This paper presents the first phase of design, analysis, and simulation for the klystron coaxial radio frequency（RF）output window. This study is motivated by 800 kW continuous wave（CW）, 650 MHz klystrons for the f...This paper presents the first phase of design, analysis, and simulation for the klystron coaxial radio frequency（RF）output window. This study is motivated by 800 kW continuous wave（CW）, 650 MHz klystrons for the future plan of circular electron–positron collider（CEPC） project. The RF window which is used in the klystron output section has a function to separate the klystron from the inner vacuum side to the outside, and high RF power propagates through the window with small power dissipation. Therefore, the window is a key component for the high power klystron. However, it is vulnerable to the high thermal stress and multipacting, so this paper presents the window design and analysis for these problems. The microwave design has been performed by using the computer simulation technology（CST） microwave studio and the return loss of the window has been established to be less than-90 d B. The multipacting simulation of the window has been carried out using MultiPac and CST particles studio. Through the multipacting analysis, it is shown that with thin coating of TiN, the multipacting effect has been suppressed effectively on the ceramic surface. The thermal analysis is carried out using ANSYS code and the temperature of alumina ceramic is lower than 310 K with water cooling.The design result successfully meets the requirement of the CEPC 650 MHz klystron. The manufacturing and high power test plan are also described in this paper.展开更多
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
Purpose A stripline kicker is required for Harbin Institute of Technology(HIT)10 MeV electron accelerator to scan electrons horizontally in two directions,and the maximum deflecting angle is 65 mrad.In this study,a 56...Purpose A stripline kicker is required for Harbin Institute of Technology(HIT)10 MeV electron accelerator to scan electrons horizontally in two directions,and the maximum deflecting angle is 65 mrad.In this study,a 560-mm-long stripline kicker was designed to achieve good field uniformity and odd mode impedance matching.Methods In order to reduce power reflections and meet field uniformity requirement,we optimized the cross section of the kicker main body.Design and optimization of the stripline kicker were finished by CST.Results The field uniformity is 2%in the 60 mm(x)×80 mm(y)region,as required.Considering impedance matching and manufacturing,the transmission odd mode impedance was finally chosen to 45Ω,which indicated a reflecting loss of less than−50 dB below 1 MHz.The maximum field is less than 7 MV/m with a maximum pulse voltage of±22 kV between the two electrodes when the electrons pass through the kicker.Conclusions The physical design of the stripline kicker has been finished,and the simulation results satisfied the requirements.展开更多
Purpose As the key component for the Higgs operating mode of Circular Electron-Positron Collider(CEPC),the electrostatic-magnetic deflectors are required by the double ring collider to separate the electron and the po...Purpose As the key component for the Higgs operating mode of Circular Electron-Positron Collider(CEPC),the electrostatic-magnetic deflectors are required by the double ring collider to separate the electron and the positron beams horizontally in the RF regions.The electric field is required to reach 2 MV/m with the vacuum pressure of less than 2×10^(−10) Torr.The deflectors make use of both electric and magnetic fields to deflect the beams.The incoming beam gets zero deflection,but the outgoing beam is deflected by the combined effect of the electric and magnetic forces.W and Z modes use the same cavities with H mode to save budget.The deflectors are large contributors to the overall beam impedance which is necessary to be reduced as much as possible.Methods The electric and magnetic field optimization has been performed by the Opera.The beam impedance study has been carried out using the Computer Simulation Technology(CST)particle studio.Results The shape of the electrode is optimized for a good electric field homogeneity(±0.05%)in 46 mm×40 mm region.The electric field and the magnetic field could be matched perfectly in the main body of the deflector by bending the elec-trodes and introducing magnetic field clamps and mirror plates.The beam loss factor decreases by about 20%via the intro-duction of ground electrodes and tapering ends.Conclusions The design results successfully meet the physical requirements,and the mechanical design has been finished.展开更多
Purpose For improving a beam quality of the linear accelerator and decreasing the influence of failure recovery on the accelerator available time,a high-voltage pulse modulator system is required to enhance the stabil...Purpose For improving a beam quality of the linear accelerator and decreasing the influence of failure recovery on the accelerator available time,a high-voltage pulse modulator system is required to enhance the stability of high-voltage pulses and maintain a low failure rate as well as a low failure recovery time,in order to implement a high-performance and stable operation.Methods This paper systematically analyzes the current status and operating conditions of the modulator equipment of BEPCII linear accelerator and simulates the typical parameters of the modulator considering the high-voltage DC charging power supply,DC charging cables and components and pulsed hydrogen thyratron.The technical route and retrofit scheme are proposed to decrease the failure rate and its recovery time.Results The stability of the high-voltage pulse modulator has increased by 1000 ppm,the failure rate has been decreased by two orders of magnitude,and the averaged recovery time from failures has been reduced by 94%as compared to the last operation period via implementing technical transformation with repeated exploration and experimental verification.展开更多
