1
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Huang Y, Liang Z, Zeng J, Yuan J. Nonideal effects on ionization potential depression and ionization balance in dense Al and Au plasmas. Phys Rev E 2024; 109:045210. [PMID: 38755935 DOI: 10.1103/physreve.109.045210] [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: 11/15/2023] [Accepted: 04/04/2024] [Indexed: 05/18/2024]
Abstract
For low-density plasmas, the ionization balance can be properly described by the normal Saha equation in the chemical picture. For dense plasmas, however, nonideal effects due to the interactions between the electrons and ions and among the electrons themselves affect the ionization potential depression and the ionization balance. With the increasing of plasma density, the pressure ionization starts to play a more obvious role and competes with the thermal ionization. Based on a local-density temperature-dependent ion-sphere model, we develop a unified and self-consistent theoretical formalism to simultaneously investigate the ionization potential depression, the ionization balance, and the charge states distributions of the dense plasmas. In this work, we choose Al and Au plasmas as examples as Al is a prototype light element and Au is an important heavy element in many research fields such as in the inertial confinement fusion. The nonideal effect of the free electrons in the plasmas is considered by the single-electron effective potential contributed by both the bound electrons of different charge states and the free electrons in the plasmas. For the Al plasmas, we can reconcile the results of two experiments on measuring the ionization potential depression, in which one experiment can be better explained by the Stewart-Pyatt model while the other fits better with the Ecker-Kröll model. For dense Au plasmas, the results show that the double peak structure of the charge state distribution appears to be a common phenomenon. In particular, the calculated ionization balance shows that the two- and three-peak structures can appear simultaneously for denser Au plasmas above ∼30g/cm^{3}.
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Affiliation(s)
- Yihua Huang
- College of Science, Zhejiang University of Technology, Hangzhou Zhejiang 310023, People's Republic of China
| | - Zhenhao Liang
- College of Science, Zhejiang University of Technology, Hangzhou Zhejiang 310023, People's Republic of China
| | - Jiaolong Zeng
- College of Science, Zhejiang University of Technology, Hangzhou Zhejiang 310023, People's Republic of China
| | - Jianmin Yuan
- Institute of Atomic and Molecular Physics, Jilin University, Changchun Jilin 130012, People's Republic of China
- Graduate School of China Academy of Engineering Physics, Beijing 100193, People's Republic of China
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2
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Gawne T, Vinko SM, Wark JS. Quantifying ionization in hot dense plasmas. Phys Rev E 2024; 109:L023201. [PMID: 38491590 DOI: 10.1103/physreve.109.l023201] [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: 07/10/2023] [Accepted: 12/07/2023] [Indexed: 03/18/2024]
Abstract
Ionization is a problematic quantity in that it does not have a well-defined thermodynamic definition and yet it is a key parameter within plasma modeling. One still therefore aims to find a consistent and unambiguous definition for the ionization state. Within this context we present finite-temperature density functional theory calculations of the ionization state of carbon in CH plasmas using two potential definitions: one based on counting the number of continuum electrons, and another based on the optical conductivity. Differences of up to 10% are observed between the two methods. However, including "Pauli forbidden" transitions in the conductivity reproduces the counting definition, suggesting such transitions are important to evaluate the ionization state.
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Affiliation(s)
- Thomas Gawne
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Sam M Vinko
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - Justin S Wark
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
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3
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Gawne T, Campbell T, Forte A, Hollebon P, Perez-Callejo G, Humphries OS, Karnbach O, Kasim MF, Preston TR, Lee HJ, Miscampbell A, van den Berg QY, Nagler B, Ren S, Royle RB, Wark JS, Vinko SM. Investigating mechanisms of state localization in highly ionized dense plasmas. Phys Rev E 2023; 108:035210. [PMID: 37849197 DOI: 10.1103/physreve.108.035210] [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: 02/09/2023] [Accepted: 08/11/2023] [Indexed: 10/19/2023]
Abstract
We present experimental observations of K_{β} emission from highly charged Mg ions at solid density, driven by intense x rays from a free electron laser. The presence of K_{β} emission indicates the n=3 atomic shell is relocalized for high charge states, providing an upper constraint on the depression of the ionization potential. We explore the process of state relocalization in dense plasmas from first principles using finite-temperature density functional theory alongside a wave-function localization metric, and find excellent agreement with experimental results.
