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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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2
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Hu SX, Ceurvorst L, Peebles JL, Mao A, Li P, Lu Y, Shvydky A, Goncharov VN, Epstein R, Nichols KA, Goshadze RMN, Ghosh M, Hinz J, Karasiev VV, Zhang S, Shaffer NR, Mihaylov DI, Cappelletti J, Harding DR, Li CK, Campbell EM, Shah RC, Collins TJB, Regan SP, Deeney C. Laser-direct-drive fusion target design with a high-Z gradient-density pusher shell. Phys Rev E 2023; 108:035209. [PMID: 37849111 DOI: 10.1103/physreve.108.035209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/05/2023] [Indexed: 10/19/2023]
Abstract
Laser-direct-drive fusion target designs with solid deuterium-tritium (DT) fuel, a high-Z gradient-density pusher shell (GDPS), and a Au-coated foam layer have been investigated through both 1D and 2D radiation-hydrodynamic simulations. Compared with conventional low-Z ablators and DT-push-on-DT targets, these GDPS targets possess certain advantages of being instability-resistant implosions that can be high adiabat (α≥8) and low hot-spot and pusher-shell convergence (CR_{hs}≈22 and CR_{PS}≈17), and have a low implosion velocity (v_{imp}<3×10^{7}cm/s). Using symmetric drive with laser energies of 1.9 to 2.5MJ, 1D lilac simulations of these GDPS implosions can result in neutron yields corresponding to ≳50-MJ energy, even with reduced laser absorption due to the cross-beam energy transfer (CBET) effect. Two-dimensional draco simulations show that these GDPS targets can still ignite and deliver neutron yields from 4 to ∼10MJ even if CBET is present, while traditional DT-push-on-DT targets normally fail due to the CBET-induced reduction of ablation pressure. If CBET is mitigated, these GDPS targets are expected to produce neutron yields of >20MJ at a driven laser energy of ∼2MJ. The key factors behind the robust ignition and moderate energy gain of such GDPS implosions are as follows: (1) The high initial density of the high-Z pusher shell can be placed at a very high adiabat while the DT fuel is maintained at a relatively low-entropy state; therefore, such implosions can still provide enough compression ρR>1g/cm^{2} for sufficient confinement; (2) the high-Z layer significantly reduces heat-conduction loss from the hot spot since thermal conductivity scales as ∼1/Z; and (3) possible radiation trapping may offer an additional advantage for reducing energy loss from such high-Z targets.
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Affiliation(s)
- S X Hu
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - L Ceurvorst
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - J L Peebles
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - A Mao
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - P Li
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Y Lu
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - A Shvydky
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - V N Goncharov
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - R Epstein
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - K A Nichols
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - R M N Goshadze
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - M Ghosh
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - J Hinz
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - V V Karasiev
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - S Zhang
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - N R Shaffer
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - D I Mihaylov
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - J Cappelletti
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - D R Harding
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - C K Li
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - E M Campbell
- MCM Consulting, San Diego, California 97127, USA
| | - R C Shah
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - T J B Collins
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - S P Regan
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - C Deeney
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
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3
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Follett RK, Wen H, Froula DH, Turnbull D, Palastro JP. Independent-hot-spot approach to multibeam laser-plasma instabilities. Phys Rev E 2022; 105:L063201. [PMID: 35854618 DOI: 10.1103/physreve.105.l063201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
The independent-hot-spot model is used to develop an analytic formulation for multibeam laser-plasma instabilities in inhomogeneous plasmas. The model is applied to the absolute two-plasmon-decay instability and shows good agreement with simulations and experiments. The success of the model indicates the emergence of single-speckle behavior for sufficiently large speckles sizes.
