针对应用于硼中子俘获治疗的加速器中子源的束流偏转问题,为其低能束流传输线部分设计了一套斩束器,通过理论计算与软件模拟,验证方案的可行性。为了解决斩波器电场强度不均匀问题,引入圆弧电极设计结构,微波工作室(CST Studio Suite)...针对应用于硼中子俘获治疗的加速器中子源的束流偏转问题,为其低能束流传输线部分设计了一套斩束器,通过理论计算与软件模拟,验证方案的可行性。为了解决斩波器电场强度不均匀问题,引入圆弧电极设计结构,微波工作室(CST Studio Suite)模拟仿真表明其具有更好的电场分布均匀性。发展了基于Python程序的CST与TraceWin联合束流动力学模拟,结果表明设计的斩波器能够高效率地实现束流偏转功能,设计方案具有良好的实际应用价值和意义。展开更多
In response to the increasing demand for hadron therapy facilities,significant efforts have been directed toward enhancing the performance of high-gradient and high-transmission injectors for light ion beams.For carbo...In response to the increasing demand for hadron therapy facilities,significant efforts have been directed toward enhancing the performance of high-gradient and high-transmission injectors for light ion beams.For carbon ion irradiations,which offer greater radiobiological efficiency in tumor treatment,recent research has focused on developing high-production sources of fully stripped C^(6+)ions and highly compact,high-frequency RFQ cavities.This study explores the design possibilities of a carbon ion acceleration section using 750 MHz Interdigital H-mode Drift Tube Linacs(IH-DTLs)as a high-efficiency solution for accelerating ions in the 5-10 MeV per nucleon energy range.A particle-tracking routine based on the TRAVEL code was developed to design the acceleration line through a tailored KONUS-type configuration.Three design solutions were proposed and compared,exploring different alternatives regarding the use of a MEBT to match the output beam phase space of the RFQ to the optics of the line,as well as varying considerations for magnetic systems to focus the beam.Additionally,the compatibility of the proposed solutions with the existing design of the carbon ion bent-linac for hadron therapy was assessed.展开更多
Electron beam injectors are pivotal components of large-scale scientific instruments,such as synchrotron radiation sources,free-electron lasers,and electron-positron colliders.The quality of the electron beam produced...Electron beam injectors are pivotal components of large-scale scientific instruments,such as synchrotron radiation sources,free-electron lasers,and electron-positron colliders.The quality of the electron beam produced by the injector critically influences the performance of the entire accelerator-based scientific research apparatus.The injectors of such facilities usually use photocathode and thermionic-cathode electron guns.Although the photocathode injector can produce electron beams of excellent quality,its associated laser system is massive and intricate.The thermionic-cathode electron gun,especially the gridded electron gun injector,has a simple structure capable of generating numerous electron beams.However,its emittance is typically high.In this study,methods to reduce beam emittance are explored through a comprehensive analysis of various grid structures and preliminary design results,examining the evolution of beam phase space at different grid positions.An optimization method for reducing the emittance of a gridded thermionic-cathode electron gun is proposed through theoretical derivation,electromagnetic-field simulation,and beam-dynamics simulation.A 50%reduction in emittance was achieved for a 50 keV,1.7 A electron gun,laying the foundation for the subsequent design of a high-current,low-emittance injector.展开更多