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Affiliation(s)
- Thomas Gawne
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Thomas Campbell
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Alessandro Forte
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Patrick Hollebon
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Gabriel Perez-Callejo
- Departamento de Física Teórica, Atómica y Óptica, Universidad de Valladolid, Valladolid, Spain
| | | | - Oliver Karnbach
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Muhammad F Kasim
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | | | - Hae Ja Lee
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, California 94025, USA
| | - Alan Miscampbell
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Quincy Y van den Berg
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Bob Nagler
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, California 94025, USA
| | - Shenyuan Ren
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Ryan B Royle
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Justin S Wark
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Sam M Vinko
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
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4
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Ovechkin AA, Loboda PA, Popova VV, Akulinina EY, Berezovskaya ME, Korolev AS, Kolchugin SV. Plasma ionization balance in chemical-picture and average-atom models. Phys Rev E 2023; 108:015207. [PMID: 37583194 DOI: 10.1103/physreve.108.015207] [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: 12/21/2022] [Accepted: 07/02/2023] [Indexed: 08/17/2023]
Abstract
We propose an approximate method to calculate ion partition functions in the context of the chemical-picture representation of plasmas as an interacting mixture of various ions and free electrons under the local-thermodynamic-equilibrium conditions. The method uses the superconfiguration approach and implies that the first-order corrections to the energies of excited electron configurations due to the electron-electron interaction may be replaced by a similar first-order correction to the energy of the basic configuration of an ion with the same number of bound electrons. The method enables one to significantly speed up the calculations and generally provides quite accurate results. Using the method proposed, plasma ionization balance and average ion charges calculated on the base of the chemical-picture representation show a good agreement with the relevant average-atom data. For the case of weak electron-ion nonideality, we provide approximate relations between the chemical-picture and average-atom values of the average ion charge, chemical potential, and plasma-density depression of ionization potential.
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Affiliation(s)
- A A Ovechkin
- Russian Federal Nuclear Center-Zababakhin All-Russian Research Institute of Technical Physics (RFNC-VNIITF), 13, Vasilyeva st., Snezhinsk, Chelyabinsk region 456770, Russia
| | - P A Loboda
- Russian Federal Nuclear Center-Zababakhin All-Russian Research Institute of Technical Physics (RFNC-VNIITF), 13, Vasilyeva st., Snezhinsk, Chelyabinsk region 456770, Russia
- National Research Nuclear University-Moscow Engineering Physics Institute (MEPhI), 31, Kashirskoe sh., Moscow 115409, Russia
| | - V V Popova
- Russian Federal Nuclear Center-Zababakhin All-Russian Research Institute of Technical Physics (RFNC-VNIITF), 13, Vasilyeva st., Snezhinsk, Chelyabinsk region 456770, Russia
| | - E Yu Akulinina
- Russian Federal Nuclear Center-Zababakhin All-Russian Research Institute of Technical Physics (RFNC-VNIITF), 13, Vasilyeva st., Snezhinsk, Chelyabinsk region 456770, Russia
| | - M E Berezovskaya
- Russian Federal Nuclear Center-Zababakhin All-Russian Research Institute of Technical Physics (RFNC-VNIITF), 13, Vasilyeva st., Snezhinsk, Chelyabinsk region 456770, Russia
| | - A S Korolev
- Russian Federal Nuclear Center-Zababakhin All-Russian Research Institute of Technical Physics (RFNC-VNIITF), 13, Vasilyeva st., Snezhinsk, Chelyabinsk region 456770, Russia
| | - S V Kolchugin
- Russian Federal Nuclear Center-Zababakhin All-Russian Research Institute of Technical Physics (RFNC-VNIITF), 13, Vasilyeva st., Snezhinsk, Chelyabinsk region 456770, Russia
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5
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Döppner T, Bethkenhagen M, Kraus D, Neumayer P, Chapman DA, Bachmann B, Baggott RA, Böhme MP, Divol L, Falcone RW, Fletcher LB, Landen OL, MacDonald MJ, Saunders AM, Schörner M, Sterne PA, Vorberger J, Witte BBL, Yi A, Redmer R, Glenzer SH, Gericke DO. Observing the onset of pressure-driven K-shell delocalization. Nature 2023:10.1038/s41586-023-05996-8. [PMID: 37225995 DOI: 10.1038/s41586-023-05996-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 03/22/2023] [Indexed: 05/26/2023]
Abstract
The gravitational pressure in many astrophysical objects exceeds one gigabar (one billion atmospheres)1-3, creating extreme conditions where the distance between nuclei approaches the size of the K shell. This close proximity modifies these tightly bound states and, above a certain pressure, drives them into a delocalized state4. Both processes substantially affect the equation of state and radiation transport and, therefore, the structure and evolution of these objects. Still, our understanding of this transition is far from satisfactory and experimental data are sparse. Here we report on experiments that create and diagnose matter at pressures exceeding three gigabars at the National Ignition Facility5 where 184 laser beams imploded a beryllium shell. Bright X-ray flashes enable precision radiography and X-ray Thomson scattering that reveal both the macroscopic conditions and the microscopic states. The data show clear signs of quantum-degenerate electrons in states reaching 30 times compression, and a temperature of around two million kelvins. At the most extreme conditions, we observe strongly reduced elastic scattering, which mainly originates from K-shell electrons. We attribute this reduction to the onset of delocalization of the remaining K-shell electron. With this interpretation, the ion charge inferred from the scattering data agrees well with ab initio simulations, but it is significantly higher than widely used analytical models predict6.