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Affiliation(s)
- R K Follett
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - H Wen
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - D H Froula
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - D Turnbull
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J P Palastro
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
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4
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Kraus RG, Hemley RJ, Ali SJ, Belof JL, Benedict LX, Bernier J, Braun D, Cohen RE, Collins GW, Coppari F, Desjarlais MP, Fratanduono D, Hamel S, Krygier A, Lazicki A, Mcnaney J, Millot M, Myint PC, Newman MG, Rygg JR, Sterbentz DM, Stewart ST, Stixrude L, Swift DC, Wehrenberg C, Eggert JH. Measuring the melting curve of iron at super-Earth core conditions. Science 2022; 375:202-205. [PMID: 35025665 DOI: 10.1126/science.abm1472] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The discovery of more than 4500 extrasolar planets has created a need for modeling their interior structure and dynamics. Given the prominence of iron in planetary interiors, we require accurate and precise physical properties at extreme pressure and temperature. A first-order property of iron is its melting point, which is still debated for the conditions of Earth’s interior. We used high-energy lasers at the National Ignition Facility and in situ x-ray diffraction to determine the melting point of iron up to 1000 gigapascals, three times the pressure of Earth’s inner core. We used this melting curve to determine the length of dynamo action during core solidification to the hexagonal close-packed (hcp) structure. We find that terrestrial exoplanets with four to six times Earth’s mass have the longest dynamos, which provide important shielding against cosmic radiation.
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Affiliation(s)
- Richard G Kraus
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Russell J Hemley
- Departments of Physics, Chemistry, and Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Suzanne J Ali
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Jonathan L Belof
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Lorin X Benedict
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Joel Bernier
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Dave Braun
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - R E Cohen
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
| | - Gilbert W Collins
- Department of Mechanical Engineering, Department of Physics and Astronomy, and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627, USA
| | - Federica Coppari
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | | | | | - Sebastien Hamel
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Andy Krygier
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Amy Lazicki
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - James Mcnaney
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Marius Millot
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Philip C Myint
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Matthew G Newman
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
| | - James R Rygg
- Department of Mechanical Engineering, Department of Physics and Astronomy, and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627, USA
| | - Dane M Sterbentz
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Sarah T Stewart
- Department of Earth and Planetary Sciences, University of California Davis, Davis, CA 95616, USA
| | - Lars Stixrude
- Department of Earth, Planetary, and Space Sciences, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Damian C Swift
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Chris Wehrenberg
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Jon H Eggert
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
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5
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Yang SJ, Zhuo HB, Yin Y, Liu ZJ, Zheng CY, He XT, Xiao CZ. Growth and saturation of stimulated Raman scattering in two overlapping laser beams. Phys Rev E 2020; 102:013205. [PMID: 32795067 DOI: 10.1103/physreve.102.013205] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 06/17/2020] [Indexed: 11/07/2022]
Abstract
Two-dimensional particle-in-cell simulations are presented of the linear and nonlinear developments of stimulated Raman scattering in two overlapping laser beams. The development of the most unstable mode in the linear stage is consistent with a previous paper [C. Z. Xiao et al., Phys. Plasmas 26, 062109 (2019)PHPAEN1070-664X10.1063/1.5096850] where SL mode (two beams share a common scattered light) is dominant in the overlapping region. This mode is enhanced with plasma density and correlation of beam polarizations. When lasers are cross-polarized, it backs to the single-beam Raman backscattering with weak intensity. Trapping-induced nonlinear frequency shift leads to the saturation of SL mode by detuning the coupling and broadening the spectrum. An interesting result that SL mode becomes stronger as the incidence angle increases is contrary to the theoretical prediction and it is a consequence of less efficient saturation in the nonlinear stage.
