Observation of 20 eV x‐ray generation in a proof‐of‐principle laser synchrotron source experiment

A laser synchrotron source (LSS) [P. Sprangle, A. Ting, E. Esarey, and A. Fisher, J. Appl. Phys. 72, 5032 (1992)] was proposed to generate short‐pulsed, tunable x rays by Thomson scattering of laser photons from a relativistic electron beam. A proof‐of‐principal (p.o.p.) experiment on this LSS configuration is performed. An intense laser pulse (λ0=1.053 μm) is Thomson backscattered from a focused relativistic electron beam. Time integrated x‐ray signals from a photocathode/electron multiplier, at an electron beam energy of 650 keV and an x‐ray photon energy of 20 eV, indicate an increase in the x‐ray signals above the baseline by an amount comparable to the theoretically predicted value.