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Affiliation(s)
- T Döppner
- Lawrence Livermore National Laboratory, Livermore, CA, USA.
| | - M Bethkenhagen
- Institute of Physics, University of Rostock, Rostock, Germany
- École Normale Supérieure de Lyon, LGLTPE, CNRS UMR 5276, Lyon, France
| | - D Kraus
- Institute of Physics, University of Rostock, Rostock, Germany
- Department of Physics, University of California Berkeley, Berkeley, CA, USA
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - P Neumayer
- GSI Helmholtz-Zentrum für Schwerionenforschung, Darmstadt, Germany
| | | | - B Bachmann
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - R A Baggott
- The John Adams Institute for Accelerator Science, Imperial College London, London, UK
| | - M P Böhme
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Center for Advanced Systems Understanding (CASUS), Görlitz, Germany
- Technische Universität Dresden, Dresden, Germany
| | - L Divol
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - R W Falcone
- Department of Physics, University of California Berkeley, Berkeley, CA, USA
| | - L B Fletcher
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - O L Landen
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - M J MacDonald
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - A M Saunders
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - M Schörner
- Institute of Physics, University of Rostock, Rostock, Germany
| | - P A Sterne
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - J Vorberger
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - B B L Witte
- Institute of Physics, University of Rostock, Rostock, Germany
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - A Yi
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - R Redmer
- Institute of Physics, University of Rostock, Rostock, Germany
| | - S H Glenzer
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - D O Gericke
- Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry, UK
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6
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Zeng J, Li Y, Hou Y, Yuan J. Nonideal effect of free electrons on ionization equilibrium and radiative property in dense plasmas. Phys Rev E 2023; 107:L033201. [PMID: 37072979 DOI: 10.1103/physreve.107.l033201] [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: 11/28/2022] [Accepted: 02/26/2023] [Indexed: 04/20/2023]
Abstract
The thermodynamic as well as optical properties of strongly coupled plasmas depend crucially on the average degree of ionization and the ionic state composition, which, however, cannot be determined by using the normal Saha equation usually used for the ideal plasmas. Hence, an adequate treatment of the ionization balance and the charge state distribution of strongly coupled plasmas is still a challenge for theory due to the interactions between the electrons and ions and among the electrons themselves. Based on a local density temperature-dependent ion-sphere model, the Saha equation approach is extended to the regime of strongly coupled plasmas by taking into account the free-electron-ion interaction, the free-free-electron interaction, the nonuniform free-electron space distribution, and the free-electron quantum partial degeneracy. All the quantities, including the bound orbitals with ionization potential depression, free-electron distribution, and bound and free-electron partition function contributions, are calculated self-consistently in the theoretical formalism. This study shows that the ionization equilibrium is evidently modified by considering the above nonideal characteristics of the free electrons. Our theoretical formalism is validated by the explanation of a recent experimental measurement of the opacity of dense hydrocarbon.
