Whole-beam self-focusing in fusion-relevant plasma

Journal article

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 characterisation 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 fullscale particle-in-cell simulations. We present observations of long lived, straight channels produced by the Habara-Kodama-Tanaka (HKT) wholebeam self-focusing mechanism, overcoming a critical barrier on the path to realising fast ignition.

Authors: Spiers, BT; Hill, M; Brown, C; Ceurvorst, L; Ratan, N

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Society
• Journal: Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
• Volume: 379
• Issue: 2189
• Article number: 20200159
• Publication date: 2020-12-07
• Acceptance date: 2020-09-03
• DOI: 10.1098/rsta.2020.0159
• EISSN: 1471-2962
• ISSN: 1364-503X
• Language: English
• Keywords: plasma channelling; laser-plasma interactions; proton radiography; inertial confinement fusion; fast ignition; synthetic diagnostics; FFR