BEAM QUALITY MEASUREMENT OF 100-MeV TEST LINAC

The 100-MeV Test Linac was constructed for the high brightness applications such as free electron lasers and coherent radiation generation experiments at PAL. The linac consists of a thermionic RF-gun, an alpha magnet, two accelerating structures, and a beam analysing magnet. The RF-gun is a one-cell cavity with a tungsten dispenser cathode of 3-mm diameter, and the longitudinal matching from the RF-gun to the first accelerating column is done by the alpha magnet. The RF frequency is 2856 MHz, and a SLAC 5045 klystron feeds RF power to two accelerating columns and the RFgun. In the initial beam test the achieved beam energy and current were 75 MeV and 50 mA, respectively. The longitudinal acceptance measurement with the alpha magnet is done to minimize energy spread, and the bunch length was measured with a streak camera by using OTR (Optical Transition Radiation). In this paper, the beam quality measurement results are described in detail together with the detailed description of the machine.