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Nichols KA, Hu SX, White AJ, Goncharov VN, Mihaylov DI, Collins LA, Shaffer NR, Karasiev VV. Time-dependent density-functional-theory calculations of the nonlocal electron stopping range for inertial confinement fusion applications. Phys Rev E 2023; 108:035206. [PMID: 37849196 DOI: 10.1103/physreve.108.035206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 08/18/2023] [Indexed: 10/19/2023]
Abstract
Nonlocal electron transport is important for understanding laser-target coupling for laser-direct-drive (LDD) inertial confinement fusion (ICF) simulations. Current models for the nonlocal electron mean free path in radiation-hydrodynamic codes are based on plasma-physics models developed decades ago; improvements are needed to accurately predict the electron conduction in LDD simulations of ICF target implosions. We utilized time-dependent density functional theory (TD-DFT) to calculate the electron stopping power (SP) in the so-called conduction-zone plasmas of polystyrene in a wide range of densities and temperatures relevant to LDD. Compared with the modified Lee-More model, the TD-DFT calculations indicated a lower SP and a higher stopping range for nonlocal electrons. We fit these electron SP calculations to obtain a global analytical model for the electron stopping range as a function of plasma conditions and the nonlocal electron kinetic energy. This model was implemented in the one-dimensional radiation-hydrodynamic code lilac to perform simulations of LDD ICF implosions, which are further compared with simulations by the standard modified Lee-More model. Results from these integrated simulations are discussed in terms of the implications of this TD-DFT-based mean-free-path model to ICF simulations.
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Affiliation(s)
- K A Nichols
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14623-1299, USA
| | - S X Hu
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14623-1299, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14623-1299, USA
| | - A J White
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - V N Goncharov
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA
- Department of Mechanical Engineering, University of Rochester, Rochester, New York 14623-1299, USA
| | - D I Mihaylov
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA
| | - L A Collins
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - N R Shaffer
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA
| | - V V Karasiev
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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