Whole-beam self-focusing in fusion-relevant plasma. (7th December 2020)

• Record Type: Journal Article
• Authors: Spiers, B. T.; Hill, M. P.; Brown, C.; Ceurvorst, L.; Ratan, N.; Savin, A. F.; Allan, P.; Floyd, E.; Fyrth, J.; Hobbs, L.; James, S.; Luis, J.; Ramsay, M.; Sircombe, N.; Skidmore, J.; Aboushelbaya, R.; Mayr, M. W.; Paddock, R.; Wang, R. H. W.; Norreys, P. A.
• Is Part Of: Philosophical transactions. Volume 379:Number 2189(2021)
• Publication Date: 2020-12-07
• Subjects: inertial confinement fusion -- fast ignition -- laser–plasma interactions -- plasma channelling -- proton radiography -- synthetic diagnostics; Physical sciences -- Periodicals; Engineering -- Periodicals; Mathematics -- Periodicals; 500
• DOI: 10.1098/rsta.2020.0159
• Languages: English
• ISSNs: 1364-503X

Abstract

Abstract : Fast ignition inertial confinement fusion requires the production of a low-density channel in plasma with density scale-lengths of several hundred microns. The channel assists in the propagation of an ultra-intense laser pulse used to generate fast electrons which form a hot spot on the side of pre-compressed fusion fuel. We present a systematic characterization of an expanding laser-produced plasma using optical interferometry, benchmarked against three-dimensional hydrodynamic simulations. Magnetic fields associated with channel formation are probed using proton radiography, and compared to magnetic field structures generated in full-scale particle-in-cell simulations. We present observations of long-lived, straight channels produced by the Habara–Kodama–Tanaka whole-beam self-focusing mechanism, overcoming a critical barrier on the path to realizing fast ignition. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.