Correction to:Radiation Detection Technology and Methods(2024)8:1-1105.https://doi.org/10.1007/s41605-024-00463-y.In this article all authors name was missing in the springer link.It has been corrected.The original ar...Correction to:Radiation Detection Technology and Methods(2024)8:1-1105.https://doi.org/10.1007/s41605-024-00463-y.In this article all authors name was missing in the springer link.It has been corrected.The original article has been corrected.展开更多
The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 3...The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.展开更多
Background The Circular Electron Positron Collider(CEPC)is a large international scientific facility proposed to study the Higgs boson in great detail.It requires state-of-the-art detectors,including extremely precise...Background The Circular Electron Positron Collider(CEPC)is a large international scientific facility proposed to study the Higgs boson in great detail.It requires state-of-the-art detectors,including extremely precise vertexing and tracking devices,such as a silicon vertex detector.Purpose Silicon vertex detector with the precision required by the CEPC has never been built before and needs extensive research and development.This paper describes the mechanical design of a vertex detector prototype being built to explore the required technologies and the major challenges.Methods The exceptional high spatial resolution of the CEPC vertex detector is achievable only with a detector of extremely low mass to limit particle scattering.This paper proposes a mechanical design for the vertex detector prototype,highlighting the choice of low-mass materials,the analysis of support structures,the solution of detector cooling issues,and the drafts of procedures for detector assembly.Results The ultra-light support of the ladder(a structural unit of the CEPC vertex detector prototype),which is mainly made of carbon fiber reinforced polymer composite,has been designed.The fabrication process has also been verified.Global supporting and cooling method of the vertex detector prototype has been designed and chosen with results from finite element analysis and computational fluid dynamics simulations.Complete assembly and installation schemes for the prototype have been developed,and the respective tooling has also been designed.The performance of the vertex detector prototype,using this low-mass mechanical structure,was demonstrated with fast simulation to closely meet the CEPC physics requirement.展开更多
Background The circular electron positron collider(CEPC)was proposed as a future Higgs/Z factory.A sampling calo-rimeter with scintillator-tungsten sandwich structure(ScW)is selected as one of the electromagnetic calo...Background The circular electron positron collider(CEPC)was proposed as a future Higgs/Z factory.A sampling calo-rimeter with scintillator-tungsten sandwich structure(ScW)is selected as one of the electromagnetic calorimeter(ECAL)options.Its active layers consist of plastic scintillator strip units with a thickness of 2 mm and a size of 5×45 mm2,read out by silicon photomultipliers(SiPM).Purpose The light output has non-uniformity along the length direction of the scintillator strip,which affects the resolution of the ScW ECAL.It is necessary to control the non-uniformity to a low level.Methods We present the optimization of the scintillator units to improve the uniformity of the light output,including the light output distribution of the scintillator strips with different SiPM coupling configurations,and the impact of the coupling groove shape and dimension on the light output uniformity.Results and conclusion The results show that the non-uniformity of the scintillator unit with a runway-shaped coupling groove at the bottom-center of the strip can achieve 4%without reduction in the light output.Compared to the case of non-uniformity before optimization,the optimized uniformity improves the boson mass resolution about 23%based on the reconstruction of Higgs→γγ,which is comparable to the perfect homogeneous case.展开更多
Purpose In the upgrade study of the BESII inner drift chamber,a two-layer concentric cylindrical silicon pixel detector is proposed,which will be positioned between the beam pipe and the inner drift chamber.Method The...Purpose In the upgrade study of the BESII inner drift chamber,a two-layer concentric cylindrical silicon pixel detector is proposed,which will be positioned between the beam pipe and the inner drift chamber.Method The detector consists of CMOS pixel sensors at wafer scale using chip stitching technology.The chips are thinned to a flexible thickness of about 50μm.PMI foams are used as spacers and auxiliary support between the adjacent layers,enabling the first layer of the detector to be put as close to the central beam pipe as possible.The detector structure has been optimized through finite-element analysis(FEA).Result The material budget of the detector has been reduced to about 0.077%Xo per layer.The maximum deformation of the chip edge has been controlled to±80μm after bending,and the roundness is about 100μm,which verifies the feasibility of the cylindrical detector prototype structure.In addition,the wire bonding process for the cylindrical silicon pixel detector has been tested and preliminarily validated.Conclusion This study validates the process flow for the development of large-area cylindrical detectors based on stitching technology,laying a foundation for the smooth progress of subsequent study.展开更多
文摘Correction to:Radiation Detection Technology and Methods(2024)8:1-1105.https://doi.org/10.1007/s41605-024-00463-y.In this article all authors name was missing in the springer link.It has been corrected.The original article has been corrected.
