporal contrast features. The layout of the experimental target areas is presented, with attention to the available configurations of laser focusing geometries and diagnostics. Finally, we discuss radiation protection measures and mechanical stability of the laser focal spot on the target.展开更多
CSES(China Seismo-Electromagnetic Satellite) is a mission developed by CNSA(Chinese National Space Administration) and ASI(Italian Space Agency), to investigate the near-Earth electromagnetic, plasma and particle envi...CSES(China Seismo-Electromagnetic Satellite) is a mission developed by CNSA(Chinese National Space Administration) and ASI(Italian Space Agency), to investigate the near-Earth electromagnetic, plasma and particle environment, for studying the seismo-associated disturbances in the ionosphere-magnetosphere transition zone. The anthropogenic and electromagnetic noise,as well as the natural non-seismic electromagnetic emissions is mainly due to tropospheric activity. In particular, the mission aims to confirming the existence of possible temporal correlations between the occurrence of earthquakes for medium and strong magnitude and the observation in space of electromagnetic perturbations, plasma variations and precipitation of bursts with highenergy charged particles from the inner Van Allen belt. In this framework, the high energy particle detector(HEPD) of the CSES mission has been developed by the Italian LIMADOU Collaboration. HEPD is an advanced detector based on a tower of scintillators and a silicon tracker that provides good energy and angular resolution and a wide angular acceptance, for electrons of 3–100 Me V, protons of 30–200 Me V and light nuclei up to the oxygen. CSES satellite has been launched on February 2^(nd), 2018 from the Jiuquan Satellite Launch Center(China).展开更多
Background The plastic scintillator detector(PSD)is one of the detectors in the high energy cosmic radiation detection(HERD)facility,which is designed for gamma-ray detection and a redundant charge measurement.Backspl...Background The plastic scintillator detector(PSD)is one of the detectors in the high energy cosmic radiation detection(HERD)facility,which is designed for gamma-ray detection and a redundant charge measurement.Backsplash will lead to a decrease in PSD’s performance of gamma-ray detection and charge measurement,which should be carefully considered.Purpose Two preliminary segmentation schemes of the PSD and two veto strategies have been proposed to suppress the backsplash effect.In this paper,we focus on the influence of the backsplash caused by gamma rays.The gamma-ray trigger efficiency and identification efficiency were studied in the case of different cell sizes and veto strategies,which can provide guidance on the PSD design.Methods A Monte Carlo simulation based on Geant4 has been performed.To simplify the simulation,the PSD is segmented into 1 cm3 cubes which can be easily aggregated into cells with different sizes during analysis.Results and conclusion Side_Veto can be used as a baseline design of veto strategy,whereas Smart_Veto can be selected as an upgraded design.Both the PSD bar cell with a width of less than 11 cm and the PSD tile cell with a width of less than 20 cm can achieve a sufficiently high gamma-ray trigger efficiency(>80%),which realizes the primary goal of the PSD.Meanwhile,both the PSD bar cell with a width of less than 3 cm and the PSD tile cell with a width of less than 20 cm can ensure a sufficiently high gamma-ray identification efficiency(>80%)for photons up to 800 GeV.展开更多
文摘Charge breeding technique is used for RIB (radioactive ion beam) production in order of optimizing the re-acceleration of the radioactive isotopes produced by a primary beam in a thick target. Charge breeding is achieved by means of a device capable of increasing the ion charge state from 1+ to a desired value n+. In some experiments, a continuous RIB of a given energy may be required. To reach this goal, a charge breeding device based on a hollow gun EBIS (electron beam ion source) has been proposed by the author recently. That EBIS, in principle, can be capable to realize a CW (continuous wave) operation. A sufficiently high focusing magnetic field could reduce to zero the hole radius in the EBIS electron beam. However, a smaller efficiency in the ion charge state increase should be expected. A code developed for studying the ion selective containment in a EBIS has been modified and used to simulate the ion charge state breeding. The effects of the hollow electron beam on the breeding rate have been studied.
