LASING AT 352 NM OF THE NIJI-IV STORAGE-RING FREE-ELECTRON LASER

Lasing at 352 nm of the ''NIJI-IV'' storage-ring free-electron laser ( FEL) was successfully achieved on the 28th of April, 1994. To our know ledge, this is the first FEL oscillation on a compact storage ring in the ultraviolet wavelength region. The electron-beam energy was 311 Me V, and the beam current was 10 similar to 6 mA/bunch. The fluctuation of the macro-temporal structure was smaller than that observed before in the case of oscillation in the visible wavelength region. The impro vements made on the ring since 1993 proved to be quite effective for t he shorter-wavelength FELs.