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Affiliation(s)
- Jiaolong Zeng
- College of Science, Zhejiang University of Technology, Hangzhou Zhejiang 310023, People's Republic of China
- College of Science, National University of Defense Technology, Changsha Hunan 410073, People's Republic of China
| | - Yongjun Li
- College of Science, National University of Defense Technology, Changsha Hunan 410073, People's Republic of China
| | - Yong Hou
- College of Science, National University of Defense Technology, Changsha Hunan 410073, People's Republic of China
| | - Jianmin Yuan
- College of Science, National University of Defense Technology, Changsha Hunan 410073, People's Republic of China
- Graduate School of China Academy of Engineering Physics, Beijing 100193, People's Republic of China
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7
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Dornheim T, Böhme M, Kraus D, Döppner T, Preston TR, Moldabekov ZA, Vorberger J. Accurate temperature diagnostics for matter under extreme conditions. Nat Commun 2022; 13:7911. [PMID: 36564411 PMCID: PMC9789064 DOI: 10.1038/s41467-022-35578-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022] Open
Abstract
The experimental investigation of matter under extreme densities and temperatures, as in astrophysical objects and nuclear fusion applications, constitutes one of the most active frontiers at the interface of material science, plasma physics, and engineering. The central obstacle is given by the rigorous interpretation of the experimental results, as even the diagnosis of basic parameters like the temperature T is rendered difficult at these extreme conditions. Here, we present a simple, approximation-free method to extract the temperature of arbitrarily complex materials in thermal equilibrium from X-ray Thomson scattering experiments, without the need for any simulations or an explicit deconvolution. Our paradigm can be readily implemented at modern facilities and corresponding experiments will have a profound impact on our understanding of warm dense matter and beyond, and open up a variety of appealing possibilities in the context of thermonuclear fusion, laboratory astrophysics, and related disciplines.
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Affiliation(s)
- Tobias Dornheim
- grid.510908.5Center for Advanced Systems Understanding (CASUS), Görlitz, D-02826 Germany ,grid.40602.300000 0001 2158 0612Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, D-01328 Germany
| | - Maximilian Böhme
- grid.510908.5Center for Advanced Systems Understanding (CASUS), Görlitz, D-02826 Germany ,grid.40602.300000 0001 2158 0612Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, D-01328 Germany ,grid.4488.00000 0001 2111 7257Technische Universität Dresden, Dresden, D-01062 Germany
| | - Dominik Kraus
- grid.40602.300000 0001 2158 0612Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, D-01328 Germany ,grid.10493.3f0000000121858338Institut für Physik, Universität Rostock, Rostock, D-18059 Germany
| | - Tilo Döppner
- grid.250008.f0000 0001 2160 9702Lawrence Livermore National Laboratory, Livermore, CA 94550 USA
| | - Thomas R. Preston
- grid.434729.f0000 0004 0590 2900European XFEL, Schenefeld, D-22869 Germany
| | - Zhandos A. Moldabekov
- grid.510908.5Center for Advanced Systems Understanding (CASUS), Görlitz, D-02826 Germany ,grid.40602.300000 0001 2158 0612Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, D-01328 Germany
| | - Jan Vorberger
- grid.40602.300000 0001 2158 0612Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, D-01328 Germany
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8
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Pain J. Multi-Configuration Calculation of Ionization Potential Depression. Plasma 2022; 5:384-407. [DOI: 10.3390/plasma5040029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The modelling of ionization potential depression in warm and hot dense plasmas constitutes a real theoretical challenge due to ionic coupling and electron degeneracy effects. In this work, we present a quantum statistical model based on a multi-configuration description of the electronic structure in the framework of Density Functional Theory. We discuss different conceptual issues inherent to the definition of ionization potential depression and compare our results with the famous and widely-used Ecker-Kröll and Stewart-Pyatt models.
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9
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Zan X, Lin C, Hou Y, Yuan J. Local field correction to ionization potential depression of ions in warm or hot dense matter. Phys Rev E 2021; 104:025203. [PMID: 34525605 DOI: 10.1103/physreve.104.025203] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 07/19/2021] [Indexed: 11/07/2022]
Abstract
An analytical self-consistent approach was recently established to predict the ionization potential depression (IPD) in multicomponent dense plasmas, which is achieved by considering the self-energy of ions and electrons within the quantum statistical theory. In order to explicitly account for the exchange-correlation effect of electrons, we incorporate the effective static approximation of local field correction (LFC) within our IPD framework through the connection of dynamical structure factor. The effective static approximation poses an accurate description for the asymptotic large wave number behavior with the recently developed machine learning representation of static LFC induced from the path-integral Monte Carlo data. Our calculation shows that the introduction of static LFC through dynamical structure factor brings a nontrivial influence on IPD at warm/hot dense matter conditions. The correlation effect within static LFC could provide up to 20% correction to free-electron contribution of IPD in the strong coupling and degeneracy regime. Furthermore, a new screening factor is obtained from the density distribution of free electrons calculated within the average-atom model, with which excellent agreements are observed with other methods and experiments at warm/hot dense matter conditions.