The Southern Advanced Photon Source(SAPS)is a diffraction-limited synchrotron light source under design,which employs longitudinal injection as its primary injection scheme.This kind of injection scheme requires that ...The Southern Advanced Photon Source(SAPS)is a diffraction-limited synchrotron light source under design,which employs longitudinal injection as its primary injection scheme.This kind of injection scheme requires that the injected beam has a short bunch length and low emittance,and the preferred injector should offer high stability and low cost.Therefore,an injector based on a booster synchrotron was developed.The proposed injector includes a 250 MeV linac,a booster synchrotron that ramps the beam energy to 3.5 GeV,and two beam transport lines to ensure efficient beam delivery and beam quality preservation.The linac utilizes a thermionic high-voltage DC gun for reliable operation and features a bunching system with an advanced focusing system to preserve the emittance.To meet the injection requirements of the SAPS,a comprehensive design for the booster has been conducted.The booster synchrotron employs a threefold lattice structure,incorporating modified theoretical minimum emittance cells with a small momentum compaction factor and a high voltage to achieve an emittance of 3.98 nm rad and a bunch length of 4.8 mm.The injector has the potential to deliver a high charge,reducing the injection period of the storage ring to less than 1 min.Simulations demonstrated the expected performance,with a transmission efficiency of 90%,confirming its capability to meet the injection requirement of the SAPS storage ring.This design offers a stable and efficient solution for the SAPS.展开更多
快循环同步加速器的二极磁铁和四极磁铁磁场变化过快可能会在常规真空管道中引发严重的涡流效应,针对这一问题国内外提出了多种新型真空管道方案,例如陶瓷管道、外侧加筋超薄壁不锈钢管道以及陶瓷内衬超薄壁不锈钢管道等等。最近中国科...快循环同步加速器的二极磁铁和四极磁铁磁场变化过快可能会在常规真空管道中引发严重的涡流效应,针对这一问题国内外提出了多种新型真空管道方案,例如陶瓷管道、外侧加筋超薄壁不锈钢管道以及陶瓷内衬超薄壁不锈钢管道等等。最近中国科学院近代物理研究所(IMP)的HIAF工程团队提出了用钛合金内衬代替陶瓷内衬的方案,形成的钛合金内衬超薄壁不锈钢真空管道横向孔径更小,出气率更低,制造成本也更少。但钛合金内衬真空管道将成为HIAF装置的环形主加速器BRing上重要的束流耦合阻抗源。其中四极铁钛合金内衬真空管道引入的阻抗及其影响,以及相应阻抗减小设计的有效性尚待评估。本工作首先在模拟软件CST studio suite中使用两种不同的方法分别对各种规格的四极铁钛合金内衬真空管道的阻抗进行了模拟,两种方法给出了互相接近的结果。然后在此基础上计算了换用钛合金内衬真空管道后BRing的全环横向阻抗。进一步地,本工作结合全环阻抗数据利用Vlasov solver计算了换用钛合金内衬真空管道后BRing上^(78)Kr^(19+)束在不同流强下的模式频率移动。发现二极磁铁和四极磁铁钛合金内衬真空管道采用阻抗减小设计前,BRing上^(78)Kr^(19+)束发生横向模耦合不稳定性的流强阈值为2.7×10^(11)ppp,低于BRing上^(78)Kr^(19+)束的设计流强(3×10^(11)ppp)。采用阻抗减小设计后,^(78)Kr^(19+)束发生横向模耦合不稳定性的流强阈值会提升到4.4×10^(11)ppp。这表明二极铁和四极铁钛合金内衬真空管道的阻抗减小设计是有效的。仅从横向宽带束流耦合阻抗的角度来看,BRing二极磁铁和四极磁铁上用钛合金内衬真空管道替代陶瓷内衬真空管道是可行的。展开更多
文摘针对应用于硼中子俘获治疗的加速器中子源的束流偏转问题,为其低能束流传输线部分设计了一套斩束器,通过理论计算与软件模拟,验证方案的可行性。为了解决斩波器电场强度不均匀问题,引入圆弧电极设计结构,微波工作室(CST Studio Suite)模拟仿真表明其具有更好的电场分布均匀性。发展了基于Python程序的CST与TraceWin联合束流动力学模拟,结果表明设计的斩波器能够高效率地实现束流偏转功能,设计方案具有良好的实际应用价值和意义。
基金Project co-funded by European Union in the context of the precommercial public procurement of RD services managed by CDTI E.P.Eco-funded by the European Regional Development Fund(ERDF)as part of the project for the development of a Compact Linear Accelerator for Hadrontherapy,Exp.CPP 03/2023 AB(DCCPI/OCPI)。
文摘In response to the increasing demand for hadron therapy facilities,significant efforts have been directed toward enhancing the performance of high-gradient and high-transmission injectors for light ion beams.For carbon ion irradiations,which offer greater radiobiological efficiency in tumor treatment,recent research has focused on developing high-production sources of fully stripped C^(6+)ions and highly compact,high-frequency RFQ cavities.This study explores the design possibilities of a carbon ion acceleration section using 750 MHz Interdigital H-mode Drift Tube Linacs(IH-DTLs)as a high-efficiency solution for accelerating ions in the 5-10 MeV per nucleon energy range.A particle-tracking routine based on the TRAVEL code was developed to design the acceleration line through a tailored KONUS-type configuration.Three design solutions were proposed and compared,exploring different alternatives regarding the use of a MEBT to match the output beam phase space of the RFQ to the optics of the line,as well as varying considerations for magnetic systems to focus the beam.Additionally,the compatibility of the proposed solutions with the existing design of the carbon ion bent-linac for hadron therapy was assessed.
基金supported by the Hundred-person Program of Chinese Academy of Sciences and the National Natural Science Foundation of China(No.11905074).
