Demonstration of High Photon Yields and Nonlinearity in Relativistic Thomson Scattering

We present a progress report on the BNL’s experiment on Thomson scattering from 60 MeV electrons in a counter‐propagating terawatt CO2 laser beam. The measured x‐ray yield averages to one photon per electron within the laser/e‐beam overlap region. The observed changes in the spectral and polar distributions of the x‐ray beam with the increase of the laser intensity mark the onset of a strong nonlinearity. This indicates that electron’s oscillation in the laser field transforms to the figure‐eight trajectory.