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Affiliation(s)
- S J Yang
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - H B Zhuo
- Center for Advanced Material Diagnostic Technology, Shenzhen Technology University, Shenzhen 518118, China
| | - Y Yin
- College of Science, National University of Defense Technology, Changsha 410073, China
| | - Z J Liu
- Institute of Applied Physics and Computational Mathematics, Beijing 100084, China.,HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871, China
| | - C Y Zheng
- Institute of Applied Physics and Computational Mathematics, Beijing 100084, China.,HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871, China.,Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - X T He
- Institute of Applied Physics and Computational Mathematics, Beijing 100084, China.,HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871, China.,Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - C Z Xiao
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China.,Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
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6
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Follett RK, Shaw JG, Myatt JF, Froula DH, Palastro JP. Multibeam absolute stimulated Raman scattering and two-plasmon decay. Phys Rev E 2020; 101:043214. [PMID: 32422790 DOI: 10.1103/physreve.101.043214] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 04/08/2020] [Indexed: 11/07/2022]
Abstract
Multibeam absolute instability thresholds for stimulated Raman scattering (SRS) and two-plasmon decay (TPD) are calculated in three dimensions for conditions relevant to direct-drive inertial confinement fusion experiments on the OMEGA laser and at the National Ignition Facility (NIF). Although multibeam effects are found to be significant for both instabilities, SRS is found to have less efficient multibeam coupling than TPD. The results are consistent with the observation of a TPD-dominated regime on the OMEGA laser and a SRS-dominated regime on the NIF despite the single-beam SRS threshold being lower than the single-beam TPD threshold on both facilities. The minimum instability threshold for NIF plasma parameters occurs for SRS near quarter-critical densities with a shared electromagnetic wave propagating along the beam axis.
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Affiliation(s)
- R K Follett
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester New York 14623, USA
| | - J G Shaw
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester New York 14623, USA
| | - J F Myatt
- Department of Electrical and Computer Engineering University of Alberta, 9211 116th St. NW, Edmonton, Alberta T6G 1H9, Canada
| | - D H Froula
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester New York 14623, USA
| | - J P Palastro
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester New York 14623, USA
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7
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Hu SX, Epstein R, Theobald W, Xu H, Huang H, Goncharov VN, Regan SP, McKenty PW, Betti R, Campbell EM, Montgomery DS. Direct-drive double-shell implosion: A platform for burning-plasma physics studies. Phys Rev E 2020; 100:063204. [PMID: 31962495 DOI: 10.1103/physreve.100.063204] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Indexed: 11/07/2022]
Abstract
Double-shell ignition designs have been studied with the indirect-drive inertial confinement fusion (ICF) scheme in both simulations and experiments in which the inner-shell kinetic energy was limited to ∼10-15 kJ, even driven by megajoule-class lasers such as the National Ignition Facility. Since direct-drive ICF can couple more energy to the imploding shells, we have performed a detailed study on direct-drive double-shell (D^{3}S) implosions with state-of-the-art physics models implemented in radiation-hydrodynamic codes (lilac and draco), including nonlocal thermal transport, cross-beam energy transfer (CBET), and first-principles-based material properties. To mitigate classical unstable interfaces, we have proposed the use of a tungsten-beryllium-mixed inner shell with gradient-density layers that can be made by magnetron sputtering. In our D^{3}S designs, a 70-μm-thick beryllium outer shell is driven symmetrically by a high-adiabat (α≥10), 1.9-MJ laser pulse to a peak velocity of ∼240 km/s. Upon spherical impact, the outer shell transfers ∼30-40 kJ of kinetic energy to the inner shell filled with deuterium-tritium gas or liquid, giving neutron-yield energies of ∼6 MJ in one-dimensional simulations. Two-dimensional high-mode draco simulations indicated that such high-adiabat D^{3}S implosions are not susceptible to laser imprint, but the long-wavelength perturbations from the laser port configuration along with CBET can be detrimental to the target performance. Nevertheless, neutron yields of ∼0.3-1.0-MJ energies can still be obtained from our high-mode draco simulations. The robust α-particle bootstrap is readily reached, which could provide a viable platform for burning-plasma physics studies. Once CBET mitigation and/or more laser energy becomes available, we anticipate that break-even or moderate energy gain might be feasible with the proposed D^{3}S scheme.