基金support from diverse funding sources,including the National Key Program for S&T Research and Development of the Ministry of Science and Technology(MOST),Yifang Wang's Science Studio of the Ten Thousand Talents Project,the CAS Key Foreign Cooperation Grant,the National Natural Science Foundation of China(NSFC)Beijing Municipal Science&Technology Commission,the CAS Focused Science Grant,the IHEP Innovation Grant,the CAS Lead Special Training Programthe CAS Center for Excellence in Particle Physics,the CAS International Partnership Program,and the CAS/SAFEA International Partnership Program for Creative Research Teams.
文摘The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.
基金supported and financed by the National Key Research and Development Program of China under Grant No.2018YFA0404302
文摘Background The Circular Electron Positron Collider(CEPC)is a large international scientific facility proposed to study the Higgs boson in great detail.It requires state-of-the-art detectors,including extremely precise vertexing and tracking devices,such as a silicon vertex detector.Purpose Silicon vertex detector with the precision required by the CEPC has never been built before and needs extensive research and development.This paper describes the mechanical design of a vertex detector prototype being built to explore the required technologies and the major challenges.Methods The exceptional high spatial resolution of the CEPC vertex detector is achievable only with a detector of extremely low mass to limit particle scattering.This paper proposes a mechanical design for the vertex detector prototype,highlighting the choice of low-mass materials,the analysis of support structures,the solution of detector cooling issues,and the drafts of procedures for detector assembly.Results The ultra-light support of the ladder(a structural unit of the CEPC vertex detector prototype),which is mainly made of carbon fiber reinforced polymer composite,has been designed.The fabrication process has also been verified.Global supporting and cooling method of the vertex detector prototype has been designed and chosen with results from finite element analysis and computational fluid dynamics simulations.Complete assembly and installation schemes for the prototype have been developed,and the respective tooling has also been designed.The performance of the vertex detector prototype,using this low-mass mechanical structure,was demonstrated with fast simulation to closely meet the CEPC physics requirement.
基金supported by National Key Programme for S&T Research and Development(Grant No.2016YFA0400400)National Natural Science Foundation of China(Grant No.11675196)supported in part by the CAS Centre for Excellence in Particle Physics(CCEPP)
文摘Background The circular electron positron collider(CEPC)was proposed as a future Higgs/Z factory.A sampling calo-rimeter with scintillator-tungsten sandwich structure(ScW)is selected as one of the electromagnetic calorimeter(ECAL)options.Its active layers consist of plastic scintillator strip units with a thickness of 2 mm and a size of 5×45 mm2,read out by silicon photomultipliers(SiPM).Purpose The light output has non-uniformity along the length direction of the scintillator strip,which affects the resolution of the ScW ECAL.It is necessary to control the non-uniformity to a low level.Methods We present the optimization of the scintillator units to improve the uniformity of the light output,including the light output distribution of the scintillator strips with different SiPM coupling configurations,and the impact of the coupling groove shape and dimension on the light output uniformity.Results and conclusion The results show that the non-uniformity of the scintillator unit with a runway-shaped coupling groove at the bottom-center of the strip can achieve 4%without reduction in the light output.Compared to the case of non-uniformity before optimization,the optimized uniformity improves the boson mass resolution about 23%based on the reconstruction of Higgs→γγ,which is comparable to the perfect homogeneous case.
基金supported by the National Natural Science Foundation of China(No.U2032203).
文摘Purpose In the upgrade study of the BESII inner drift chamber,a two-layer concentric cylindrical silicon pixel detector is proposed,which will be positioned between the beam pipe and the inner drift chamber.Method The detector consists of CMOS pixel sensors at wafer scale using chip stitching technology.The chips are thinned to a flexible thickness of about 50μm.PMI foams are used as spacers and auxiliary support between the adjacent layers,enabling the first layer of the detector to be put as close to the central beam pipe as possible.The detector structure has been optimized through finite-element analysis(FEA).Result The material budget of the detector has been reduced to about 0.077%Xo per layer.The maximum deformation of the chip edge has been controlled to±80μm after bending,and the roundness is about 100μm,which verifies the feasibility of the cylindrical detector prototype structure.In addition,the wire bonding process for the cylindrical silicon pixel detector has been tested and preliminarily validated.Conclusion This study validates the process flow for the development of large-area cylindrical detectors based on stitching technology,laying a foundation for the smooth progress of subsequent study.
