S波段10 MeV辐照用行波电子加速器研究

清华大学加速器实验室研制了10 MeV行波直线加速器,并成功应用在了辐照加工领域。在对该加速管的束流崩溃现象进行了理论和实验研究后,确定了提高阈值电流、优化结构的方案,完成了腔间相移变化的新型聚束段结构。该结构能够有效降低聚束段受困高阶模对电子的横向作用,同时不影响主模的加速性能,可以提高该行波加速管的束流崩溃阈值电流。依照该方案进行了加速管的加工、成管焊接、冷测及高功率实验,冷测及高功率实验结果与模拟设计符合得很好,阈值电流提高了约40 mA,证明了该设计的可行性。该工作为行波加速器解决束流不稳定性问题,进一步提高靶流功率提供了新的方法。

Study of an S-Band Travelling-Wave Electron Linacfor Irradiation

A 10 MeV travelling-wave linac has been developed by Tsinghua University and then applied in irradiation processing successfully.After theoretical and experimental study on the beam breakup(BBU)phenomenon,the bunching section was redesigned to increase the output threshold current.By adjusting the geometrical parameters of bunching section,a novel bunching structure with varying phase shift among cavities was completed.This design could improve the threshold current of the travelling-wave linac without affecting the domain mode,due to the less transverse effect on electrons.After mechanical design,processing and brazing of the new disk-load structures,cold and high-power tests of the accelerator were carried out.The test results were in good agreement with the simulation,and the threshold current increased by about 40 mA,which proved the feasibility of the design.This work provides a new method to solve the beam instability and further increase the output powerof the traveling-wave linac.