Upgrade alternatives for the nsls superconducting wiggler

The superconducting wiggler (SCW) with 4.2 Tesla field in 5 main poles has been in operation on the NSLS X-ray storage ring for more than 20 years. The inefficient cryogenic system of this wiggler uses a closed-cycle refrigerator requiring constant maintenance. It is possible to replace this insertion device with a 13-pole SCW originally built by Oxford Instruments. The cryostat of this device could be upgraded to reduce the liquid He consumption using cryocoolers, thereby greatly reducing the refrigerator operating expense. A second option is a new design of a SCW featuring internal chicaning.to serve three user beamlines simultaneously All these upgrade possibilities will be described in the paper.