基金supported by Bureau of International Cooperation,Chinese Academy of Sciences GJHZ1864partial support from the INFN grant InDark。
文摘We show how the star formation activity of galaxies is progressively inhibited from the outer region to the center of the massive cluster A2142.From an extended spectroscopic redshift survey of 2239 galaxies covering a circular area of radius~11 Mpc from the cluster center,we extract a sample of 333 galaxies with known stellar mass,star formation rate,and spectral index D_(n)4000.We use the Blooming Tree algorithm to identify the substructures of the cluster and separate the galaxy sample into substructure galaxies,halo galaxies,and outskirt galaxies.The substructure and halo galaxies are cluster members,whereas the outskirt galaxies are only weakly gravitationally bound to the cluster.For the cluster members,the star formation rate per stellar mass decreases with decreasing distance R from the cluster center.Similarly,the spectral index D_(n)4000 increases with R,indicating an increasing average age of the stellar population in galaxies closer to the cluster center.In addition,star formation in substructure galaxies is generally more active than in halo galaxies and less active than in outskirt galaxies,proving that substructures tend to slow down the transition between field galaxies and cluster galaxies.We finally show that most actively star-forming galaxies are within the cluster infall region,whereas most galaxies in the central region are quiescent.
基金supported in part by the National Key R&D Program of China(Grant No.2021YFC2203100)CAS Young Interdisciplinary Innovation Team(Grant No.JCTD-2022-20)+11 种基金National Natural Science Foundation of China(Grant Nos.11875113,11961131007,12261131497,12003029,11833005,and 12192224)111 Project for“Observational and Theoretical Research on Dark Matter and Dark Energy”(Grant No.B23042)Fundamental Research Funds for Central UniversitiesCSC Innovation Talent FundsUSTC Fellowship for International CooperationUSTC Research Funds of the Double First-Class InitiativeCAS project for young scientists in basic research(Grant No.YSBR-006)Shanghai Municipality Science and Technology Commission(Grant No.KBH1512299)supported by the Disposizione del Presidente INFN n.24433 in INFN Sezione di Milanosupported in part by the U.S.Department of Energy,Office of High Energy Physics(Grant No.DE-SC0019470)the Foundational Questions Institute(Grant No.FQXi-MGB-1927)the use of the computing cluster LINDA&JUDY in the particle cosmology group at USTC。
文摘We discuss a novel window to probe the origin of our universe via the mass functions of primordial black holes(PBHs).The mass functions of PBHs are simply estimated using the conventional Press-Schechter formalism for two paradigms of cosmic origin,including inflationaryΛCDM and bounce cosmology.The standard inflationaryΛCDM model cannot generate an appreciable number of massive PBHs;however,non-trivial inflation models with blue-tilted power spectra at small scales and matter bounce cosmology provide formation mechanisms for heavy PBHs,which in turn,may seed the observed supermassive black holes(SMBHs).By fitting the SMBH mass functions at high redshift(z~6)derived from Sloan Digital Sky Survey(SDSS)and Canada-France High-z Quasar Survey(CFHQS)quasars,for two paradigms of cosmic origin,we derive constraints on the PBH density fraction fPBHat z~6 and the characteristic mass M_(★),with the prior assumption that all SMBHs stem from PBHs.We demonstrate that this newly proposed procedure,relying on astronomical measurements that utilize deep-field surveys of SMBHs at high redshift,can be used to constrain models of cosmic origin.Additionally,although not the main focus of this paper,we evolve the mass function from z~6 to z~0 through an assumption of 3×10^(8)-year Eddington’s accretion,and give a rough estimation of fPBHat z~0.
基金Supported by the National Key Research and Development Program of China(Grant No.2016YFA0400200)the National Natural Science Foundation of China(Grant Nos.11722328,11773085,U1738127,U1738138,U1738205,U1738207,and 11851305)+4 种基金the 100 Talents Program of Chinese Academy of Sciencesthe Youth Innovation Promotion Association CASthe Program for Innovative Talents and Entrepreneur in Jiangsusupported by the Swiss National Science Foundation(SNSF),Switzerlandthe National Institute for Nuclear Physics(INFN),Italy。
文摘The DArk Matter Particle Explorer(DAMPE)is a satellite-borne detector for high-energy cosmic rays and y-rays.To fully understand the detector performance and obtain reliable physical results,extensive simulations of the detector are necessary.The simulations are particularly important for the data analysis of cosmic ray nuclei,which relies closely on the hadronic and nuclear interactions of particles in the detector material.Widely adopted simulation softwares include the GEANT4 and FLUKA,both of which have been implemented for the DAMPE simulation tool.Here we describe the simulation tool of DAMPE and compare the results of proton shower properties in the calorimeter from the two simulation softwares.Such a comparison gives an estimate of the most significant uncertainties of our proton spectral analysis.
