A 2.7 mm period hybrid PM undulator

Experimental results on research and development of a 2.7 mm period hybrid undulator are presented. The classical Halbach scheme was used with 1-mm-thick NdFeB plates as permanent magnets. Transformer iron plates of 0.35 mm thickness were used as soft magnetic material. Maximum field amplitude attained in the median plane is about 3 kG (K=0.08) at 1.35 mm gap and 5 kG (K=0.14) at 1 mm gap.