Free electron laser amplifier experiment based on 3.5 MeV linear induction accelerator

The authors´ induction linac is designed to drive the SG-1 FEL. The SG-1 facility is divided into three regions, the accelerator, the beam conditioning section and the interaction region. After the FEL experiments in 1993, in order to satisfy the needs for the FEL experiments and achieve high power FEL output, many modifications have been carried out in the beam conditioning section and RF input way, resulting in the increase of the current entered the wiggler and microwave output. In this paper the 3.5 MeV LIA and modifications to the linac have been briefly described. Then the FEL experiments and their results are also introduced. Finally discussions on the experiments have been given