The short-period wiggler for CAEP FIR-FEL

A 30-period short-period wiggler has been constructed for the FIR-FEL at CAEP. We present results on the design, construction and performance of this novel hybrid wiggler structure. The primary magnetic flux is provided by magnet blocks in the same way as the well-known Halbach hybrid wiggler scheme. The additional magnetic flux is supplied by combined Π-shaped magnet blocks. The wiggler with the 16 mm period and 5.7 mm gap has generated an on-axis peak field of 0.75 T with the on-axis rms magnetic field error of better than 0.05%. The beam deviation is not more than 18 of its amplitude.