双平面多圈注入模拟优化程序TPIS的初步开发与验证

为满足短时间内达到高累积流强要求，HIAF/BRing采用了一种新的注入方法--双平面相空间多圈注入。该注入方法与传统单平面多圈注入方法不同，而且在国际上是首次在实际项目中采用，尚无实际运行经验。因此，对注入过程进行程序模拟研究是验证双平面多圈注入方案可行性的必要手段。为详细模拟研究BRing双平面多圈注入过程，并克服已有程序跟踪速度较慢且注入参数修改不便的缺点，本文根据双平面多圈注入的特点，建立了双平面多圈注入模型，编写了双平面多圈注入模拟优化程序TPIS（Two-Planemultiturn Injection Simulation）。通过与ORBIT程序模拟结果对比，验证了TPIS程序模拟双平面多圈注入过程的正确性。在此基础上，在TPIS程序中加入了粒子群优化算法，并对BRing注入参数进行了优化。结果表明，TPIS程序可以对注入参数进行有效优化，经过优化后，束流损失减少了28%，最终剩余累积粒子数满足BRing的流强设计指标要求，进一步验证了双平面多圈注入设计的可行性。

Development and Validation of TPIS Program for Two-plane Multiturn Injection and Optimization

In order to meet the high requirement of beam intensity in a short time, a new injection method named two-plane multiturn injection is proposed for HIAF/BRing. This method is different from the traditional single-plane multiturn injection, and it has no practical operation experience. This will be the first time to be used in a practical project. Therefore, it is necessary to verify the feasibility of the two-plane multiturn injection scheme through program simulation. In order to simulate and study the injection process in detail, and to overcome the disadvantages of existing programs such as slow tracking speed and inconvenient modification of injection parameters, the injection model and TPIS (Two-Plane multiturn Injection Simulation) program are developed. By comparing with the simulation results of ORBIT program, it proves that the TPIS program is correct to simulate the two-plane multiturn injection process. On this basis, particle swarm optimization algorithm is added into the TPIS program, and the injection parameters are optimized. The results show that the TIPS program can be used for injection parameter optimization. After the optimization, the injection beam loss is reduced by 28%, and the final accumulate particle number can meet the requirement of design beam intensity. It also verifies the feasibility of two-plane multiturn injection.