UPDATE OF THE FELI PROJECT DESIGN STUDY OF IR-FEL AND UV-FEL FACILITIES FOR INDUSTRIAL USE

Two approaches for improving the beam qualities of rf-linacs and storage rings are discussed to generate an intense UV-FEL. On the basis of these discussions, a design study of IR- and UV-FEL facilities using a 170-MeV, S-band linac and a 700-MeV racetrack type storage ring has been done for industrial use. The linac beam will be sent to four undulators using four S-type BT systems installed at 35-, 80-, 130-, and 180-MeV sections at a 30-mus rf pulse operation. The ratio of the cavity length to the undulator length is designed to be less than 2.5. The beam, once used for lasing at the 35-MeV section or at the 80-MeV section, can be bent back to the following accelerating waveguide and is reaccelerated and reused for lasing. Finally, the linac beam, twice used for lasing, is used again for injection into a 700-MeV ring, like NIJI-IV, with an optical klystron, and for positron generations. FELs with three different wavelengths, covering the spectral range from 0.2 to 20 mum, can be used simultaneously, using these undulators and an optical klystron.