Performance improvements of the 3.3 MeV LIA

The 3.3 MeV accelerator of Southwest Institute of Fluid Physics is a linear induction accelerator (LIA), whose electron beam parameters are 2 kA, 3.3 MeV and 90 ns, built in 1991. This accelerator was designed to drive the SG-I free electron laser. The authors point out the modification to the pulsed power system of the linac and beam conditioning section of the SG-I in order to satisfy the needs for the FEL experiments. The beam current entering the wiggler has been increased. Beam quality and system reliability and stability are also improved. Beam parameters have been given at different position. The two important parameters for FEL, beam emittance and energy spread, are 0.43·rad and 1% respectively. The beam current through the space and energy spread selector into the interaction region is about 950 A. The ASE FEL output is about 100 kW. The amplified FEL output of above 10 MW power and gain of 20 db/m have been obtained