Vacuum System Design for CLS In-vacuum Insert Devices

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 simulating 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.