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Palastro JP, Miller KG, Follett RK, Ramsey D, Weichman K, Arefiev AV, Froula DH. Space-Time Structured Plasma Waves. PHYSICAL REVIEW LETTERS 2024; 132:095101. [PMID: 38489653 DOI: 10.1103/physrevlett.132.095101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/25/2024] [Indexed: 03/17/2024]
Abstract
Electrostatic waves play a critical role in nearly every branch of plasma physics from fusion to advanced accelerators, to astro, solar, and ionospheric physics. The properties of planar electrostatic waves are fully determined by the plasma conditions, such as density, temperature, ionization state, or details of the distribution functions. Here we demonstrate that electrostatic wave packets structured with space-time correlations can have properties that are independent of the plasma conditions. For instance, an appropriately structured electrostatic wave packet can travel at any group velocity, even backward with respect to its phase fronts, while maintaining a localized energy density. These linear, propagation-invariant wave packets can be constructed with or without orbital angular momentum by superposing natural modes of the plasma and can be ponderomotively excited by space-time structured laser pulses like the flying focus.
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Affiliation(s)
- J P Palastro
- University of Rochester, Laboratory for Laser Energetics, Rochester, New York 14623-1299, USA
| | - K G Miller
- University of Rochester, Laboratory for Laser Energetics, Rochester, New York 14623-1299, USA
| | - R K Follett
- University of Rochester, Laboratory for Laser Energetics, Rochester, New York 14623-1299, USA
| | - D Ramsey
- University of Rochester, Laboratory for Laser Energetics, Rochester, New York 14623-1299, USA
| | - K Weichman
- University of Rochester, Laboratory for Laser Energetics, Rochester, New York 14623-1299, USA
| | - A V Arefiev
- Department of Mechanical and Aerospace Engineering, University of California at San Diego, La Jolla, California 92093, USA
| | - D H Froula
- University of Rochester, Laboratory for Laser Energetics, Rochester, New York 14623-1299, USA
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Turnbull D, Katz J, Sherlock M, Divol L, Shaffer NR, Strozzi DJ, Colaïtis A, Edgell DH, Follett RK, McMillen KR, Michel P, Milder AL, Froula DH. Inverse Bremsstrahlung Absorption. PHYSICAL REVIEW LETTERS 2023; 130:145103. [PMID: 37084458 DOI: 10.1103/physrevlett.130.145103] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/20/2023] [Indexed: 05/03/2023]
Abstract
Inverse bremsstrahlung absorption was measured based on transmission through a finite-length plasma that was thoroughly characterized using spatially resolved Thomson scattering. Expected absorption was then calculated using the diagnosed plasma conditions while varying the absorption model components. To match data, it is necessary to account for (i) the Langdon effect; (ii) laser-frequency (rather than plasma-frequency) dependence in the Coulomb logarithm, as is typical of bremsstrahlung theories but not transport theories; and (iii) a correction due to ion screening. Radiation-hydrodynamic simulations of inertial confinement fusion implosions have to date used a Coulomb logarithm from the transport literature and no screening correction. We anticipate that updating the model for collisional absorption will substantially revise our understanding of laser-target coupling for such implosions.
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Affiliation(s)
- D Turnbull
- University of Rochester Laboratory for Laser Energetics, Rochester 14623, New York, USA
| | - J Katz
- University of Rochester Laboratory for Laser Energetics, Rochester 14623, New York, USA
| | - M Sherlock
- Lawrence Livermore National Laboratory, Livermore 94550, California, USA
| | - L Divol
- Lawrence Livermore National Laboratory, Livermore 94550, California, USA
| | - N R Shaffer
- University of Rochester Laboratory for Laser Energetics, Rochester 14623, New York, USA
| | - D J Strozzi
- Lawrence Livermore National Laboratory, Livermore 94550, California, USA
| | - A Colaïtis
- Centre Lasers Intenses et Applications, Talence 33400, France
| | - D H Edgell
- University of Rochester Laboratory for Laser Energetics, Rochester 14623, New York, USA
| | - R K Follett
- University of Rochester Laboratory for Laser Energetics, Rochester 14623, New York, USA
| | - K R McMillen
- University of Rochester Laboratory for Laser Energetics, Rochester 14623, New York, USA
| | - P Michel
- Lawrence Livermore National Laboratory, Livermore 94550, California, USA
| | - A L Milder
- University of Alberta, Edmonton, Alberta T6G 2R3, Canada
| | - D H Froula
- University of Rochester Laboratory for Laser Energetics, Rochester 14623, New York, USA
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Milder AL, Zielinski J, Katz J, Rozmus W, Edgell D, Hansen A, Sherlock M, Bruulsema C, Palastro JP, Turnbull D, Froula DH. Direct Measurement of the Return Current Instability in a Laser-Produced Plasma. PHYSICAL REVIEW LETTERS 2022; 129:115002. [PMID: 36154407 DOI: 10.1103/physrevlett.129.115002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/22/2022] [Accepted: 08/11/2022] [Indexed: 06/16/2023]
Abstract
Measurements were made of the return current instability growth rate, demonstrating its concurrence with nonlocal transport. Thomson scattering was used to measure a maximum growth rate of 5.1×10^{9} Hz, which was 3 times less than classical Spitzer-Härm theory predicts. The measured plasma conditions indicate the heat flux was nonlocal, and Vlasov-Fokker-Planck simulations that account for nonlocality reproduce the measured growth rates. Furthermore, the threshold for the return current instability was measured (δ_{T}=0.017±0.002) to be in good agreement with previous theoretical models.
