MeV-Energy X Rays from Inverse Compton Scattering with Laser-Wakefield Accelerated Electrons

We report the generation of MeV x rays using an undulator and accelerator that are both driven by the same 100-terawatt laser system. The laser pulse driving the accelerator and the scattering laser pulse are independently optimized to generate a high energy electron beam (> 200 MeV) and maximize the output x-ray brightness. The total x-ray photon number was measured to be similar to 1 x 10(7), the source size was 5 mu m, and the beam divergence angle was similar to 10 mrad. The x-ray photon energy, peaked at 1 MeV (reaching up to 4 MeV), exceeds the thresholds of fundamental nuclear processes (e.g., pair production and photodisintegration). DOI: 10.1103/PhysRevLett.110.155003