Low temperature plasma has become an essential tool for the surface treatment of SRF cavities due to its rich variety of active particles,such as electrons,ions,and free radicals.On the one hand,we have mastered the p...Low temperature plasma has become an essential tool for the surface treatment of SRF cavities due to its rich variety of active particles,such as electrons,ions,and free radicals.On the one hand,we have mastered the plasma optimization strategy inside SRF cavities,including the plasma electrodes’design and plasma distribution(Fig.1).On the other hand,the evolutionary laws of active particles in plasma have been studied(Fig.2),and successfully explain the decay mechanism of hydrocarbons in SRF cavities.These findings have already provided a valuable reference for the cleaning and coating of SRF cavities.展开更多
The reactive oxygen plasma cleaning was proved an efficient method to decrease the field emission effect of the HWR superconducting cavities on the vertical test platform.
RF Surface Technology Research Group was founded in August 2019.It was evolved from the former Supercon-ducting Radio Frequency(SRF)research group of Linac center.The primary research topics will be presented in this ...RF Surface Technology Research Group was founded in August 2019.It was evolved from the former Supercon-ducting Radio Frequency(SRF)research group of Linac center.The primary research topics will be presented in this report.展开更多
After many years of worldwide exploration and improvement of the post treatment process,niobium(Nb)cavities are now approaching their fundamental limits both in terms of maximum acceleration field and in terms of surf...After many years of worldwide exploration and improvement of the post treatment process,niobium(Nb)cavities are now approaching their fundamental limits both in terms of maximum acceleration field and in terms of surface resistance at typical operating temperatures.展开更多
In 2018,detailed studies on RF induced plasma for the in-situ cleaning of the HWR cavity were conducted to improve the performance of the cavity.For the purpose of cleaning the HWR cavities in cryomodule,an apparatus ...In 2018,detailed studies on RF induced plasma for the in-situ cleaning of the HWR cavity were conducted to improve the performance of the cavity.For the purpose of cleaning the HWR cavities in cryomodule,an apparatus for the discharge experiments was designed at room temperature,which duplicates the assembly of cavities inside cryomodule,where the FPC was used for power coupling.展开更多
Field emission occurred in superconducting radio-frequency(SRF)cavities is the major obstacle of the accelerators operating at high gradient,which partly caused by the inner surface contamination,such as the hydrocarb...Field emission occurred in superconducting radio-frequency(SRF)cavities is the major obstacle of the accelerators operating at high gradient,which partly caused by the inner surface contamination,such as the hydrocarbons and the absorbed residual gas.The plasma processing can be an effective method to solve the field emission issues.The properties of low temperature glow discharge,which was argon plasma with the chemically reactive oxygen,were investigated for the SRF cavities used for CADS project.展开更多
功率耦合器是粒子加速腔射频功率馈送的关键部件。耦合器在安装至加速腔之前,必须进行常温高功率测试和锻炼,以检验加工工艺和设计指标,提高其射频性能。详细介绍了中国科学院近代物理研究所ADS25 Me V加速器样机162.5 MHz耦合器测试平...功率耦合器是粒子加速腔射频功率馈送的关键部件。耦合器在安装至加速腔之前,必须进行常温高功率测试和锻炼,以检验加工工艺和设计指标,提高其射频性能。详细介绍了中国科学院近代物理研究所ADS25 Me V加速器样机162.5 MHz耦合器测试平台的改进设计。针对原有接触式测试锻炼方式的不足,提出非接触式测试锻炼方案。对耦合器测试锻炼过程进行了物理抽象,采用理论模拟的方法分析测试腔体功率传输。基于分析结果设计了低损耗、宽通带、多用途的非接触式耦合器测试腔体。该腔体可实现20 k W测试功率下60 W左右的腔体损耗和15 MHz-3 d B带宽。展开更多
文摘Low temperature plasma has become an essential tool for the surface treatment of SRF cavities due to its rich variety of active particles,such as electrons,ions,and free radicals.On the one hand,we have mastered the plasma optimization strategy inside SRF cavities,including the plasma electrodes’design and plasma distribution(Fig.1).On the other hand,the evolutionary laws of active particles in plasma have been studied(Fig.2),and successfully explain the decay mechanism of hydrocarbons in SRF cavities.These findings have already provided a valuable reference for the cleaning and coating of SRF cavities.
文摘The reactive oxygen plasma cleaning was proved an efficient method to decrease the field emission effect of the HWR superconducting cavities on the vertical test platform.
文摘RF Surface Technology Research Group was founded in August 2019.It was evolved from the former Supercon-ducting Radio Frequency(SRF)research group of Linac center.The primary research topics will be presented in this report.
文摘After many years of worldwide exploration and improvement of the post treatment process,niobium(Nb)cavities are now approaching their fundamental limits both in terms of maximum acceleration field and in terms of surface resistance at typical operating temperatures.
文摘In 2018,detailed studies on RF induced plasma for the in-situ cleaning of the HWR cavity were conducted to improve the performance of the cavity.For the purpose of cleaning the HWR cavities in cryomodule,an apparatus for the discharge experiments was designed at room temperature,which duplicates the assembly of cavities inside cryomodule,where the FPC was used for power coupling.
文摘Field emission occurred in superconducting radio-frequency(SRF)cavities is the major obstacle of the accelerators operating at high gradient,which partly caused by the inner surface contamination,such as the hydrocarbons and the absorbed residual gas.The plasma processing can be an effective method to solve the field emission issues.The properties of low temperature glow discharge,which was argon plasma with the chemically reactive oxygen,were investigated for the SRF cavities used for CADS project.
文摘功率耦合器是粒子加速腔射频功率馈送的关键部件。耦合器在安装至加速腔之前,必须进行常温高功率测试和锻炼,以检验加工工艺和设计指标,提高其射频性能。详细介绍了中国科学院近代物理研究所ADS25 Me V加速器样机162.5 MHz耦合器测试平台的改进设计。针对原有接触式测试锻炼方式的不足,提出非接触式测试锻炼方案。对耦合器测试锻炼过程进行了物理抽象,采用理论模拟的方法分析测试腔体功率传输。基于分析结果设计了低损耗、宽通带、多用途的非接触式耦合器测试腔体。该腔体可实现20 k W测试功率下60 W左右的腔体损耗和15 MHz-3 d B带宽。