文摘Electron beam injectors are pivotal components of large-scale scientific instruments,such as synchrotron radiation sources,free-electron lasers,and electron-positron colliders.The quality of the electron beam produced by the injector critically influences the performance of the entire accelerator-based scientific research apparatus.The injectors of such facilities usually use photocathode and thermionic-cathode electron guns.Although the photocathode injector can produce electron beams of excellent quality,its associated laser system is massive and intricate.The thermionic-cathode electron gun,especially the gridded electron gun injector,has a simple structure capable of generating numerous electron beams.However,its emittance is typically high.In this study,methods to reduce beam emittance are explored through a comprehensive analysis of various grid structures and preliminary design results,examining the evolution of beam phase space at different grid positions.An optimization method for reducing the emittance of a gridded thermionic-cathode electron gun is proposed through theoretical derivation,electromagnetic-field simulation,and beam-dynamics simulation.A 50%reduction in emittance was achieved for a 50 keV,1.7 A electron gun,laying the foundation for the subsequent design of a high-current,low-emittance injector.
基金supported by the Guangdong Basic and Applied Basic Research Foundation,China(No.2021B1515140007).
文摘The Southern Advanced Photon Source(SAPS)is a diffraction-limited synchrotron light source under design,which employs longitudinal injection as its primary injection scheme.This kind of injection scheme requires that the injected beam has a short bunch length and low emittance,and the preferred injector should offer high stability and low cost.Therefore,an injector based on a booster synchrotron was developed.The proposed injector includes a 250 MeV linac,a booster synchrotron that ramps the beam energy to 3.5 GeV,and two beam transport lines to ensure efficient beam delivery and beam quality preservation.The linac utilizes a thermionic high-voltage DC gun for reliable operation and features a bunching system with an advanced focusing system to preserve the emittance.To meet the injection requirements of the SAPS,a comprehensive design for the booster has been conducted.The booster synchrotron employs a threefold lattice structure,incorporating modified theoretical minimum emittance cells with a small momentum compaction factor and a high voltage to achieve an emittance of 3.98 nm rad and a bunch length of 4.8 mm.The injector has the potential to deliver a high charge,reducing the injection period of the storage ring to less than 1 min.Simulations demonstrated the expected performance,with a transmission efficiency of 90%,confirming its capability to meet the injection requirement of the SAPS storage ring.This design offers a stable and efficient solution for the SAPS.
文摘光束线站真空安全联锁是保障同步辐射光源储存环的运行安全与线站关键设备安全的重要系统。文章阐述了合肥光源新建成的金华光束线站真空安全联锁系统的最新设计方法。基于新型的高性能可编程控制器PLC(Programmable Logic Controller)和开放的软件平台EPICS 7(Experimental Physics and Industrial Control System)分布式控制系统架构,同时采用虚拟化技术,开发了全新的光束线站真空安全联锁系统。在系统远控的OPI界面开发上,采用Python脚本一键自动生成,提高了系统开发效率。此次设计在确保系统安全性和可靠性的同时,系统的性能以及用户人机交互的体验都得以提升。这些设计方法为正在建设的合肥先进光源的光束线站控制提供了技术储备和实践经验。
文摘快循环同步加速器的二极磁铁和四极磁铁磁场变化过快可能会在常规真空管道中引发严重的涡流效应,针对这一问题国内外提出了多种新型真空管道方案,例如陶瓷管道、外侧加筋超薄壁不锈钢管道以及陶瓷内衬超薄壁不锈钢管道等等。最近中国科学院近代物理研究所(IMP)的HIAF工程团队提出了用钛合金内衬代替陶瓷内衬的方案,形成的钛合金内衬超薄壁不锈钢真空管道横向孔径更小,出气率更低,制造成本也更少。但钛合金内衬真空管道将成为HIAF装置的环形主加速器BRing上重要的束流耦合阻抗源。其中四极铁钛合金内衬真空管道引入的阻抗及其影响,以及相应阻抗减小设计的有效性尚待评估。本工作首先在模拟软件CST studio suite中使用两种不同的方法分别对各种规格的四极铁钛合金内衬真空管道的阻抗进行了模拟,两种方法给出了互相接近的结果。然后在此基础上计算了换用钛合金内衬真空管道后BRing的全环横向阻抗。进一步地,本工作结合全环阻抗数据利用Vlasov solver计算了换用钛合金内衬真空管道后BRing上^(78)Kr^(19+)束在不同流强下的模式频率移动。发现二极磁铁和四极磁铁钛合金内衬真空管道采用阻抗减小设计前,BRing上^(78)Kr^(19+)束发生横向模耦合不稳定性的流强阈值为2.7×10^(11)ppp,低于BRing上^(78)Kr^(19+)束的设计流强(3×10^(11)ppp)。采用阻抗减小设计后,^(78)Kr^(19+)束发生横向模耦合不稳定性的流强阈值会提升到4.4×10^(11)ppp。这表明二极铁和四极铁钛合金内衬真空管道的阻抗减小设计是有效的。仅从横向宽带束流耦合阻抗的角度来看,BRing二极磁铁和四极磁铁上用钛合金内衬真空管道替代陶瓷内衬真空管道是可行的。
