RF structure design of the China Material Irradiation Facility RFQ
RF structure design of the China Material Irradiation Facility RFQ
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DOI：
10.1016/j.nima.2017.06.045
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发表时间：
2017-10
影响因子：
1.4
通讯作者：
Chenxing Li;Yuan He;Xianbo Xu;Zhouli Zhang;Feng-Feng Wang-Feng;W. Dou;Zhi-jun Wang;Tieshan Wang
中科院分区：
文献类型：
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作者：
Chenxing Li;Yuan He;Xianbo Xu;Zhouli Zhang;Feng-Feng Wang-Feng;W. Dou;Zhi-jun Wang;Tieshan Wang
中国材料辐照装置（CMIF）是用于聚变堆材料鉴定的加速器基中子辐照装置，其前端射频四极杆射频结构设计已经完成。该加速器的工作频率为162.5 MHz，叶片间电压为65 kV，叶片长度为5250 mm，可将10 mA连续氘束流从20 keV/u加速到1.5 MeV/u。借鉴中国加速器驱动系统（CIADS）引射器II的设计经验，选择了四叶片型腔，并进行了腔体结构设计。为了减小由于制造和装配误差引起的场的方位不对称性，利用沿纵向沿着等间距分布的20对π模稳定环（PISL），使工作模与其最近的偶极模之间的频率间隔达到17.66 MHz。在调谐方面，引入了100个段塞调谐器来补偿加工和装配引起的误差。为了获得沿着腔的均匀电场分布，引入了叶片缩减并修改了输出端板。利用多物理场方法研究了具有射频电源和水冷的谐振腔，得到了水温调谐系数。通过与世界范围内的连续波射频谐振器的比较，表明所设计的结构在连续波（CW）工作模式下的功率密度适中。
The radio frequency structure design of the radio frequency quadrupole (RFQ) for the front end of China Material Irradiation Facility (CMIF), which is an accelerator based neutron irradiation facility for fusion reactor material qualification, has been completed. The RFQ is specified to accelerate 10 mA continuous deuteron beams from the energies of 20 keV/u to 1.5 MeV/u within the vane length of 5250 mm. The working frequency of the RFQ is selected to 162.5 MHz and the inter-vane voltage is set to 65 kV. Four-vane cavity type is selected and the cavity structure is designed drawing on the experience of China Initiative Accelerator Driven System (CIADS) Injector II RFQ. In order to reduce the azimuthal asymmetry of the field caused from errors in fabrication and assembly, a frequency separation between the working mode and its nearest dipole mode is reached to 17.66 MHz by utilizing 20 pairs of π-mode stabilizing loops (PISLs) distributed along the longitudinal direction with equal intervals. For the purpose of tuning, 100 slug tuners were introduced to compensate the errors caused by machining and assembly. In order to obtain a homogeneous electrical field distribution along cavity, vane cutbacks are introduced and output endplate is modified. Multi-physics study of the cavity with radio frequency power and water cooling is performed to obtain the water temperature tuning coefficients. Through comparing to the worldwide CW RFQs, it is indicated that the power density of the designed structure is moderate for operation under continuous wave (CW) mode.