Ultrabroad-band x-ray source using a picosecond, laser-driven plasma accelerator

An ultrabroad-band x-ray source, with photon energies from 10 keV to <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mo>></a:mo><a:mn>1</a:mn></a:math> MeV, based on a picosecond laser-driven plasma accelerator, is characterized and used to radiograph high-energy-density-science relevant targets. The measured yield of <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:msup><b:mn>10</b:mn><b:mn>12</b:mn></b:msup></b:math> photons/shot is reaching the necessary photon yields to radiograph, in a single shot, high areal density objects and matter under extreme conditions. By focusing a short laser pulse (120 J, 1 ps) into a gas jet, a <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mo><</c:mo><c:mn>100</c:mn></c:math> mrad electron beam with energies up to 350 MeV and up to 70 nC of charge was produced by a combination of laser self-modulation instability and direct laser acceleration. A foil placed at the exit of the gas jet is used to convert part of the electron beam energy into x rays through inverse bremsstrahlung and/or inverse Compton scattering, generating a bright, broad-band, high-photon-energy beam. This beam is used to radiograph a gold half hohlraum with a high-density sphere inside with relevant characteristics for high-energy-density science and inertial confinement fusion. Published by the American Physical Society 2024