Background The circular electron–positron collider(CEPC)is a double-ring collider proposed by Chinese scientists.It will be operated at centre-of-mass energy of 240,90,160 GeV and maybe also 360 GeV.Purpose The total...Background The circular electron–positron collider(CEPC)is a double-ring collider proposed by Chinese scientists.It will be operated at centre-of-mass energy of 240,90,160 GeV and maybe also 360 GeV.Purpose The total energy stored in the collider is up to 20 MJ.It is important to extract beams safely and not to damage the dump.In this paper,a dumping system including dilution kickers and absorber core with iron shielding is discussed.Methods The Monte Carlo code FLUKA is used to obtain the deposited energy and dose-equivalent distributions.The temperature rises are calculated assuming no heat conduction.Results Compared with the melting point and upper limit of dose equivalent,the magnets parameters are determined and the dimensions of the core and shielding are optimized.Conclusion The design of the dumping system meets the requirement that the energy stored in the collider can be absorbed safely.展开更多
Purpose The High Energy Photon Source(HEPS)is currently under construction in China and will be the brightest synchrotron radiation facility in the world.To solve the gas bremsstrahlung and synchrotron radiation hazar...Purpose The High Energy Photon Source(HEPS)is currently under construction in China and will be the brightest synchrotron radiation facility in the world.To solve the gas bremsstrahlung and synchrotron radiation hazard at HEPS beamlines,a comprehensive radiation study is performed.Method The Monte Carlo method is used to analyze the radiation field in the first optics enclosure at HEPS beamlines.First,the radiation sources including gas bremsstrahlung and synchrotron radiation are estimated.Then,the distribution of the radiation field in the hutch is calculated.Conservative parameters and a typical beamline geometry are used in the calculations.Finally,the shielding recommendations are summarized.Results and Conclusion In this paper,the considerations and bulk shielding design of the first optics enclosure at HEPS beamlines are described.The design satisfies the requirements of the radiation safety principles.展开更多
Purpose The high-energy photon source(HEPS)is the first fourth-generation light source under construction in China.It is designed to operate at an average current of 200 mA stored beam current with a top-up model at 6...Purpose The high-energy photon source(HEPS)is the first fourth-generation light source under construction in China.It is designed to operate at an average current of 200 mA stored beam current with a top-up model at 6 GeV energy.Considering the linac radiation shielding design,a suitable beam loss scenario,optimized thickness for the bulk shielding and detailed structure design for dumps should be proposed.In this paper,the beam loss scenarios were determined and categorized as normal;the dose limits were presented;using these scenarios and the dose limits,the thickness of the linac tunnel was calculated and detailed designs of the main beam dumps were established.The material selection and size setting of the low-power electron beam dump were discussed.Method The Monte Carlo code is a good choice to simulate the radiation analysis.And the iSHIELD11 was used to verify the simulation calculations.Result and conclusion The designs of the linac bulk shield and dumps satisfied the requirements of radiation protection.展开更多
Purpose To evaluate the prompt and induced dose rate in backscattering neutron hall for radiation protection and safety management.Method The dose rates were calculated by Monte Carlo code FLUKA,with the"multi-st...Purpose To evaluate the prompt and induced dose rate in backscattering neutron hall for radiation protection and safety management.Method The dose rates were calculated by Monte Carlo code FLUKA,with the"multi-step"simulation method based on traditional"two-step simulation"method.Conclusion Operation time of staff workers does not need to be restricted.But with the increase in beam power and irra-diation time,serious consideration might need to be taken as the dose rate of samples may be higher than the limit value.展开更多
文摘Background The circular electron–positron collider(CEPC)is a double-ring collider proposed by Chinese scientists.It will be operated at centre-of-mass energy of 240,90,160 GeV and maybe also 360 GeV.Purpose The total energy stored in the collider is up to 20 MJ.It is important to extract beams safely and not to damage the dump.In this paper,a dumping system including dilution kickers and absorber core with iron shielding is discussed.Methods The Monte Carlo code FLUKA is used to obtain the deposited energy and dose-equivalent distributions.The temperature rises are calculated assuming no heat conduction.Results Compared with the melting point and upper limit of dose equivalent,the magnets parameters are determined and the dimensions of the core and shielding are optimized.Conclusion The design of the dumping system meets the requirement that the energy stored in the collider can be absorbed safely.
文摘Purpose The High Energy Photon Source(HEPS)is currently under construction in China and will be the brightest synchrotron radiation facility in the world.To solve the gas bremsstrahlung and synchrotron radiation hazard at HEPS beamlines,a comprehensive radiation study is performed.Method The Monte Carlo method is used to analyze the radiation field in the first optics enclosure at HEPS beamlines.First,the radiation sources including gas bremsstrahlung and synchrotron radiation are estimated.Then,the distribution of the radiation field in the hutch is calculated.Conservative parameters and a typical beamline geometry are used in the calculations.Finally,the shielding recommendations are summarized.Results and Conclusion In this paper,the considerations and bulk shielding design of the first optics enclosure at HEPS beamlines are described.The design satisfies the requirements of the radiation safety principles.
基金Thiswork is supported by the high-energy photon source(HEPS)project,a major national science and technology infrastructure.
文摘Purpose The high-energy photon source(HEPS)is the first fourth-generation light source under construction in China.It is designed to operate at an average current of 200 mA stored beam current with a top-up model at 6 GeV energy.Considering the linac radiation shielding design,a suitable beam loss scenario,optimized thickness for the bulk shielding and detailed structure design for dumps should be proposed.In this paper,the beam loss scenarios were determined and categorized as normal;the dose limits were presented;using these scenarios and the dose limits,the thickness of the linac tunnel was calculated and detailed designs of the main beam dumps were established.The material selection and size setting of the low-power electron beam dump were discussed.Method The Monte Carlo code is a good choice to simulate the radiation analysis.And the iSHIELD11 was used to verify the simulation calculations.Result and conclusion The designs of the linac bulk shield and dumps satisfied the requirements of radiation protection.
基金supported by the National Key Research and Development Program of China(Project:2016YFA0401601)
文摘Purpose To evaluate the prompt and induced dose rate in backscattering neutron hall for radiation protection and safety management.Method The dose rates were calculated by Monte Carlo code FLUKA,with the"multi-step"simulation method based on traditional"two-step simulation"method.Conclusion Operation time of staff workers does not need to be restricted.But with the increase in beam power and irra-diation time,serious consideration might need to be taken as the dose rate of samples may be higher than the limit value.
