强流重离子加速器装置的增强器慢引出系统

中国科学院近代物理研究所承担的强流重离子加速器装置目前已进入了初步设计阶段。增强器作为该装置的主加速器，可利用双向涂抹技术将238U35+束的粒子数累积至1.0×1011，并将其从注入能量为17 MeV/u加速至高能量，引出能量的范围为200-835 MeV/u。为了提供s量级的准连续束以开展辐照实验，增强器中设计了慢引出系统，该系统将采用三分之一共振与RF-knockout的引出方法。同步加速器中有两种不同种类的六极磁铁，用于实现色品校正与共振驱动，并在设计中考虑了两者能同时运行并互不影响。针对增强器中不同引出能量的238U35+束，对其相应的稳定接受度模拟结果进行了比较，并给出了在引出静电偏转板处的光学匹配参数，这将为增强器中重离子束的慢引出及放射性次级束流分离器的入口光学设计提供重要的理论依据。

Slow extraction system for booster ring at HIAF

The HIAF (High Intensity heavy ion Accelerator Facility) project, proposed by the Institute of Modern Physics (IMP) of Chinese Academy of Sciences, has entered the preliminary design stage. As the key accelerator of the HIAF complex, the Booster Ring (BRing) can accumulate 238U35+ beam up to 1.0×1011 particles per pulse using two plane painting injection scheme, and accelerate it from injection energy of 17 MeV/u to high extraction energy range of 200-835 MeV/u. To provide quasi-continuous beam in several seconds for irradiation and some special nuclear physics experiments, slow extraction system has been designed. The third order resonance and RF-knockout extraction scheme will be adopted for the slow extraction system. Two kinds of sextupoles in the synchrotron, for correcting chromaticity and driving resonance, are considered to be orthogonal. This paper discusses the simulation results for the large and the small stable acceptance in the BRing and presents the optical parameters at the electrostatic septum ESe1 for different extraction energies of the 238U35+ beam. It can provide important theoretical base for slowly extracted heavy ion beams from the BRing, and for the entrance lattice design of HIAF FRagment Separator (HFRS).