【作者】 姚红娟；

【导师】 林郁正； 张天爵；

【作者基本信息】 清华大学 ， 核科学与技术， 2008， 博士

【摘要】 在放射性核束物理快速发展的国际环境下,中国原子能科学研究院提出了建立北京放射性核束装置的建议,需要设计一台最高能量为100MeV,平均流强200μA~500μA的质子回旋加速器作为驱动加速器。考虑到已有的技术储备、多束流可变能量的引出要求和投资费用,这台加速器采用外部加速负氢剥离引出质子的紧凑型回旋加速器方案,此将成为国际上该能级的首台紧凑型强流回旋加速器,因此在设计和研制中会存在很多的技术难点。本论文是围绕如何解决紧凑型回旋加速器的轴向注入和中心区运动问题而展开的。这些问题的成功解决,无论是技术上的还是理论上的都将会有着重要的意义。论文对该强流紧凑型回旋加速器从离子源出口至中心区整个注入和加速过程的束流动力学进行系统的研究。解决了包括主磁铁通道、低能束脉冲化等非常规部件在内的轴向注入线布局、匹配计算,并研究了中性化等问题;针对螺旋静电偏转板研究了传输矩阵、边缘场效应的问题;着重研究了中心区内离子在静态非均匀磁场、高频电场共同作用下的运动特性,在获得参考粒子加速轨道之后,进行了径向和轴向相空间的束流匹配,研究了径向振荡、轴向聚焦、横-纵耦合等非线性问题,从而确定了注入条件和磁铁极头与中心区电极的结构以获得最佳束流品质。本论文首次提出从离子源出口至紧凑型回旋加速器内部的束流发射度匹配方法,并研究了该类型加速器中心区狭小空间内多物理场耦合的束流动力学问题,完成了CYCIAE-100回旋加速器的轴向注入系统和中心区的设计。考虑到CYCIAE-100工程建设的重要性,在中国原子能科学研究院专门建造了强流回旋加速器中心区综合试验装置对上述设计研究的结果进行试验验证。装置的建造与试验过程中基于物理设计结果开发专用程序指导各类异形非标部件的多轴数控加工;制作专用工具保证螺旋偏转板与中心区的安装精度;通过多测量点监控调束、解决试验过程中的大量工程实际问题,获得了93%的注入效率,高频相位接收度达到设计要求。更多还原

【Abstract】 Under the international environment of the fast development on the RIB physics, China Institute of Atomic Energy (CIAE) proposed a BRIF project, which requires a 100MeV proton cyclotron with an average current of 200μA~500μA as a driven accelerator. The high intensity compact cyclotron with an external ion source and an axial injection system will meet a number of technologic challenges. Our dissertation is devoted to investigating problems on the injection system and the central region for the compact cyclotron; a successful solution to these problems will be of great significance both in the technology field and theory field.The thesis works on the beam dynamics study for the compact cyclotron from the external ion source to the procedure of acceleration. A series of investigations on beam transportation have been performed with focus on the layout of the axial injection line, including the main magnet passage and the pulse beam injection; the matching calculations were conducted and the neutralization of H- beam was taken into account. For the spiral inflector, the transfer matrix and fringe electric field were studied. Meanwhile we have attached importance to the beam behavior study in the central region under the joint effects of the magnetic field and electric field on the beam. After the accelerated equilibrium orbit was obtained, we calculated the beam matching in the radial and vertical phase space, and studied radial oscillation, vertical focusing and transverse-longitudinal coupling, etc. Then the injection conditions were determined and proper electrodes were designed to produce the optimum beam qualities. It is put forward in this thesis for the first time the beam matching method from the ion source to the central region of the cyclotron, and a good deal of efforts have been dedicated to the beam dynamics study under multi-physics field for the compact cyclotron, based on which the design of the axial injection system and the central region for CYCIAE-100 were accomplished.A test platform for CYCIAE-100, normally referred to as the CRM cyclotron, was built in CIAE for various experimental verifications for the 100MeV machine. Based on the results of physical design, a specific code was developed to direct the multi-axes numerical milling for various nonstandard elements; then special service tools were manufactured to guarantee the fabricating precision. In order to achieve sufficient information to optimize the beam current, we applied different beam diagnostics devices and obtiained a desirable transmission efficiency of up to 93% for the injection system. In the mean time, the result of RF phase acceptance proves to be in agreement with the physical design.更多还原