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Affiliation(s)
- S X Hu
- Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623, USA
| | - R Epstein
- Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623, USA
| | - W Theobald
- Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623, USA
| | - H Xu
- General Atomics, San Diego, California 92121, USA
| | - H Huang
- General Atomics, San Diego, California 92121, USA
| | - V N Goncharov
- Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623, USA
| | - S P Regan
- Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623, USA
| | - P W McKenty
- Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623, USA
| | - R Betti
- Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623, USA
| | - E M Campbell
- Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623, USA
| | - D S Montgomery
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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8
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Follett RK, Shaw JG, Myatt JF, Palastro JP, Short RW, Froula DH. Suppressing Two-Plasmon Decay with Laser Frequency Detuning. PHYSICAL REVIEW LETTERS 2018; 120:135005. [PMID: 29694175 DOI: 10.1103/physrevlett.120.135005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/06/2018] [Indexed: 06/08/2023]
Abstract
Three-dimensional laser-plasma interaction simulations show that laser frequency detuning by an amount achievable with current laser technology can be used to suppress the two-plasmon decay (TPD) instability and the corresponding hot-electron generation. For the plasma conditions and laser configuration in a direct-drive inertial confinement fusion implosion on the OMEGA laser, the simulations show that ∼0.7% laser frequency detuning is sufficient to eliminate TPD-driven hot-electron generation in current experiments. This allows for higher ablation pressures in future implosion designs by using higher laser intensities.
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Affiliation(s)
- R K Follett
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J G Shaw
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J F Myatt
- Department of Electrical and Computer Engineering, University of Alberta, 9211 116th Street NW, Edmonton, Alberta T6G 1H9, Canada
| | - J P Palastro
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - R W Short
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - D H Froula
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
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9
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Rosenberg MJ, Solodov AA, Myatt JF, Seka W, Michel P, Hohenberger M, Short RW, Epstein R, Regan SP, Campbell EM, Chapman T, Goyon C, Ralph JE, Barrios MA, Moody JD, Bates JW. Origins and Scaling of Hot-Electron Preheat in Ignition-Scale Direct-Drive Inertial Confinement Fusion Experiments. PHYSICAL REVIEW LETTERS 2018; 120:055001. [PMID: 29481170 DOI: 10.1103/physrevlett.120.055001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/18/2017] [Indexed: 06/08/2023]
Abstract
Planar laser-plasma interaction (LPI) experiments at the National Ignition Facility (NIF) have allowed access for the first time to regimes of electron density scale length (∼500 to 700 μm), electron temperature (∼3 to 5 keV), and laser intensity (6 to 16×10^{14} W/cm^{2}) that are relevant to direct-drive inertial confinement fusion ignition. Unlike in shorter-scale-length plasmas on OMEGA, scattered-light data on the NIF show that the near-quarter-critical LPI physics is dominated by stimulated Raman scattering (SRS) rather than by two-plasmon decay (TPD). This difference in regime is explained based on absolute SRS and TPD threshold considerations. SRS sidescatter tangential to density contours and other SRS mechanisms are observed. The fraction of laser energy converted to hot electrons is ∼0.7% to 2.9%, consistent with observed levels of SRS. The intensity threshold for hot-electron production is assessed, and the use of a Si ablator slightly increases this threshold from ∼4×10^{14} to ∼6×10^{14} W/cm^{2}. These results have significant implications for mitigation of LPI hot-electron preheat in direct-drive ignition designs.
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Affiliation(s)
- M J Rosenberg
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - A A Solodov
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - J F Myatt
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - W Seka
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - P Michel
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M Hohenberger
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R W Short
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - R Epstein
- 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
| | - E M Campbell
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - T Chapman
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C Goyon
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J E Ralph
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M A Barrios
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J D Moody
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J W Bates
- U. S. Naval Research Laboratory, Washington, DC 20375, USA
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10
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Depierreux S, Neuville C, Baccou C, Tassin V, Casanova M, Masson-Laborde PE, Borisenko N, Orekhov A, Colaitis A, Debayle A, Duchateau G, Heron A, Huller S, Loiseau P, Nicolaï P, Pesme D, Riconda C, Tran G, Bahr R, Katz J, Stoeckl C, Seka W, Tikhonchuk V, Labaune C. Experimental Investigation of the Collective Raman Scattering of Multiple Laser Beams in Inhomogeneous Plasmas. PHYSICAL REVIEW LETTERS 2016; 117:235002. [PMID: 27982626 DOI: 10.1103/physrevlett.117.235002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Indexed: 06/06/2023]
Abstract
Experiments have been performed evidencing significant stimulated Raman sidescattering (SRS) at large angles from the density gradient. This was achieved in long scale-length high-temperature plasmas in which two beams couple to the same scattered electromagnetic wave further demonstrating for the first time this multiple-beam collective SRS interaction. The collective nature of the coupling and the amplification at large angles from the density gradient increase the global SRS losses and produce light scattered in novel directions out of the planes of incidence of the beams. These findings obtained in plasmas conditions relevant of inertial confinement fusion experiments similarly apply to the more complex geometry of these experiments where anomalously large levels of SRS were measured.
