A new linear accelerator system,called the SSC-Linac injector,is being designed at HIRFL （the heavy ion research facility of Lanzhou）.As part of the SSC-Linac,the medium energy beam transport （MEBT） consists of se...A new linear accelerator system,called the SSC-Linac injector,is being designed at HIRFL （the heavy ion research facility of Lanzhou）.As part of the SSC-Linac,the medium energy beam transport （MEBT） consists of seven magnetic quadrupoles,a re-buncher and a diagnose box.The total length of this segment is about 1.75 m.The beam dynamics simulation in MEBT has been studied using the TRACK 3D particle-in-cell code,and the simulation result shows that the beam accelerated from the radio frequency quadrupole （RFQ） matches well with the acceptance of the following drift tube linac （DTL） in both the transverse and longitudinal phase spaces,and that most of the particles can be captured by the final sector focusing cyclotron for further acceleration.The longitudinal emittance of the RFQ and the longitudinal acceptance of the DTL was calculated in detail,and a multi-particle beam dynamics simulation from the ion source to the end of the DTL was done to verify the original design.展开更多
A new SSC-linac system （injector into separated sector cyclotron） is being designed in the HIRFL （heavy ion research facility of Lanzhou）. As part of SSC-Linac, the LEBT （low energy beam transport） consists of s...A new SSC-linac system （injector into separated sector cyclotron） is being designed in the HIRFL （heavy ion research facility of Lanzhou）. As part of SSC-Linac, the LEBT （low energy beam transport） consists of seven solenoids, four quadrupoles, a bending magnet and an extra multi-harmonic buncher. The total length of this segment is about 7 meters. The beam dynamics in this LEBT has been studied using three-dimensional PIC （particle-in-cell） code BEAMPATH. The simulation results show that the continuous beam from the ion source is first well analyzed by a charge-to-mass selection system, and the beam of the selected charge-to-mass ratio is then efficiently pre-bunched by a multi-harmonic buncher and optimally matched into the RFQ （radio frequency quadrupole） for further acceleration. The principles and effects of the solenoid collimation channel are discussed, and it could limit the beam emittance by changing the aperture size.展开更多
将滑模极值搜索算法引入基于腔体反射信号的SSC-LINAC射频四极场加速器(Radio Frequency Quadrupole, RFQ)腔体频率稳定系统设计中,结合Lyapunov稳定性理论和SSC-LINAC RFQ高频系统的特点,对滑模极值搜索算法的控制增益和参考信号进行改...将滑模极值搜索算法引入基于腔体反射信号的SSC-LINAC射频四极场加速器(Radio Frequency Quadrupole, RFQ)腔体频率稳定系统设计中,结合Lyapunov稳定性理论和SSC-LINAC RFQ高频系统的特点,对滑模极值搜索算法的控制增益和参考信号进行改进;通过求解微分方程,得到腔体反射信号关于时间和调谐杆位置的函数。通过软件仿真和设计硬件系统,对基于滑模极值搜索算法的调谐过程进行仿真与实际测试,结果显示,所设计的频率稳定系统能够在较短时间内实现SSC-LINAC RFQ腔体功率自动馈入过程且频率稳定度满足设计指标要求,通过了长时间稳定性试验。证明了将滑模极值搜索算法应用于高频谐振腔调谐工作的可行性。展开更多
基金Supported by National Natural Science Foundation of China (10635090)
文摘A new linear accelerator system,called the SSC-Linac injector,is being designed at HIRFL （the heavy ion research facility of Lanzhou）.As part of the SSC-Linac,the medium energy beam transport （MEBT） consists of seven magnetic quadrupoles,a re-buncher and a diagnose box.The total length of this segment is about 1.75 m.The beam dynamics simulation in MEBT has been studied using the TRACK 3D particle-in-cell code,and the simulation result shows that the beam accelerated from the radio frequency quadrupole （RFQ） matches well with the acceptance of the following drift tube linac （DTL） in both the transverse and longitudinal phase spaces,and that most of the particles can be captured by the final sector focusing cyclotron for further acceleration.The longitudinal emittance of the RFQ and the longitudinal acceptance of the DTL was calculated in detail,and a multi-particle beam dynamics simulation from the ion source to the end of the DTL was done to verify the original design.
基金Supported by National Natural Science Foundation of China （10635090）
文摘A new SSC-linac system （injector into separated sector cyclotron） is being designed in the HIRFL （heavy ion research facility of Lanzhou）. As part of SSC-Linac, the LEBT （low energy beam transport） consists of seven solenoids, four quadrupoles, a bending magnet and an extra multi-harmonic buncher. The total length of this segment is about 7 meters. The beam dynamics in this LEBT has been studied using three-dimensional PIC （particle-in-cell） code BEAMPATH. The simulation results show that the continuous beam from the ion source is first well analyzed by a charge-to-mass selection system, and the beam of the selected charge-to-mass ratio is then efficiently pre-bunched by a multi-harmonic buncher and optimally matched into the RFQ （radio frequency quadrupole） for further acceleration. The principles and effects of the solenoid collimation channel are discussed, and it could limit the beam emittance by changing the aperture size.
