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Mannion OM, Crilly AJ, Forrest CJ, Appelbe BD, Betti R, Glebov VY, Gopalaswamy V, Knauer JP, Mohamed ZL, Stoeckl C, Chittenden JP, Regan SP. Measurements of the temperature and velocity of the dense fuel layer in inertial confinement fusion experiments. Phys Rev E 2022; 105:055205. [PMID: 35706215 DOI: 10.1103/physreve.105.055205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 04/05/2022] [Indexed: 06/15/2023]
Abstract
The apparent ion temperature and mean velocity of the dense deuterium tritium fuel layer of an inertial confinement fusion target near peak compression have been measured using backscatter neutron spectroscopy. The average isotropic residual kinetic energy of the dense deuterium tritium fuel is estimated using the mean velocity measurement to be ∼103 J across an ensemble of experiments. The apparent ion-temperature measurements from high-implosion velocity experiments are larger than expected from radiation-hydrodynamic simulations and are consistent with enhanced levels of shell decompression. These results suggest that high-mode instabilities may saturate the scaling of implosion performance with the implosion velocity for laser-direct-drive implosions.
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Affiliation(s)
- O M Mannion
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - A J Crilly
- Centre for Inertial Fusion Studies, The Blackett Laboratory, Imperial College, London SW72AZ, United Kingdom
| | - C J Forrest
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - B D Appelbe
- Centre for Inertial Fusion Studies, The Blackett Laboratory, Imperial College, London SW72AZ, United Kingdom
| | - R Betti
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - V Yu Glebov
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - V Gopalaswamy
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - J P Knauer
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - Z L Mohamed
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - C Stoeckl
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - J P Chittenden
- Centre for Inertial Fusion Studies, The Blackett Laboratory, Imperial College, London SW72AZ, United Kingdom
| | - S P Regan
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
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Shah RC, Hu SX, Igumenshchev IV, Baltazar J, Cao D, Forrest CJ, Goncharov VN, Gopalaswamy V, Patel D, Philippe F, Theobald W, Regan SP. Observations of anomalous x-ray emission at early stages of hot-spot formation in deuterium-tritium cryogenic implosions. Phys Rev E 2021; 103:023201. [PMID: 33736107 DOI: 10.1103/physreve.103.023201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 01/07/2021] [Indexed: 11/07/2022]
Abstract
In deuterium-tritium cryogenic implosions, hot-spot x-ray self-emission is observed to begin at a larger shell radius than is predicted by a one-dimensional radiation-hydrodynamic implosion model. Laser-imprint is shown to explain the observation for a low-adiabat implosion. For more-stable implosions the data are not described by the imprint model and suggest there are additional sources of decompression of the dense fuel.
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Affiliation(s)
- R C Shah
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - S X Hu
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - I V Igumenshchev
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - J Baltazar
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - D Cao
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - C J Forrest
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - V N Goncharov
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - V Gopalaswamy
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - D Patel
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - F Philippe
- CEA, DAM, DIF, 91297 Arpajon Cedex, France
| | - W Theobald
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - S P Regan
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
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Goncharov VN, Igumenshchev IV, Harding DR, Morse SFB, Hu SX, Radha PB, Froula DH, Regan SP, Sangster TC, Campbell EM. Novel Hot-Spot Ignition Designs for Inertial Confinement Fusion with Liquid-Deuterium-Tritium Spheres. PHYSICAL REVIEW LETTERS 2020; 125:065001. [PMID: 32845678 DOI: 10.1103/physrevlett.125.065001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
A new class of ignition designs is proposed for inertial confinement fusion experiments. These designs are based on the hot-spot ignition approach, but instead of a conventional target that is comprised of a spherical shell with a thin frozen deuterium-tritium (DT) layer, a liquid DT sphere inside a wetted-foam shell is used, and the lower-density central region and higher-density shell are created dynamically by appropriately shaping the laser pulse. These offer several advantages, including simplicity in target production (suitable for mass production for inertial fusion energy), absence of the fill tube (leading to a more-symmetric implosion), and lower sensitivity to both laser imprint and physics uncertainty in shock interaction with the ice-vapor interface. The design evolution starts by launching an ∼1-Mbar shock into a DT sphere. After bouncing from the center, the reflected shock reaches the outer surface of the sphere and the shocked material starts to expand outward. Supporting ablation pressure ultimately stops such expansion and subsequently launches a shock toward the target center, compressing the ablator and fuel, and forming a shell. The shell is then accelerated and fuel is compressed by appropriately shaping the drive laser pulse, forming a hot spot using the conventional or shock ignition approaches. This Letter demonstrates the feasibility of the new concept using hydrodynamic simulations and discusses the advantages and disadvantages of the concept compared with more-traditional inertial confinement fusion designs.
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Affiliation(s)
- V N Goncharov
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - I V Igumenshchev
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - D R Harding
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - S F B Morse
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - S X Hu
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - P B Radha
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - D H Froula
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - S P Regan
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - T C Sangster
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - E M Campbell
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
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