基于单腔多束型加速器的超高强流重离子加速器的前沿研究

The purpose of this proposal is to design and devople a multi-beam type Drift Tube Linac (DTL) for very high intensity heavy ion beam injectors, using existing ion source and accelerator technologies. In this research, we want to design and manufacture a Proof-of-Pricinple machine of DTL with two beam acceleration channels, and also design a multi-beam cavity linac based injector, incluing a 4-beam type RFQ, 2-beam type DTL and harmonic model superconducting type linac, for high intensity heavy ion beam. A PoP of the 4-beam type RFQ had been published in the HIF2014, 2-beam type DTL is a new original creative design with leading researches and feasibilities. The method for accelerating high intense heavy ion beam is that using multi-beam type linac to accelerate several beams in parallel in one cavity and combining the accelerated beams finally. The PoP of the 2-beam type RFQ and 4-beam type RFQ have been studied, but the multi-beam type DTL has not been proposed ever. This proposal is a real challenge in the world and is key technology must to be developed.

目前的强流加速器都是解决强流离子源，而本申请是基于现有的离子源和加速器技术、以突破现有加速器结构限制来实现数百毫安的超高强流重离子加速器方案。本申请以设计制造一台在一个加速腔内能同时加速两个束流的漂移管型加速器（DTL）的原型机为主要目的，为中高能段的超高强流脉冲重离子加速器做前沿研究。本申请涉及的方案、关键技术和性能均处于世界领先水平。4束型RFQ的设计方案在去年的国际会议上已经公开发表，双束型DTL是最新提案，为申请者本人独创设计，具有前沿性和可行性。本申请的单腔多束型加速器的原理是把强流在发散很强的低能段时分为多个束流在一个型里加速，把束流加速到中高能段后合并为一个束流，从而达到实现加速数百毫安的重离子束流，这是世界前所未有的提案和挑战。多束型DTL的研发还从没有被提出过和挑战过，这是强流加速器的核心技术和亟需验证的方案，符合单腔多束型RFQ的原理验证机研制成功后的科学发展规律。

项目组围绕单腔多束型加速器原理样机--双束型漂移管直线加速器（DB-DTL）进行了系统的研究，到目前为止，项目组按既定计划已经全部完成了DB-DTL的关键设计：81.25MHz、2.5MeV 的腔体动力学设计、腔体的电磁结构设计和多物理场分析，并进行了DB-DTL腔体的机械设计和加工安装、腔体低功率性能测试，以及2.5MeV 质子束流实验平台搭建、腔体的高功率老炼、腔体束流调试。DB-DTL高功率实验平台的偏转磁铁及降能片的实验结果表明，DB-DTL 腔体能有效的把 RFQ 出口的560keV 的质子加速到2.5MeV，达到了设计指标和项目要求指标。