COMMISSIONING AND OPERATION OF WIGGLER SWITCHYARD SYSTEM FOR DUKE FEL AND HIGS

To enable the Duke storage ring FEL to operate in VUV with adequate gain, a major storage ring upgrade was carried out in 2012 to install two additional helical FEL wigglers with a wiggler switchyard system. Using the switchyard, a quick changeover can be made between two planar OK-4 wigglers and two helical OK-5 wigglers in the middle of the FEL straight section. This system preserves the linear polarization capabilities of the Duke FEL and High Intensity Gamma-ray Source (HIGS), while enabling VUV FEL operation with a higher gain using a longer FEL with up to four helical wigglers. The switchyard upgrade was completed in Summer 2012, followed by a rapid and successful commissioning of the Duke storage ring, FEL system, and HIGS. In this paper, we describe the development of the wiggler switchyard, its installation and commissioning, and its impact on the research program at the HIGS.