Electron Beam Properties from a Compact Seeded Terahertz FEL Amplifier at Kyoto University

Abstract

A compact seeded Terahertz FEL amplifier is started construction at Institute of Advanced Energy, Kyoto University, Japan. The system consists of a 1.6 cell BNL type S-Band photocathode RF-gun, a magnetic bunch compressor in form of a chicane, triplet quadrupole magnets and a short planar undulator. Electron beams from the photocathode RF-gun were measured and compared with the PARMELA simulation results. Numerical and experimental studies on the contribution of the space charge effect were carried out. By using the RF power of 9 MW, the RF phase of 40 degree, the laser pulse energy of 20 μJ, and the solenoid magnet current of 135 A, the electron beam with a bunch charge of 50 pC, a beam energy of around 5 MeV and an RMS emittance of 6-8 mm-mrad was achieved.