Test Results of the CLIC Damping Wiggler Prototype

The Compact Linear Collider (CLIC) will require ultralow emittance electron and positron beams. Such emittance will be achieved by radiative damping in the CLIC damping rings that will be realized by a use of high-field short-period superconducting damping wigglers. In the course of the CLIC technical feasibility studies, a full-scale damping wiggler prototype was fabricated in BINP. Main parameters of the wiggler are 51 mm of period, 3 T of magnetic field, 1.8 m of magnetic length, 18 mm of the pole gap, and indirect cooling by LHe. Four cryocoolers were used in the wiggler design, which allow its ordinary operation without LHe consumption. Above the magnetic requirements, the main design challenges for this prototype are scalability, particularly of the cooling concept, modularity, and the capability of sustaining a high radiative heat load. The wiggler powering tests and performance of the cryogenic system are described in this paper.