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Affiliation(s)
- A L Milder
- Laboratory for Laser Energetics, 250 East River Road, Rochester, New York 14623, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14623, USA
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - J Zielinski
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - J Katz
- Laboratory for Laser Energetics, 250 East River Road, Rochester, New York 14623, USA
| | - W Rozmus
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - D Edgell
- Laboratory for Laser Energetics, 250 East River Road, Rochester, New York 14623, USA
| | - A Hansen
- Laboratory for Laser Energetics, 250 East River Road, Rochester, New York 14623, USA
| | - M Sherlock
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - C Bruulsema
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - J P Palastro
- Laboratory for Laser Energetics, 250 East River Road, Rochester, New York 14623, USA
| | - D Turnbull
- Laboratory for Laser Energetics, 250 East River Road, Rochester, New York 14623, USA
| | - D H Froula
- Laboratory for Laser Energetics, 250 East River Road, Rochester, New York 14623, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14623, USA
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Turnbull D, Katz J, Hinkel DE, Michel P, Chapman T, Divol L, Kur E, MacLaren S, Milder AL, Rosen M, Shvydky A, Zimmerman GB, Froula DH. Beam Spray Thresholds in ICF-Relevant Plasmas. PHYSICAL REVIEW LETTERS 2022; 129:025001. [PMID: 35867466 DOI: 10.1103/physrevlett.129.025001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Beam spray measurements suggest thresholds that are a factor of ≈2 to 15× less than expected based on the filamentation figure of merit often quoted in the literature. In this moderate-intensity regime, the relevant mechanism is forward stimulated Brillouin scattering. Both weak ion acoustic wave damping and thermal enhancement of ion acoustic waves contribute to the low thresholds. Forward stimulated Brillouin scattering imparts a redshift to the transmitted beam. Regarding the specific possibility of beam spray occurring outside the laser entrance holes of an indirectly driven hohlraum, this shift may be the most concerning feature owing to the high sensitivity of crossed-beam energy transfer to the interacting beam wavelengths in the subsequent overlap region.
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Affiliation(s)
- David Turnbull
- University of Rochester Laboratory for Laser Energetics, 250 E River Road, Rochester, New York 14623, USA
| | - Joseph Katz
- University of Rochester Laboratory for Laser Energetics, 250 E River Road, Rochester, New York 14623, USA
| | - Denise E Hinkel
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - Pierre Michel
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - Thomas Chapman
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - Laurent Divol
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - Eugene Kur
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - Steve MacLaren
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - Avram L Milder
- University of Rochester Laboratory for Laser Energetics, 250 E River Road, Rochester, New York 14623, USA
| | - Mordecai Rosen
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - Alex Shvydky
- University of Rochester Laboratory for Laser Energetics, 250 E River Road, Rochester, New York 14623, USA
| | - George B Zimmerman
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - Dustin H Froula
- University of Rochester Laboratory for Laser Energetics, 250 E River Road, Rochester, New York 14623, USA
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Oudin A, Debayle A, Ruyer C, Bénisti D. Reduction of Cross-Beam Energy Transfer by a Speckle Pattern. PHYSICAL REVIEW LETTERS 2021; 127:265001. [PMID: 35029462 DOI: 10.1103/physrevlett.127.265001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/26/2021] [Accepted: 11/30/2021] [Indexed: 06/14/2023]
Abstract
In this Letter, we show that cross-beam energy transfer (CBET), ubiquitous in inertial confinement fusion (ICF) experiments, may be strongly modified by the speckle pattern of the beams. This is demonstrated by the means of two-dimensional particle in cell simulations, supported by a linear model. In particular, we show that, although they would be the same in a plane wave model, the exchange rates of energy may be significantly different whether there is a plasma flow, or a wavelength shift, especially when the waves are weakly damped. When the crossed laser beams have different frequencies, the energy exchange rate is substantially reduced compared with the predictions of the plane wave model, widely used in the hydrodynamic codes that model and interpret ICF experiments. Such effects can partly explain the disagreement of the CBET predictions compared with experimental results.
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Affiliation(s)
- A Oudin
- CEA, DAM, DIF, F-91297 Arpajon, France and Université Paris-Saclay, CEA, LMCE, 91680 Bruyères-le-Châtel, France
| | - A Debayle
- CEA, DAM, DIF, F-91297 Arpajon, France and Université Paris-Saclay, CEA, LMCE, 91680 Bruyères-le-Châtel, France
| | - C Ruyer
- CEA, DAM, DIF, F-91297 Arpajon, France and Université Paris-Saclay, CEA, LMCE, 91680 Bruyères-le-Châtel, France
| | - D Bénisti
- CEA, DAM, DIF, F-91297 Arpajon, France and Université Paris-Saclay, CEA, LMCE, 91680 Bruyères-le-Châtel, France
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