Development of an in-vacuum minipole undulator

An in-vacuum minipole insertion device is currently being developed in collaboration between and the National Synchrotron Light Source (NSLS). The magnetic array is constructed by SPring-8 and it will be installed in a chamber with mechanical parts in the X-ray ring (E=2.584 GeV) at the NSLS. The device is made of permanent magnets with 31 periods and the length of the period is 11 mm. It is to produce the fundamental radiation at 4.6 KeV which will be mainly used for X-ray photo-correlation spectroscopy (XPCS), and modest value of deflection parameter (K=0.7@3.3 mm gap) enables higher harmonics to be used for a variety of experiments. We describe technical difficulties of constructing this type of device as well as the outline of our collaboration.