Production of gamma rays by pulsed laser beam Compton scattering off   GeV-electrons using a non-planar four-mirror optical cavity
  As part of the positron source R&D for future $e^+-e^-$ colliders and Compton based compact light sources, a high finesse non-planar four-mirror Fabry-Perot cavity has recently been installed at the ATF (KEK, Tsukuba, Japan). The first measurements of the gamma ray flux produced with a such cavity using a pulsed laser is presented here. We demonstrate the production of a flux of 2.7 $\pm$ 0.2 gamma rays per bunch crossing ($\sim3\times10^6$ gammas per second) during the commissioning. 
T. Akagi, S. Araki, J. Bonis, I. Chaikovska, R. Chiche, R. Cizeron, M.   Cohen, E. Cormier, P. Cornebise, N. Delerue, R. Fla...
physics.acc-ph