Status of the BNL IFEL accelerator

A 40 MeV electron beam, using the inverse free-electron laser interaction, has been accelerated by ΔE/E=2.5% over a distance of 0.47 m. The electrons interact with a 1 - 2 GW CO2 laser beam bounded by a 2.8 mm ID sapphire circular waveguide in the presence of a tapered wiggler with Bmax∼1T and a period 2.89cm<λw<3.14cm. The experimental results of ΔE/E as a function of electron energy E, peak magnetic field Bw and laser power Wl compare well with analytical and 1-D numerical simulations and permit scaling to higher laser power and electron energy. The present status of the IFEL accelerator and planned near term development are indicated. copyright 1997 American Institute of Physics