CRYOGENIC DESIGN OF A PrFeB-BASED UNDULATOR

A PrFeB-based cryogenic undulator has been built at Helmholtz-Zentrum Berlin (HZB) in collaboration with the Ludwig-Maximilian-University Munchen (LMU). LMU will operate the undulator at a laser plasma accelerator at the Max-Planck-Institut fur Quantenoptik in Garching. The 20-period device has a period length of 9mm and a fixed gap of 2.5mm. The operation of a small gap device at a high emittance electron beam requires stable magnetic material. A high coercivity is achieved with PrFeB-material cooled down to 20-30K. In this paper we present the mechanic, magnetic and cryogenic design and compare predictions with measured data.