In order to improve the performance of the Hefei Light Source （HLS）,in particular to get higher brilliance synchrotron radiation and increase the number of straight section insertion devices,an upgrade project calle...In order to improve the performance of the Hefei Light Source （HLS）,in particular to get higher brilliance synchrotron radiation and increase the number of straight section insertion devices,an upgrade project called HLSII will be launched soon.The storage ring lattice,which has a double bend achromatic structure with four periods,comprises eight dipoles,32 quadrupoles and 32 combined function sextupoles.The design and analysis of the magnets are shown in this paper,along with the optimization of the multipurpose combined function magnet,which consists of three magnets：skew quadrupole,horizontal dipole and vertical dipole,with the main sextupole magnet.This type of magnet is the first one that has been designed and used in China.The mechanical design and fabrication procedures for the magnets are also presented.展开更多
The electron–ion recombination for phosphorus-like^（112） Sn^（35＋）has been measured at the main cooler storage ring of the Heavy Ion Research Facility in Lanzhou, China, employing an electron–ion merged-beams te...The electron–ion recombination for phosphorus-like^（112） Sn^（35＋）has been measured at the main cooler storage ring of the Heavy Ion Research Facility in Lanzhou, China, employing an electron–ion merged-beams technique. The absolute total recombination rate coefficients for electron–ion collision energies from 0 e V–14 e V are presented. Theoretical calculations of recombination rate coefficients were performed using the Flexible Atomic Code to compare with the experimental results. The contributions of dielectronic recombination and trielectronic recombination on the experimental rate coefficients have been identified with the help of the theoretical calculation. The present results show that the trielectronic recombination has a substantial contribution to the measured electron–ion recombination spectrum of^（112）Sn^（35＋）. Although a reasonable agreement is found between the experimental and theoretical results the precise calculation of the electron–ion recombination rate coefficients for M-shell ions is still challengeable for the current theory.展开更多
The longitudinal Schottky spectra of a radio-frequency （RF） bunched and electron cooled 22Ne1~＋ ion beam at 70 MeV/u have been studied by a newly installed resonant Schottky pick-up at the experimental cooler stora...The longitudinal Schottky spectra of a radio-frequency （RF） bunched and electron cooled 22Ne1~＋ ion beam at 70 MeV/u have been studied by a newly installed resonant Schottky pick-up at the experimental cooler storage ring （CSRe）, at IMP. For an RF-bunched ion beam, a longitudinal momentum spread of Ap/p=l.6~lO-5 has been reached with less than 107 stored ions. The reduction of momentum spread compared with a coasting ion beam was observed from Schottky noise signal of the bunched ion beam. In order to prepare the future laser cooling experiment at the CSRe, the RF-bunching power was modulated at 25th, 50th and 75TM harmonic of the revolution frequency, effective bunching amplitudes were extracted from the Schottky spectrum analysis. Applications of Schottky noise for measuring beam lifetime with ultra-low intensity of ion beams are presented, and it is relevant to upcoming experiments on laser cooling of relativistic heavy ion beams and nuclear physics at the CSRe.展开更多
介绍了在兰州近代物理所建设的兰州重离子加速器冷却储存环外靶实验读出电子学预研系统中触发系统的需求特点以及基于PXI(PCI eXtensions for Instrumentation)总线规范进行触发系统的设计研究。触发系统根据高能物理实验特点将各探测...介绍了在兰州近代物理所建设的兰州重离子加速器冷却储存环外靶实验读出电子学预研系统中触发系统的需求特点以及基于PXI(PCI eXtensions for Instrumentation)总线规范进行触发系统的设计研究。触发系统根据高能物理实验特点将各探测器的电子学通道输入信号进行分级处理,产生携带触发信息的次级触发信号上传至上一级触发处理模块,并最终结合整个系统的各子触发信号,产生最终的触发信号发送至各子探测器系统用于触发判选。通过与探测器进行的联合调试,验证了基于PXI总线构架的触发系统的功能和指标,并为完整系统的设计和扩展提供了一个重要的参考。展开更多
基金Supported by National Natural Science Foundation of China (10905054,10979045,10875127)
文摘In order to improve the performance of the Hefei Light Source （HLS）,in particular to get higher brilliance synchrotron radiation and increase the number of straight section insertion devices,an upgrade project called HLSII will be launched soon.The storage ring lattice,which has a double bend achromatic structure with four periods,comprises eight dipoles,32 quadrupoles and 32 combined function sextupoles.The design and analysis of the magnets are shown in this paper,along with the optimization of the multipurpose combined function magnet,which consists of three magnets：skew quadrupole,horizontal dipole and vertical dipole,with the main sextupole magnet.This type of magnet is the first one that has been designed and used in China.The mechanical design and fabrication procedures for the magnets are also presented.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0402300)the Chinese Academy of Sciencesthe National Natural Science Foundation of China(Grant Nos.U1732133,11320101003,11611530684,and 11604003)
文摘The electron–ion recombination for phosphorus-like^（112） Sn^（35＋）has been measured at the main cooler storage ring of the Heavy Ion Research Facility in Lanzhou, China, employing an electron–ion merged-beams technique. The absolute total recombination rate coefficients for electron–ion collision energies from 0 e V–14 e V are presented. Theoretical calculations of recombination rate coefficients were performed using the Flexible Atomic Code to compare with the experimental results. The contributions of dielectronic recombination and trielectronic recombination on the experimental rate coefficients have been identified with the help of the theoretical calculation. The present results show that the trielectronic recombination has a substantial contribution to the measured electron–ion recombination spectrum of^（112）Sn^（35＋）. Although a reasonable agreement is found between the experimental and theoretical results the precise calculation of the electron–ion recombination rate coefficients for M-shell ions is still challengeable for the current theory.
基金National Natural Science Foundation of China (10921504)
文摘The longitudinal Schottky spectra of a radio-frequency （RF） bunched and electron cooled 22Ne1~＋ ion beam at 70 MeV/u have been studied by a newly installed resonant Schottky pick-up at the experimental cooler storage ring （CSRe）, at IMP. For an RF-bunched ion beam, a longitudinal momentum spread of Ap/p=l.6~lO-5 has been reached with less than 107 stored ions. The reduction of momentum spread compared with a coasting ion beam was observed from Schottky noise signal of the bunched ion beam. In order to prepare the future laser cooling experiment at the CSRe, the RF-bunching power was modulated at 25th, 50th and 75TM harmonic of the revolution frequency, effective bunching amplitudes were extracted from the Schottky spectrum analysis. Applications of Schottky noise for measuring beam lifetime with ultra-low intensity of ion beams are presented, and it is relevant to upcoming experiments on laser cooling of relativistic heavy ion beams and nuclear physics at the CSRe.
文摘介绍了在兰州近代物理所建设的兰州重离子加速器冷却储存环外靶实验读出电子学预研系统中触发系统的需求特点以及基于PXI(PCI eXtensions for Instrumentation)总线规范进行触发系统的设计研究。触发系统根据高能物理实验特点将各探测器的电子学通道输入信号进行分级处理,产生携带触发信息的次级触发信号上传至上一级触发处理模块,并最终结合整个系统的各子触发信号,产生最终的触发信号发送至各子探测器系统用于触发判选。通过与探测器进行的联合调试,验证了基于PXI总线构架的触发系统的功能和指标,并为完整系统的设计和扩展提供了一个重要的参考。
