Gamma rays produced by inverse Compton scattering in the Super-ACO storage ring free electron laser

Abstract

The inverse Compton scattering between positron bunches and the free electron laser (FEL) of the Super-ACO storage ring generates a collimated and tunable gamma-ray beam. The use of the FEL instead of an external conventional laser, automatically provides the transverse alignment and synchronisation of the electron and optical beams. The Super-ACO FEL is operated in the 300– 430 nm range at 800 MeV with a high repetition rate (8 MHz) and an average transmitted power of 300 mW at 350 nm . High energy gamma-rays of 35 MeV are produced with a rate of 1.5×10 7 photons/ s and good monochromaticity (about 10%).