Background Sawtooth wave buncher is widely used in low-energy ion injection at cyclotron accelerators.Its performance significantly impacts on the intensity of ion beam delivered to experimental terminals.In order to meet the high-intensity requirement of physical experiments,we upgrade the existing B02 buncher in the axial injection line of the SFC with the dual-model sawtooth wave buncher for low-energy ion injection.Methods We use a three harmonics synthesis method in the dual-sawtooth wave buncher.First,we use three harmonics to generate a low-level sawtooth wave.Second,the low-level wave is amplified by a broadband amplifier to generate high voltage at a single-gap electrode.Third,the electrode is matched to the amplifier by a 1:9 transmission line transformer.Results The new buncher has been installed online since September 2022.Our tested results show that the buncher is capable of being operated at the full-frequency mode and half-frequency mode with the corresponding frequency ranging from 2.75 to 8.0 MHz and 5.5 to 16.0 MHz,respectively.The effective voltage can be up to 2.54 kV and 1.6 kV,respectively.Also,the sawtooth wave buncher works reliably,and a 4.5-8.6 times gain in the beam intensity is achieved.Conclusion By using the three-harmonic synthesis method,a new dual-mode high-voltage sawtooth wave buncher has been built.This sawtooth wave buncher has succeeded in being applied with the high buncher voltage over a wide frequency range with good reliability and stability.This newly-built sawtooth wave buncher significantly increases the ion beam current for low-energy ion injection at the HIRFL-SFC cyclotron.
Ruifeng ZhangZhe XuXianwu WangYan CongShilong LiXiaodong HanXueming Su
为兰州重离子加速器冷却储存环(Cooler Storage Ring of Heavy Ion Research Facility in Lanzhou,HIRFLCSR)的外靶实验设计了一个γ球阵列探测器子触发判选系统,该系统根据γ球阵列探测器结构和探测到的信号特征在短时间内进行有效击中物理事例的提取。考虑到γ球阵列探测器读出通道较多,随之而来的各个通道物理事例信息之和量级较大且需要可靠、高速、长距离的数据传输结构,γ球阵列探测器触发判选系统采用主从式结构和基于光纤通信技术进行设计,同时为缓解γ球阵列探测器子触发判选系统逻辑算法的复杂性,将子触发系统划分上下行子触发系统。基于整体现场可编程门阵列(Field Programmable Gate Array,FPGA)逻辑在线重构,触发判选逻辑分层组织,实现γ球阵列探测器子触发判选系统功能的灵活重构性。结果表明,通过信号源验证能够产生正确的子触发脉冲信号,对触发判选系统间光线通信链路误码率测试达到2×10^(-14)以下,该γ球阵列探测器子触发判选系统工作良好。
