AN IN VACUUM WIGGLER WSV50 FOR PRODUCING HARD X-RAYS AT SOLEIL

摘要

SOLEIL is a medium energy storage ring (2.75 GeV) operating since 2006. The production of intense high energy photon beams requires Insertion Devices (ID) with high magnetic field and large number of periods. To cover the 20 - 50 keV range, an in vacuum wiggler has been preferred to a superconducting wiggler. This choice results from a compromise between photon flux, investment and running cost. Deep studies have been performed to find the optimum magnetic field and period producing the maximum flux in the dedicated spectral range (20-50 keV). The wiggler is composed of 38 periods of 50 mm producing 2.1 T at a 5.5 mm minimum gap. To minimize the high magnetic forces acting between the magnet arrays (10 tons), a compensation system has been designed. It consists of two series of 40 amagnetic springs reducing the forces down to 1 ton over the whole range of the magnetic gap variation. This paper presents the spectral performances of the wiggler compared with an optimized superconducting wiggler, the mechanical and magnetic design of the wiggler and the first tests of the compensation system.