基金funded by the National Key Research and Development Program of China (2016YFA0400201)supported by the National Natural Science Foundation of China (11673047,11673075, 11303107, U1738127 and U1738205)
文摘The DArk Matter Particle Explorer(DAMPE) is a space-borne apparatus for detecting the highenergy cosmic-ray-like electrons, γ-rays, protons and heavy ions. The Plastic Scintillator Detector(PSD)is the top-most sub-detector of the DAMPE. The PSD is designed to measure the charge of incident highenergy particles and it also serves as a veto detector for discriminating γ-rays from charged particles. In this paper, a PSD on-orbit calibration procedure is described, which includes the five steps of pedestal, dynode correlation, response to minimum-ionizing particles, light attenuation function and energy reconstruction.A method for reconstructing the charge of incident high energy cosmic-ray particles is introduced. The detection efficiency of each PSD strip is verified to be above 99.5%; the total efficiency of the PSD for charged particles is above 99.99%.
基金supported by the State Key Project of Research and Development Plan (2016YFA0400204)the National Natural Science Foundation of China (U1738133)+3 种基金Strategic Pioneer Research Program in Space Science of the Chinese Academy of Science (CAS)Youth Innovation Promotion Association of CASMinistry of Science and Technology of Jiangsu Province (17KJD510001)Changzhou Institute of Technology (YN1611)
文摘DArk Matter Particle Explorer(DAMPE) is a general purpose high energy cosmic ray and gamma ray observatory, aiming to detect high energy electrons and gammas in the energy range 5 Ge V to 10 Te V and hundreds of Te V for nuclei. This paper provides a method using machine learning to identify electrons and separate them from gammas, protons, helium and heavy nuclei with the DAMPE data acquired from 2016 January 1 to 2017 June 30, in the energy range from 10 to 100 Ge V.
文摘In the last few years, the cloud computing model has moved from hype to reality, as witnessed by the increasing number of commercial providers offering their cloud computing solutions. At the same time, various open-source projects are developing cloud computing frameworks open to experimental instrumentation and study. In this work we analyze Eucalyptus Community Cloud, an open-source cloud-computing framework delivering the IaaS model and running under the Linux operating system. Our aim is to present some of the results of our analysis and to propose some enhancements that can make Eucalyptus Community Cloud even more attractive for building both private and community cloud infrastructures, but also with an eye toward public clouds. In addition, we present a to-do list that may hopefully help users in the task of configuring and running their own Linux (and Windows) guests with Eucalyptus.
文摘Indoor radon concentration measurements were performed in dwellings of Ischia island (South Italy) using commercial E-Perm devices in LST configuration. The average concentrations in the dwellings were found to vary from 125 to 865 Bq/m3 with an average of 354 ± 176 Bq/m3. This value is higher than Italian National average that is 75 Bq/m3 and Campanian average that is 95 Bq/m3. Correlation between indoor radon concentration measurements and floor level of monitored room was also studied.
基金support from the European Unions Horizon 2020 research and innovation program under Grant Agreement No.653782-EuPRAXIAthe MIUR-funded Italian research Network ELI-Italy
文摘Implementation of laser-plasma-based acceleration stages in user-oriented facilities requires the definition and deployment of appropriate diagnostic methodologies to monitor and control the acceleration process.An overview is given here of optical diagnostics for density measurement in laser-plasma acceleration stages,with emphasis on wellestablished and easily implemented approaches.Diagnostics for both neutral gas and free-electron number density are considered,highlighting real-time measurement capabilities.Optical interferometry,in its various configurations,from standard two-arm to more advanced common-path designs,is discussed,along with spectroscopic techniques such as Stark broadening and Raman scattering.A critical analysis of the diagnostics presented is given concerning their implementation in laser-plasma acceleration stages for the production of high-quality GeV electron bunches.
