SCSS Beamline Layout

Following figure shows the beam line layout of SCSS project. The high-votlage electron with CeB6 cathode generates low emittance electron beam, whose energy is modulated with 476 MHz rf-field. After drifting, a bunched beam is formed at the entrance of L-band accelerator. The bunch compressor-1 (BC-1) compresses the bunch length from 33 psec down to 4 psec, as a result the peak current reaches 250 A. C-1 through C-4 denote the C-band accelerator unit, whose accelerating gradient is about 40 MV/m, and energy gain per unit is 300 MeV maximum. After four unit, the beam energy reaches 1 GeV nominal.

The undulator consists of five section of in-vacuum type. The undulator period is 15 mm, and the maximum K-parameter is 1.3 at the minimum gap of 3.7 mm. Each undulator section length is 4.5 m long, and 22.5 m in total. which is longer than the expected staturation length of 20 m at the shortest wavelength opeation (3.6 nm).