车载加速器中子源的梯形RFQ-IH DTL耦合加速结构研究

车载加速器中子源具备在工作现场开展无损检测的能力，是国内外的前沿研究。发展结构紧凑、高分路阻抗的驱动加速器是车载加速器中子源系统的关键。为满足对加速器的尺寸、重量、功耗与成本的要求，本项目提出了梯形RFQ-IH DTL耦合加速结构，其融合了RFQ聚束效率高与DTL加速效率高的优点，整腔的分路阻抗比单独使用RFQ结构得到极大提高。梯形RFQ-IH DTL耦合加速结构应用于车载加速器中子源面临两个挑战：梯形RFQ与IH DTL之间的射频电磁场共振耦合、车载加速器中子源的耦合腔设计与优化。本项目拟从射频模拟与铝模型腔实验两个方面展开电磁场共振耦合、耦合腔调谐方案的研究与验证。在此基础上，开展面向车载加速器中子源的耦合腔设计与优化，为车载加速器中子源提供更具竞争力的驱动加速器方案。研究成果对于加速器中子源的建设具有重要的工程意义。

The transportable accelerator neutron source (TCANS) is widely developed around the world, which offers opportunities to carry out non-destructive diagnosing of outdoor objects on site. It is key to develop the compact accelerator structure with high acceleration efficiency for the TCANS system. In order to meet the requirements for the size, weight, power consumption and cost of the accelerator, a coupled acceleration structure with ladder RFQ and IH DTL has been proposed in the project. The coupled cavity combines the advantages of RFQ's high bunching efficiency and DTL's high acceleration gradient. The shunt impedance of coupled cavity is much higher than that of RFQ. The development of TCANS based ladder RFQ-IH DTL coupling acceleration structure faces two challenges: RF electromagnetic resonance coupling between ladder RFQ and IH DTL; design and optimization of coupling cavity of TCANS. The project intends to solve this key problem based on the RF simulation and cold test of aluminum prototype. Then, the design of coupling cavity for TCANS are carried out to provide a more competitive driving accelerator scheme for TCANS. The research results have great significance to the promotion of accelerator neutron sources.