Recent developments of insertion devices at SPring-8

The construction of the 25-m long undulator of in-vacuum type was finished successfully and installed into the 30-m straight section of the SPring-8 storage ring. The period length is 32 mm and the number of periods is 780. The maximum field is obtained as 0.59 T at the minimum gap of 12 mm. Although this device is composed of five segments, it works as a one-piece undulator without any phasing system. Following this long device, the in-vacuum revolver undulator of mini-gap type will soon be completed. This device has four undulators with different period length.