Bright synchrotron radiation from relativistic self-trapping of a short laser pulse in near-critical density plasma.

In a dense gas plasma a short laser pulse propagates in a relativistic self-trapping mode, which enables the effective conversion of laser energy to the accelerated electrons. This regime sustains effective loading which maximizes the total charge of the accelerating electrons, that provides a large amount of betatron radiation. The three-dimensional particle-in-cell simulations demonstrate how such a regime triggers x-ray generation with 0.