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Affiliation(s)
| | | | - C Baccou
- LULI, UMR 7605 CNRS, Ecole Polytechnique, 91128 Palaiseau cedex, France
| | - V Tassin
- CEA, DAM, DIF, F-91297 Arpajon, France
| | | | | | - N Borisenko
- P. N. Lebedev Physical Institute, 53 Leninskii Prospect, Moscow 119991 Russia
| | - A Orekhov
- P. N. Lebedev Physical Institute, 53 Leninskii Prospect, Moscow 119991 Russia
| | - A Colaitis
- University of Bordeaux-CNRS-CEA, CELIA, F-33405 Talence cedex, France
| | - A Debayle
- CEA, DAM, DIF, F-91297 Arpajon, France
| | - G Duchateau
- University of Bordeaux-CNRS-CEA, CELIA, F-33405 Talence cedex, France
| | - A Heron
- Centre de Physique Théorique, CNRS-Ecole Polytechnique, 91128 Palaiseau cedex, France
| | - S Huller
- Centre de Physique Théorique, CNRS-Ecole Polytechnique, 91128 Palaiseau cedex, France
| | - P Loiseau
- CEA, DAM, DIF, F-91297 Arpajon, France
| | - P Nicolaï
- University of Bordeaux-CNRS-CEA, CELIA, F-33405 Talence cedex, France
| | - D Pesme
- Centre de Physique Théorique, CNRS-Ecole Polytechnique, 91128 Palaiseau cedex, France
| | - C Riconda
- LULI, UMR 7605 CNRS, Ecole Polytechnique, 91128 Palaiseau cedex, France
| | - G Tran
- CEA, DAM, DIF, F-91297 Arpajon, France
| | - R Bahr
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - J Katz
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - C Stoeckl
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - W Seka
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - V Tikhonchuk
- University of Bordeaux-CNRS-CEA, CELIA, F-33405 Talence cedex, France
| | - C Labaune
- LULI, UMR 7605 CNRS, Ecole Polytechnique, 91128 Palaiseau cedex, France
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11
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Solodov AA, Rosenberg MJ, Myatt JF, Epstein R, Regan SP, Seka W, Shaw J, Hohenberger M, Bates JW, Moody JD, Ralph JE, Turnbull DP, Barrios MA. Hydrodynamic simulations of long-scale-length plasmas for two-plasmon-decay planar-target experiments on the NIF. ACTA ACUST UNITED AC 2016. [DOI: 10.1088/1742-6596/717/1/012053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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12
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Follett RK, Delettrez JA, Edgell DH, Goncharov VN, Henchen RJ, Katz J, Michel DT, Myatt JF, Shaw J, Solodov AA, Stoeckl C, Yaakobi B, Froula DH. Two-Plasmon Decay Mitigation in Direct-Drive Inertial-Confinement-Fusion Experiments Using Multilayer Targets. PHYSICAL REVIEW LETTERS 2016; 116:155002. [PMID: 27127973 DOI: 10.1103/physrevlett.116.155002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Indexed: 06/05/2023]
Abstract
Multilayer direct-drive inertial-confinement-fusion targets are shown to significantly reduce two-plasmon decay (TPD) driven hot-electron production while maintaining high hydrodynamic efficiency. Implosion experiments on the OMEGA laser used targets with silicon layered between an inner beryllium and outer silicon-doped plastic ablator. A factor-of-5 reduction in hot-electron generation (>50 keV) was observed in the multilayer targets relative to pure CH targets. Three-dimensional simulations of the TPD-driven hot-electron production using a laser-plasma interaction code (lpse) that includes nonlinear and kinetic effects show good agreement with the measurements. The simulations suggest that the reduction in hot-electron production observed in the multilayer targets is primarily caused by increased electron-ion collisional damping.
