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Scott RHH, Glize K, Antonelli L, Khan M, Theobald W, Wei M, Betti R, Stoeckl C, Seaton AG, Arber TD, Barlow D, Goffrey T, Bennett K, Garbett W, Atzeni S, Casner A, Batani D, Li C, Woolsey N. Shock Ignition Laser-Plasma Interactions in Ignition-Scale Plasmas. Phys Rev Lett 2021; 127:065001. [PMID: 34420313 DOI: 10.1103/physrevlett.127.065001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/23/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
We use a subignition scale laser, the 30 kJ Omega, and a novel shallow-cone target to study laser-plasma interactions at the ablation-plasma density scale lengths and laser intensities anticipated for direct drive shock-ignition implosions at National Ignition Facility scale. Our results show that, under these conditions, the dominant instability is convective stimulated Raman scatter with experimental evidence of two plasmon decay (TPD) only when the density scale length is reduced. Particle-in-cell simulations indicate this is due to TPD being shifted to lower densities, removing the experimental back-scatter signature and reducing the hot-electron temperature. The experimental laser energy-coupling to hot electrons was found to be 1%-2.5%, with electron temperatures between 35 and 45 keV. Radiation-hydrodynamics simulations employing these hot-electron characteristics indicate that they should not preheat the fuel in MJ-scale shock ignition experiments.
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Affiliation(s)
- R H H Scott
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire OX11 OQX, United Kingdom
| | - K Glize
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire OX11 OQX, United Kingdom
| | - L Antonelli
- York Plasma Institute, Department of Physics, University of York, York YO10 5DD, United Kingdom
| | - M Khan
- York Plasma Institute, Department of Physics, University of York, York YO10 5DD, United Kingdom
| | - W Theobald
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA
| | - M Wei
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA
| | - R Betti
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA
| | - C Stoeckl
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA
| | - A G Seaton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T D Arber
- University of Warwick, Coventry CV4 7AL, United Kingdom
| | - D Barlow
- University of Warwick, Coventry CV4 7AL, United Kingdom
| | - T Goffrey
- University of Warwick, Coventry CV4 7AL, United Kingdom
| | - K Bennett
- University of Warwick, Coventry CV4 7AL, United Kingdom
| | - W Garbett
- AWE, Aldermaston, Reading, Berkshire RG7 4PR, United Kingdom
| | - S Atzeni
- Dipartimento SBAI, Università di Roma "La Sapienza", Roma 00161, Italy
| | - A Casner
- CELIA, University of Bordeaux, Bordeaux F-33405, France
| | - D Batani
- CELIA, University of Bordeaux, Bordeaux F-33405, France
| | - C Li
- MIT, Cambridge, Massachusetts 02139, USA
| | - N Woolsey
- York Plasma Institute, Department of Physics, University of York, York YO10 5DD, United Kingdom
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