BEAM OPTICS SIMULATION OF RARE-RI RING AT RI BEAM FACTORY IN RIKEN
BEAM OPTICS SIMULATION OF RARE-RI RING AT RI BEAM FACTORY IN RIKEN
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RIKEN RI 光束工厂 RARE-RI 环的光束光学模拟
DOI：
10.1142/s0218301309012550
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
T. Ohtsubo
中科院分区：
文献类型：
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作者：
I. Arai;A. Ozawa;Y. Yasuda;T. Fujinawa;N. Fukunishi;T. Ohnishi;A. Goto;K. Hara;H. Sakurai;M. Wakasugi;Y. Yamaguchi;Y. Yano;Takeshi Suzuki;Takayuki Yamaguchi;T. Kikuchi;T. Ohtsubo
用于Rare-RI Ring项目的回旋加速器式储存环由6个磁扇区和6个直段组成，周长为56.13米。磁区对弯曲和聚焦都起作用。假设总循环为1，000转。当束流发射度为几十π mm·mrad时，在动量为-1%~+1%（μ p/p）范围内，所需的等时性为10 ~（-6）。为了验证回旋加速器储存环的设计和确定其参数，我们开发了一个高精度的束流光学模拟。为了在可行的计算时间内实现尽可能高的精度，我们采用了几何跟踪假设一个小的空间段的圆形轨道。为此目的，在计算中将磁扇区划分为150个子扇区就足够了。在每个子扇区中，磁场作为径向位置的函数给出，但在束轨迹附近是均匀的。采用四阶龙格-库塔法计算了束流轨迹。最后，我们已经实现了10-9的精度在1,000转/T和1.8秒的计算时间在一个典型的PC服务器上的单粒子经历一个循环的光线追踪。
The cyclotron-like storage ring dedicated to Rare-RI Ring project consists of 6 magnetic sectors and 6 straight sections, having a circumference of 56.13 m. The magnetic sector works for both bending and focusing. The total circulation is assumed to be 1,000 turns. Over the momentum range from -1% to +1% in ∆p/p, the required isochronisity is 10-6 while the beam emittance is sevaral tens of π mm-mrad. To examine the design of cyclotron-like storage ring and fix its parameters, we have developed a high precision beam optics simulation. To achieve the precision as high as possible within a feasible computational time, we have adopted a geometrical tracking assuming a circular orbit for a small spatial segment. For that purpose, it is enough that the magnetic sector is divided into 150 sub-sectors in calculation. In each sub-sector, the magnetic field is given as a function of radial position but uniform around the vicinity of beam trajectory. The beam trajectory is evaluated in 4th order Runge-Kutta algorithm. Finally, we have achieved a precision of 10-9 in ∆T/T and a computational time of 1.8 sec on a typical PC server for ray tracing of single particle undergoing a circulation of 1,000 turns.