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

• Published in: arXiv.org
• Main Authors: Lobok, M G, Andriyash, I A, Vais, O E, Malka, V, V Yu Bychenkov
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 01.05.2021
• Subjects: Electrons; Energy conversion efficiency; Gas plasmas; Lasers; Particle in cell technique; Photons; Physics - Plasma Physics; Relativistic effects; Synchrotron radiation; Synchrotrons; Trapping
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2105.00207

In a dense gas plasma a short laser pulse propagates in relativistic self-trapping mode, which enables 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 3D particle-in-cell simulations demonstrate how such regime triggers X-ray generation with 0.1-1 MeV photon energies, low divergence, and high brightness. It is shown that a 135 TW laser can be used to produce \(3\times 10^{10}\) photons of \(>10\) keV energy and a 1.2 PW laser makes it possible generating about \(10^{12}\) photons in the same energy range. The laser-to-gammas energy conversion efficiency is up to \(10^{-4}\) for the high-energy photons, \(\sim 100\) keV, while the conversion efficiency to the entire keV-range x-rays is estimated to be a few tenths of a percent.