基金Project supported by Yifang Wang’s Science Studio of the Ten Thousand Talents Project,China
文摘This paper presents the first phase of design, analysis, and simulation for the klystron coaxial radio frequency（RF）output window. This study is motivated by 800 kW continuous wave（CW）, 650 MHz klystrons for the future plan of circular electron–positron collider（CEPC） project. The RF window which is used in the klystron output section has a function to separate the klystron from the inner vacuum side to the outside, and high RF power propagates through the window with small power dissipation. Therefore, the window is a key component for the high power klystron. However, it is vulnerable to the high thermal stress and multipacting, so this paper presents the window design and analysis for these problems. The microwave design has been performed by using the computer simulation technology（CST） microwave studio and the return loss of the window has been established to be less than-90 d B. The multipacting simulation of the window has been carried out using MultiPac and CST particles studio. Through the multipacting analysis, it is shown that with thin coating of TiN, the multipacting effect has been suppressed effectively on the ceramic surface. The thermal analysis is carried out using ANSYS code and the temperature of alumina ceramic is lower than 310 K with water cooling.The design result successfully meets the requirement of the CEPC 650 MHz klystron. The manufacturing and high power test plan are also described in this paper.
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.
文摘Purpose A stripline kicker is required for Harbin Institute of Technology(HIT)10 MeV electron accelerator to scan electrons horizontally in two directions,and the maximum deflecting angle is 65 mrad.In this study,a 560-mm-long stripline kicker was designed to achieve good field uniformity and odd mode impedance matching.Methods In order to reduce power reflections and meet field uniformity requirement,we optimized the cross section of the kicker main body.Design and optimization of the stripline kicker were finished by CST.Results The field uniformity is 2%in the 60 mm(x)×80 mm(y)region,as required.Considering impedance matching and manufacturing,the transmission odd mode impedance was finally chosen to 45Ω,which indicated a reflecting loss of less than−50 dB below 1 MHz.The maximum field is less than 7 MV/m with a maximum pulse voltage of±22 kV between the two electrodes when the electrons pass through the kicker.Conclusions The physical design of the stripline kicker has been finished,and the simulation results satisfied the requirements.
基金Thanks to National Key R&D Program of China(Grant No.2018YFA0404301)for the funding to this work.
文摘Purpose As the key component for the Higgs operating mode of Circular Electron-Positron Collider(CEPC),the electrostatic-magnetic deflectors are required by the double ring collider to separate the electron and the positron beams horizontally in the RF regions.The electric field is required to reach 2 MV/m with the vacuum pressure of less than 2×10^(−10) Torr.The deflectors make use of both electric and magnetic fields to deflect the beams.The incoming beam gets zero deflection,but the outgoing beam is deflected by the combined effect of the electric and magnetic forces.W and Z modes use the same cavities with H mode to save budget.The deflectors are large contributors to the overall beam impedance which is necessary to be reduced as much as possible.Methods The electric and magnetic field optimization has been performed by the Opera.The beam impedance study has been carried out using the Computer Simulation Technology(CST)particle studio.Results The shape of the electrode is optimized for a good electric field homogeneity(±0.05%)in 46 mm×40 mm region.The electric field and the magnetic field could be matched perfectly in the main body of the deflector by bending the elec-trodes and introducing magnetic field clamps and mirror plates.The beam loss factor decreases by about 20%via the intro-duction of ground electrodes and tapering ends.Conclusions The design results successfully meet the physical requirements,and the mechanical design has been finished.
文摘Purpose For improving a beam quality of the linear accelerator and decreasing the influence of failure recovery on the accelerator available time,a high-voltage pulse modulator system is required to enhance the stability of high-voltage pulses and maintain a low failure rate as well as a low failure recovery time,in order to implement a high-performance and stable operation.Methods This paper systematically analyzes the current status and operating conditions of the modulator equipment of BEPCII linear accelerator and simulates the typical parameters of the modulator considering the high-voltage DC charging power supply,DC charging cables and components and pulsed hydrogen thyratron.The technical route and retrofit scheme are proposed to decrease the failure rate and its recovery time.Results The stability of the high-voltage pulse modulator has increased by 1000 ppm,the failure rate has been decreased by two orders of magnitude,and the averaged recovery time from failures has been reduced by 94%as compared to the last operation period via implementing technical transformation with repeated exploration and experimental verification.
