CLS真空内插入件真空系统设计

Vacuum System Design for CLS In-vacuum Insert Devices

上海同步辐射光源(SSRF)将为加拿大光源(CLS)研制2台真空内插入件,包括1台周期长度为20mm的真空内波荡器(IVU20)和1台周期长度为80mm的真空内扭摆器(IVW80)。其中,真空内扭摆器的最小工作气隙为5.2mm,该气隙下磁力达到86kN。为保证扭摆器内大梁在巨大磁力下的平面度和波纹管吊杆的安全,在内大梁的两侧安装了磁力平衡弹簧结构,ANSYS模拟结果表明内大梁的变形在允许范围内。为实现束流在通过插入件内部时轨道的准确,在真空内插入件内大梁上安装长线圈来产生磁场进行束流轨道的矫正。通过复合离子泵和非蒸散型吸气剂组合使用,2台插入件的真空度均好于5×10^(-7) Pa。

Two in-vacuum insert devices （IDs） were developed by Shanghai Synchrotron Radiation Facility （SSRF） for Canada Light Source （CLS）, including one in-vacuum undulator with 20 mm period length （IVU20） and one in-vacuum wiggler with 80 mm period length （IVW80）. For the wiggler, the magnetic force will be 86 kN when magnet gap is 5.2 mm. To ensure inner-girders flatness and bellow rods security under the great force, compensational spring structure was assembled on inner-girders. ANSYS simula- ting results show that the deformation of inner girder is in permissible range. Long coils were installed in two IDs to rectify beam orbit. With combinational ion pumps and non- evaporable getters （NEG）, vacuum degrees of two IDs are better than 5 × 10 ^-7 Pa.