DEVELOPMENT OF AN IN-VACUUM MINIPOLE UNDULATOR ARRAY FOR NATIONAL SYNCHROTRON LIGHT-SOURCE IN-VACUUM UNDULATOR

An in-vacuum minipole (short period) insertion device has been develop ed in a collaboration between SPring-8 and the National Synchrotron li ght Source (NSLS). The magnetic arrays were assembled, field measured, corrected, and vacuum tested by SPring-8 and were installed in an NSL S-developed chamber with mechanical parts in the NSLS X-Ray Ring (E = 2.584 GeV) in May 1997 and a successful commissioning of the device wa s carried out in June 1997. The device is made of permanent magnets wi th 30.5 periods and a period length of 11 mm, It is designed to produc e fundamental radiation at 4.6 keV, and with a modest value of deflect ion parameter (K = 0.7 at 3.3 mm gap) enables higher harmonics to be u sed as well, fora variety of experiments. A detailed description of th e mechanical support and vacuum chamber will be reported elsewhere. We describe technical challenges encountered in constructing this type o f device, and present an outline of our collaboration. (C) 1998 Americ an Institute of Physics.