高能同步辐射光源低能束流输运线设计研究

高能同步辐射光源（HEPS）是计划在北京建造的发射度小于60 pm?rad的超低发射度光源。它由1台500 MeV直线加速器、1条500 MeV低能束流输运线、1台500 MeV～6 GeV的能量增强器、2条6 GeV的高能束流输运线、1台6 GeV的储存环以及同步辐射光束线和实验站组成。本文进行低能束流输运线的设计研究。低能束流输运线是连接直线加速器和增强器的束流传输线，在考虑建设布局限制的基础上，对两端的束流包络进行匹配，并将直线加速器产生的束流高效传输到增强器注入点。HEPS低能束流输运线设计时采用了功能分区的设计策略，设计有3个功能区，分别是消色散注入匹配区、光学参数匹配区、输出匹配区。为校正误差对束流的影响，HEPS低能束流输运线设置了8个BPM，水平和垂直各6块校正磁铁用于束流轨道校正，校正后的轨道满足束流传输要求。

Design Study of High Energy Photon Source Low Energy Beam Transport Line

The High Energy Photon Source (HEPS), a kilometer-scale storage ring based light source, with emittance of less than 60 pm?rad, will be constructed in Beijing. The light source consists of a 500 MeV linac, a 500 MeV low energy transport line, a 500 MeV to 6 GeV booster synchrotron, two 6 GeV transport lines, a 6 GeV ultra-low emittance storage ring and beam lines and experimental stations. The low energy beam transport line which is a beam transport line connecting the linac and the booster was designed. Based on the construction layout restrictions, the beam envelopes of the linac and the booster should be matched, and the beam generated by the linac is efficiently transmitted to the booster injection point. HEPS low energy beam transport line has three functional sections, which are the achromat injection matching section, the optics matching section and the output matching section. In order to correct the error effects on the beam, 8 BPMs were set up in the HEPS low energy beam transport line. There are 6 horizontal correctors and 6 vertical correctors for beam trajectory correction.