A PROPOSED EXPERIMENT FOR BEAM CONDITIONING

An experiment on beam conditioning [1] is proposed for the Accelerator Test Facility (ATF) at Brookhaven National Laboratory. The proposed d emonstration will employ the already approved Harmonic Generation FEL [2] experiment (HGFEL) at the facility. The HGFEL experiment will use a 30 MeV electron beam from the ATF and a seed laser to produce a 3.4 mum radiation from a superconducting wiggler with a 1.8 cm period. In the proposed experiment, the beam energy is reduced to 17 MeV, and onl y the second wiggler of the HGFEL is employed. Resonance is made at 10 .6 mum. The demonstration involves spoiling the emittance to drastical ly reduce the output power. A beam conditioning section introduces mom entum variations correlated with betatron amplitude. This correlation will correct the deleterious effects of the artificially introduced em ittance increase thus providing a clear demonstration of the condition er.