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Affiliation(s)
- R K Follett
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J A Delettrez
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - D H Edgell
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - V N Goncharov
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - R J Henchen
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J Katz
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - D T Michel
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J F Myatt
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J Shaw
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - A A Solodov
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - C Stoeckl
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - B Yaakobi
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - D H Froula
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
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13
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Dewald EL, Hartemann F, Michel P, Milovich J, Hohenberger M, Pak A, Landen OL, Divol L, Robey HF, Hurricane OA, Döppner T, Albert F, Bachmann B, Meezan NB, MacKinnon AJ, Callahan D, Edwards MJ. Generation and Beaming of Early Hot Electrons onto the Capsule in Laser-Driven Ignition Hohlraums. PHYSICAL REVIEW LETTERS 2016; 116:075003. [PMID: 26943541 DOI: 10.1103/physrevlett.116.075003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Indexed: 06/05/2023]
Abstract
In hohlraums for inertial confinement fusion (ICF) implosions on the National Ignition Facility, suprathermal hot electrons, generated by laser plasma instabilities early in the laser pulse ("picket") while blowing down the laser entrance hole (LEH) windows, can preheat the capsule fuel. Hard x-ray imaging of a Bi capsule surrogate and of the hohlraum emissions, in conjunction with the measurement of time-resolved bremsstrahlung spectra, allows us to uncover for the first time the directionality of these hot electrons and infer the capsule preheat. Data and Monte Carlo calculations indicate that for most experiments the hot electrons are emitted nearly isotropically from the LEH. However, we have found cases where a significant fraction of the generated electrons are emitted in a collimated beam directly towards the capsule poles, where their local energy deposition is up to 10× higher than the average preheat value and acceptable levels for ICF implosions. The observed "beaming" is consistent with a recently unveiled multibeam stimulated Raman scattering model [P. Michel et al., Phys. Rev. Lett. 115, 055003 (2015)], where laser beams in a cone drive a common plasma wave on axis. Finally, we demonstrate that we can control the amount of generated hot electrons by changing the laser pulse shape and hohlraum plasma.
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Affiliation(s)
- E L Dewald
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - F Hartemann
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - P Michel
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - J Milovich
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - M Hohenberger
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - A Pak
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - O L Landen
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - L Divol
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - H F Robey
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - O A Hurricane
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - T Döppner
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - F Albert
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - B Bachmann
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - N B Meezan
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - A J MacKinnon
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - D Callahan
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
| | - M J Edwards
- Lawrence Livermore National Laboratory (LLNL), P.O. Box 808, Livermore, California 94550, USA
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14
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Michel P, Divol L, Dewald EL, Milovich JL, Hohenberger M, Jones OS, Hopkins LB, Berger RL, Kruer WL, Moody JD. Multibeam Stimulated Raman Scattering in Inertial Confinement Fusion Conditions. PHYSICAL REVIEW LETTERS 2015; 115:055003. [PMID: 26274426 DOI: 10.1103/physrevlett.115.055003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Indexed: 06/04/2023]
Abstract
Stimulated Raman scattering from multiple laser beams arranged in a cone sharing a common daughter wave is investigated for inertial confinement fusion (ICF) conditions in a inhomogeneous plasma. It is found that the shared electron plasma wave (EPW) process, where the lasers collectively drive the same EPW, can lead to an absolute instability when the electron density reaches a matching condition dependent on the cone angle of the laser beams. This mechanism could explain recent experimental observations of hot electrons at early times in ICF experiments, at densities well below quarter critical when two plasmon decay is not expected to occur.
