The helical undulator is in high demand in synchrotron radiation facilities for circular polarization generation.Owing to the higher field strength provided by the superconducting undulator compared to the conventiona...The helical undulator is in high demand in synchrotron radiation facilities for circular polarization generation.Owing to the higher field strength provided by the superconducting undulator compared to the conventional permanent-magnet undulator,greater research efforts should be directed toward this area.The helical superconducting undulator holds great potential in synchrotron radiation facilities,especially in low-energy storage rings that seek circularly polarized radiation with the highest possible radiation flux.Following the successful development of planar superconducting undulators,the Institute of High Energy Physics conducted research and development for the helical superconducting undulator.A 0.5-m-long Deltatype superconducting undulator prototype was developed and tested.Detailed information on the design,fabrication,and cryogenic testing of the prototype is presented and discussed.展开更多
在上海硬X射线自由电子装置(Shanghai High Repetition rate XFEL and Extreme light facility,SHINE)中正在研制的超导波荡器样机磁隙小至5 mm、磁体长至4 m、磁场强至1.58 T。电流引线的冷却是样机正常工作的一个关键问题。因为该样...在上海硬X射线自由电子装置(Shanghai High Repetition rate XFEL and Extreme light facility,SHINE)中正在研制的超导波荡器样机磁隙小至5 mm、磁体长至4 m、磁场强至1.58 T。电流引线的冷却是样机正常工作的一个关键问题。因为该样机恒温器内没有制冷机冷头,利用外部独立的制冷系统输送进样机内部的低温氦气来冷却电流引线;利用冷屏中部的导冷组件来传递常导铜引线产生的热量;通过仿真优化了常导铜引线的热负载;在恒温器测试中设计了超导辅助带材以电连通高温超导引线(High Temperature Superconducting Current Lead,HTS)的冷端。从测试中得到HTS热端与低温氦气之间温差小于20 K,且所有电流引线在满负载下正常工作。结果表明:在该样机中利用低温氦气冷却管通过导冷方式来冷却电流引线的方案可行。展开更多
FLASH at DESY, Hamburg, Germany is the first free-electron laser(FEL) operating in the extreme ultraviolet(EUV)and soft x-ray wavelength range. FLASH is a user facility providing femtosecond short pulses with an unpre...FLASH at DESY, Hamburg, Germany is the first free-electron laser(FEL) operating in the extreme ultraviolet(EUV)and soft x-ray wavelength range. FLASH is a user facility providing femtosecond short pulses with an unprecedented peak and average brilliance, opening new scientific opportunities in many disciplines. The first call for user experiments has been launched in 2005. The FLASH linear accelerator is based on TESLA superconducting technology, providing several thousands of photon pulses per second to user experiments. Probing femtosecond-scale dynamics in atomic and molecular reactions using, for instance, a combination of x-ray and optical pulses in a pump and probe arrangement,as well as single-shot diffraction imaging of biological objects and molecules, are typical experiments performed at the facility. We give an overview of the FLASH facility, and describe the basic principles of the accelerator. Recently,FLASH has been extended by a second undulator beamline(FLASH2) operated in parallel to the first beamline, extending the capacity of the facility by a factor of two.展开更多
基金supported by the National Natural Science Foundation of China(No.E1113R5C10)。
文摘The helical undulator is in high demand in synchrotron radiation facilities for circular polarization generation.Owing to the higher field strength provided by the superconducting undulator compared to the conventional permanent-magnet undulator,greater research efforts should be directed toward this area.The helical superconducting undulator holds great potential in synchrotron radiation facilities,especially in low-energy storage rings that seek circularly polarized radiation with the highest possible radiation flux.Following the successful development of planar superconducting undulators,the Institute of High Energy Physics conducted research and development for the helical superconducting undulator.A 0.5-m-long Deltatype superconducting undulator prototype was developed and tested.Detailed information on the design,fabrication,and cryogenic testing of the prototype is presented and discussed.
文摘在上海硬X射线自由电子装置(Shanghai High Repetition rate XFEL and Extreme light facility,SHINE)中正在研制的超导波荡器样机磁隙小至5 mm、磁体长至4 m、磁场强至1.58 T。电流引线的冷却是样机正常工作的一个关键问题。因为该样机恒温器内没有制冷机冷头,利用外部独立的制冷系统输送进样机内部的低温氦气来冷却电流引线;利用冷屏中部的导冷组件来传递常导铜引线产生的热量;通过仿真优化了常导铜引线的热负载;在恒温器测试中设计了超导辅助带材以电连通高温超导引线(High Temperature Superconducting Current Lead,HTS)的冷端。从测试中得到HTS热端与低温氦气之间温差小于20 K,且所有电流引线在满负载下正常工作。结果表明:在该样机中利用低温氦气冷却管通过导冷方式来冷却电流引线的方案可行。
文摘FLASH at DESY, Hamburg, Germany is the first free-electron laser(FEL) operating in the extreme ultraviolet(EUV)and soft x-ray wavelength range. FLASH is a user facility providing femtosecond short pulses with an unprecedented peak and average brilliance, opening new scientific opportunities in many disciplines. The first call for user experiments has been launched in 2005. The FLASH linear accelerator is based on TESLA superconducting technology, providing several thousands of photon pulses per second to user experiments. Probing femtosecond-scale dynamics in atomic and molecular reactions using, for instance, a combination of x-ray and optical pulses in a pump and probe arrangement,as well as single-shot diffraction imaging of biological objects and molecules, are typical experiments performed at the facility. We give an overview of the FLASH facility, and describe the basic principles of the accelerator. Recently,FLASH has been extended by a second undulator beamline(FLASH2) operated in parallel to the first beamline, extending the capacity of the facility by a factor of two.
