Polychromatic x-ray beam from the acceleration of energetic electrons in ultrafast laser-produced plasmas

Polychromatic beams of hard X-rays from ultrafast laser plasma interaction are studied. Just as in a conventional synchrotron, electrons are accelerated and wiggled, but on a much shorter scale of a few millimeters. By focusing a 50 TW CPA laser system (30 fs duration) onto a helium gas jet, we obtained a polychromatic collimated beam (50 mrad) of X-ray radiation in the keV range. In addition, its perfect synchronization with the laser system, its ultrafast duration (∼30 fs) and its brightness (up to 10⁸ photons/shot/solid angle at 0.1% BW) will make it applicable to both X-ray science and backlighting to address laboratory astrophysics research issues.