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Affiliation(s)
- P Michel
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - L Divol
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - E L Dewald
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - J L Milovich
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - M Hohenberger
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - O S Jones
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - L Berzak Hopkins
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - R L Berger
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - W L Kruer
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - J D Moody
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
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15
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Turnbull D, Michel P, Ralph JE, Divol L, Ross JS, Berzak Hopkins LF, Kritcher AL, Hinkel DE, Moody JD. Multibeam seeded brillouin sidescatter in inertial confinement fusion experiments. PHYSICAL REVIEW LETTERS 2015; 114:125001. [PMID: 25860748 DOI: 10.1103/physrevlett.114.125001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Indexed: 06/04/2023]
Abstract
We present the first observations of multibeam weakly seeded Brillouin sidescatter in indirect-drive inertial confinement fusion (ICF) experiments. Two seeding mechanisms have been identified and quantified: specular reflections ("glint") from opposite hemisphere beams, and Brillouin backscatter from neighboring beams with a different angle of incidence. Seeded sidescatter can dominate the overall coupling losses, so understanding this process is crucial for proper accounting of energy deposition and drive symmetry. Glint-seeded scattered light could also be used to probe hydrodynamic conditions inside ICF targets.
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Affiliation(s)
- D Turnbull
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Michel
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J E Ralph
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - L Divol
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J S Ross
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - L F Berzak Hopkins
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A L Kritcher
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D E Hinkel
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J D Moody
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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16
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Follett RK, Edgell DH, Henchen RJ, Hu SX, Katz J, Michel DT, Myatt JF, Shaw J, Froula DH. Direct observation of the two-plasmon-decay common plasma wave using ultraviolet Thomson scattering. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:031104. [PMID: 25871046 DOI: 10.1103/physreve.91.031104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Indexed: 06/04/2023]
Abstract
A 263-nm Thomson-scattering beam was used to directly probe two-plasmon-decay (TPD) excited electron plasma waves (EPWs) driven by between two and five 351-nm beams on the OMEGA Laser System. The amplitude of these waves was nearly independent of the number of drive beams at constant overlapped intensity, showing that the observed EPWs are common to the multiple beams. In an experimental configuration where the Thomson-scattering diagnostic was not wave matched to the common TPD EPWs, a broad spectrum of TPD-driven EPWs was observed, indicative of nonlinear effects associated with TPD saturation. Electron plasma waves corresponding to Langmuir decay of TPD EPWs were observed in both Thomson-scattering spectra, suggesting the Langmuir decay instability as a TPD saturation mechanism. Simulated Thomson-scattering spectra from three-dimensional numerical solutions of the extended Zakharov equations of TPD are in excellent agreement with the experimental spectra and verify the presence of the Langmuir decay instability.
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Affiliation(s)
- R K Follett
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14623, USA
| | - D H Edgell
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - R J Henchen
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - S X Hu
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J Katz
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - D T Michel
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J F Myatt
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - J Shaw
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - D H Froula
- Laboratory for Laser Energetics, University of Rochester, 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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17
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Zhang J, Myatt JF, Short RW, Maximov AV, Vu HX, DuBois DF, Russell DA. Multiple beam two-plasmon decay: linear threshold to nonlinear saturation in three dimensions. PHYSICAL REVIEW LETTERS 2014; 113:105001. [PMID: 25238364 DOI: 10.1103/physrevlett.113.105001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Indexed: 06/03/2023]
Abstract
The linear stability of multiple coherent laser beams with respect to two-plasmon-decay instability in an inhomogeneous plasma in three dimensions has been determined. Cooperation between beams leads to absolute instability of long-wavelength decays, while shorter-wavelength shared waves are shown to saturate convectively. The multibeam, in its absolutely unstable form, has the lowest threshold for most cases considered. Nonlinear calculations using a three-dimensional extended Zakharov model show that Langmuir turbulence created by the absolute instability modifies the convective saturation of the shorter-wavelength modes, which are seen to dominate at late times.