基金The ILIL-PW upgrade was established in the framework of the Italian Research Network on Extreme Light Infrastructure(ELI-Italy)funded by CNRfinancial contribution from the Eu PRAXIA project of the EU Horizon 2020 Research and Innovation Program under Grant Agreement No.653782the Line for Laser Light Ion Acceleration(L3IA)project funded by INFN,Italy。
文摘We present the main features of the ultrashort, high-intensity laser installation at the Intense Laser Irradiation Laboratory(ILIL) including laser, beam transport and target area specifications. The laboratory was designed to host laser–target interaction experiments of more than 220 TW peak power, in flexible focusing configurations, with ultrarelativistic intensity on the target. Specifications have been established via dedicated optical diagnostic assemblies and commissioning interaction experiments. In this paper we give a summary of laser specifications available to users,including spatial, spectral and temporal contrast features. The layout of the experimental target areas is presented, with attention to the available configurations of laser focusing geometries and diagnostics. Finally, we discuss radiation protection measures and mechanical stability of the laser focal spot on the target.
基金supported in part by the National Key R&D Program of China(2021YFC2203100)CAS Young Interdisciplinary Innovation Team(JCTD-2022–20)+8 种基金the National Natural Science Foundation of China(11875113,11961131007,12261131497,12003029,11833005,and 12192224)the 111 Project for“Observational and Theoretical Research on Dark Matter and Dark Energy”(B23042)Fundamental Research Funds for Central Universitiesthe Disposizione del Presidente INFN n.24433 in INFN Sezione di MilanoChina Postdoctoral Science Foundation(2023TQ0355)CSC Innovation Talent FundsUSTC Fellowship for International CooperationUSTC Research Funds of the Double First-Class InitiativeCAS project for young scientists in basic research(YSBR-006)。
基金supported by the Italian Space Agency in the framework of the“Accordo Attuativo n.2016-16-H0 Progetto Limadou Fase E/Scienza”(CUP F12F1600011005)
文摘CSES(China Seismo-Electromagnetic Satellite) is a mission developed by CNSA(Chinese National Space Administration) and ASI(Italian Space Agency), to investigate the near-Earth electromagnetic, plasma and particle environment, for studying the seismo-associated disturbances in the ionosphere-magnetosphere transition zone. The anthropogenic and electromagnetic noise,as well as the natural non-seismic electromagnetic emissions is mainly due to tropospheric activity. In particular, the mission aims to confirming the existence of possible temporal correlations between the occurrence of earthquakes for medium and strong magnitude and the observation in space of electromagnetic perturbations, plasma variations and precipitation of bursts with highenergy charged particles from the inner Van Allen belt. In this framework, the high energy particle detector(HEPD) of the CSES mission has been developed by the Italian LIMADOU Collaboration. HEPD is an advanced detector based on a tower of scintillators and a silicon tracker that provides good energy and angular resolution and a wide angular acceptance, for electrons of 3–100 Me V, protons of 30–200 Me V and light nuclei up to the oxygen. CSES satellite has been launched on February 2^(nd), 2018 from the Jiuquan Satellite Launch Center(China).
基金This research was supported by Youth Innovation Promotion Association,CASNational Natural Science Foundation of China,Grant No.12027803,U1731239Key Research Program of Frontier Sciences,CAS,Grant No.QYZDY-SSW-SLH008.
文摘Background The plastic scintillator detector(PSD)is one of the detectors in the high energy cosmic radiation detection(HERD)facility,which is designed for gamma-ray detection and a redundant charge measurement.Backsplash will lead to a decrease in PSD’s performance of gamma-ray detection and charge measurement,which should be carefully considered.Purpose Two preliminary segmentation schemes of the PSD and two veto strategies have been proposed to suppress the backsplash effect.In this paper,we focus on the influence of the backsplash caused by gamma rays.The gamma-ray trigger efficiency and identification efficiency were studied in the case of different cell sizes and veto strategies,which can provide guidance on the PSD design.Methods A Monte Carlo simulation based on Geant4 has been performed.To simplify the simulation,the PSD is segmented into 1 cm3 cubes which can be easily aggregated into cells with different sizes during analysis.Results and conclusion Side_Veto can be used as a baseline design of veto strategy,whereas Smart_Veto can be selected as an upgraded design.Both the PSD bar cell with a width of less than 11 cm and the PSD tile cell with a width of less than 20 cm can achieve a sufficiently high gamma-ray trigger efficiency(>80%),which realizes the primary goal of the PSD.Meanwhile,both the PSD bar cell with a width of less than 3 cm and the PSD tile cell with a width of less than 20 cm can ensure a sufficiently high gamma-ray identification efficiency(>80%)for photons up to 800 GeV.