分离扇回旋加速器的接受度及效率

Acceptance and efficiency of sector-separated cyclotron

以9.7MeV/u的238U36+,5.62MeV/u的70Zn10+为典型离子,分析并模拟了分离扇回旋加速器(SSC)的注入、加速和引出,得到了SSC在理论等时场下横向和纵向的接受度。为了研究SSC在实际情况下的接受度,在实测场的基础上采用Kr-Kb方法以及Lagrange插值方法建立了与实际比较符合的等时场,计算了该等时场下SSC横向和纵向的接受度,发现了导致SSC实际接受度和传输效率低的主要原因在于注入系统中的MSI3元件和引出系统中的MSE3元件设计存在缺陷。模拟结果显示,通过改变MSI3和MSE3的曲率或者垫铁改变元件内部的场分布可以改善SSC的实际接受度和传输效率。

The injection,acceleration and extraction of sector-separated cyclotron（SSC） are analyzed and simulated to get the transverse and longitudinal acceptance,using two typical ions 238U36＋ and 70Zn10＋ with the energy of 9.7 MeV/u and 5.62 MeV/u respectively. In order to study the actual acceptance of SSC,the isochronous magnetic field model in coincidence with the real field is established by Kr-Kb and Lagrange methods on the basis of the actual measurement. The transverse and longitudinal acceptance is calculated under the above isochronous magnetic field model,and the main reason for the low efficiency and acceptance of SSC is the defaults in the design of MSI3 in the injection system and MSE3 in the extraction system. The results show that the actual efficiency and acceptance of SSC can be improved by redesigning the curvature of MSI3 and MSE3 or adopting shims in MSI3 and MSE3 to change the distribution of their inner fields.