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Affiliation(s)
- J Zhang
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA and Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - J F Myatt
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA and Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - R W Short
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - A V Maximov
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA and Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - H X Vu
- Electrical and Computer Engineering Department, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0407, USA
| | - D F DuBois
- Lodestar Research Corporation, 2400 Central Avenue, P-5, Boulder, Colorado 80301, USA
| | - D A Russell
- Lodestar Research Corporation, 2400 Central Avenue, P-5, Boulder, Colorado 80301, USA
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18
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Hu SX, Collins LA, Goncharov VN, Boehly TR, Epstein R, McCrory RL, Skupsky S. First-principles opacity table of warm dense deuterium for inertial-confinement-fusion applications. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:033111. [PMID: 25314551 DOI: 10.1103/physreve.90.033111] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Indexed: 06/04/2023]
Abstract
Accurate knowledge of the optical properties of a warm dense deuterium-tritium (DT) mixture is important for reliable design of inertial confinement fusion (ICF) implosions using radiation-hydrodynamics simulations. The opacity of a warm dense DT shell essentially determines how much radiation from hot coronal plasmas can be deposited in the DT fuel of an imploding capsule. Even for the simplest species of hydrogen, the accurate calculation of their opacities remains a challenge in the warm-dense matter regime because strong-coupling and quantum effects play an important role in such plasmas. With quantum-molecular-dynamics (QMD) simulations, we have derived a first-principles opacity table (FPOT) of deuterium (and the DT mixture by mass scaling) for a wide range of densities from ρ(D)=0.5 to 673.518g/cm(3) and temperatures from T=5000K up to the Fermi temperature T(F) for each density. Compared with results from the astrophysics opacity table (AOT) currently used in our hydrocodes, the FPOT of deuterium from our QMD calculations has shown a significant increase in opacity for strongly coupled and degenerate plasma conditions by a factor of 3-100 in the ICF-relevant photon-energy range. As conditions approach those of classical plasma, the opacity from the FPOT converges to the corresponding values of the AOT. By implementing the FPOT of deuterium and the DT mixture into our hydrocodes, we have performed radiation-hydrodynamics simulations for low-adiabat cryogenic DT implosions on the OMEGA laser and for direct-drive-ignition designs for the National Ignition Facility. The simulation results using the FPOT show that the target performance (in terms of neutron yield and energy gain) could vary from ∼10% up to a factor of ∼2 depending on the adiabat of the imploding DT capsule; the lower the adiabat, the more variation is seen in the prediction of target performance when compared to the AOT modeling.
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Affiliation(s)
- S X Hu
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - L A Collins
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - V N Goncharov
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - T R Boehly
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - R Epstein
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - R L McCrory
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - S Skupsky
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
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19
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Eimerl D, Campbell EM, Krupke WF, Zweiback J, Kruer WL, Marozas J, Zuegel J, Myatt J, Kelly J, Froula D, McCrory RL. StarDriver: A Flexible Laser Driver for Inertial Confinement Fusion and High Energy Density Physics. JOURNAL OF FUSION ENERGY 2014. [DOI: 10.1007/s10894-014-9697-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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20
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Seka W, Myatt JF, Short RW, Froula DH, Katz J, Goncharov VN, Igumenshchev IV. Nonuniformly driven two-plasmon-decay instability in direct-drive implosions. PHYSICAL REVIEW LETTERS 2014; 112:145001. [PMID: 24765976 DOI: 10.1103/physrevlett.112.145001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Indexed: 06/03/2023]
Abstract
Half-harmonic emission spectra and images taken during directly driven implosions show that the two-plasmon decay (TPD) instability is driven nonuniformly over the target surface and that multibeam effects dominate this instability. The images show a spatially limited extent of the TPD instability. A prominent spectral feature is used to determine the electron temperature in the corona. Near threshold the temperatures agree with one-dimensional hydrodynamic predictions but exceed them by ∼10% above the TPD threshold. Two-dimensional hydrodynamic simulations indicate that a significant part (∼20%) of the laser intensity must be locally absorbed by the TPD instability (i.e., by collisional damping of the electron plasma waves) to maintain these temperature islands.
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Affiliation(s)
- W Seka
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - J F Myatt
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - R W Short
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - D H Froula
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - J Katz
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - V N Goncharov
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
| | - I V Igumenshchev
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299, USA
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