Microwigglers for Submillimeter Wavelength Free-Electron Lasers

Abstract : The MIT microwiggler prototype produced on-axis magnetic fields of nearly 5 kG. Tuning was used to reduce random and systematic wiggler errors to < or - 0.5%. Temperature measurements show that 0.5 msec, 5 kG pulses can be produced at 1 Hz at an operating temperature of 40 deg C above room temperature. We are collaborating with the Brookhaven National Laboratory to develop a lambda = 532 nm FEL using a 70-period microwiggler and a 50 MeV RF LINAC. Preliminary simulation show that oscillator operation is attainable. We have made preliminary measurements of a 20-period subsection of the MIT microwiggler. Saturation characteristics are acceptable and field uniformity without tuning is around 1% RMS. The enclosed photograph shows the partially assembled microwiggler whose completed length will consist of 70 periods. (RH)