Generation of MeV x-rays with 3-mJ, picosecond laser pulses

We demonstrate High-Energy X-ray (HEX-ray) generation using 2.8-mJ, 850fs pulses on a liquid metal target in a Laser Plasma X-ray Source (LPXS). The measured HEX-ray spectra reach into the MeV spectral range. The spectra follow Boltzmann energy distributions with a maximum HEX-ray “temperature” of 420 keV. The low laser intensity requirement, orders of magnitude less than previously reported, enables operation with widely available picosecond, millijoule laser systems with hundreds of Watt average laser power. Based on lasers with Yb-doped active media, HEX-ray sources driven with kilowatt average laser power are achievable in the very near future.