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Affiliation(s)
- Xiaolei Zan
- Department of Physics, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha, Hunan 410073, People's Republic of China
| | - Chengliang Lin
- Graduate School of China Academy of Engineering Physics, Beijing 100193, People's Republic of China
| | - Yong Hou
- Department of Physics, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha, Hunan 410073, People's Republic of China
| | - Jianmin Yuan
- Department of Physics, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha, Hunan 410073, People's Republic of China.,Graduate School of China Academy of Engineering Physics, Beijing 100193, People's Republic of China
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10
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Kritcher AL, Swift DC, Döppner T, Bachmann B, Benedict LX, Collins GW, DuBois JL, Elsner F, Fontaine G, Gaffney JA, Hamel S, Lazicki A, Johnson WR, Kostinski N, Kraus D, MacDonald MJ, Maddox B, Martin ME, Neumayer P, Nikroo A, Nilsen J, Remington BA, Saumon D, Sterne PA, Sweet W, Correa AA, Whitley HD, Falcone RW, Glenzer SH. A measurement of the equation of state of carbon envelopes of white dwarfs. Nature 2020; 584:51-54. [DOI: 10.1038/s41586-020-2535-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 05/05/2020] [Indexed: 11/09/2022]
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11
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Abstract
Methane and other hydrocarbons are major components of the mantle regions of icy planets. Several recent computational studies have investigated the high-pressure behaviour of specific hydrocarbons. To develop a global picture of hydrocarbon stability, to identify relevant decomposition reactions, and probe eventual formation of diamond, a complete study of all hydrocarbons is needed. Using density functional theory calculations we survey here all known C-H crystal structures augmented by targeted crystal structure searches to build hydrocarbon phase diagrams in the ground state and at elevated temperatures. We find that an updated pressure-temperature phase diagram for methane is dominated at intermediate pressures by CH 4 :H 2 van der Waals inclusion compounds. We discuss the P-T phase diagram for CH and CH 2 (i.e., polystyrene and polyethylene) to illustrate that diamond formation conditions are strongly composition dependent. Finally, crystal structure searches uncover a new CH 4 (H 2 ) 2 van der Waals compound, the most hydrogen-rich hydrocarbon, stable between 170 and 220 GPa.
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12
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Röpke G, Blaschke D, Döppner T, Lin C, Kraeft WD, Redmer R, Reinholz H. Ionization potential depression and Pauli blocking in degenerate plasmas at extreme densities. Phys Rev E 2019; 99:033201. [PMID: 30999524 DOI: 10.1103/physreve.99.033201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Indexed: 06/09/2023]
Abstract
New facilities explore warm dense matter (WDM) at conditions with extreme densities (exceeding ten times condensed matter densities) so that electrons are degenerate even at temperatures of 10-100 eV. Whereas in the nondegenerate region correlation effects such as Debye screening are relevant for the ionization potential depression (IPD), new effects have to be considered in degenerate plasmas. In addition to the Fock shift of the self-energies, the bound-state Pauli blocking becomes important with increasing density. Standard approaches to IPD such as Stewart-Pyatt and widely used opacity tables (e.g., OPAL) do not contain Pauli blocking effects for bound states. The consideration of degeneracy effects leads to a reduction of the ionization potential and to a higher degree of ionization. As an example, we present calculations for the ionization degree of carbon plasmas at T = 100 eV and extreme densities up to 40 g/cm^{3}, which are relevant to experiments that are currently scheduled at the National Ignition Facility.
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Affiliation(s)
- Gerd Röpke
- Institut für Physik, Universität Rostock, D-18051 Rostock, Germany
- Department of Theoretical Nuclear Physics, National Research Nuclear University (MEPhI), 115409 Moscow, Russia
| | - David Blaschke
- Department of Theoretical Nuclear Physics, National Research Nuclear University (MEPhI), 115409 Moscow, Russia
- Institute of Theoretical Physics, University of Wroclaw, 50-204 Wroclaw, Poland
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - Tilo Döppner
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Chengliang Lin
- Institut für Physik, Universität Rostock, D-18051 Rostock, Germany
| | | | - Ronald Redmer
- Institut für Physik, Universität Rostock, D-18051 Rostock, Germany
| | - Heidi Reinholz
- Institut für Physik, Universität Rostock, D-18051 Rostock, Germany
- School of Physics, University of Western Australia, WA 6009 Crawley, Australia
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13
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Bishel DT, Bachmann B, Yi A, Kraus D, Divol L, Bethkenhagen M, Falcone RW, Fletcher LB, Glenzer SH, Landen OL, MacDonald MJ, Masters N, Neumayer P, Redmer R, Saunders AM, Witte BBL, Döppner T. Using time-resolved penumbral imaging to measure low hot spot x-ray emission signals from capsule implosions at the National Ignition Facility. Rev Sci Instrum 2018; 89:10G111. [PMID: 30399716 DOI: 10.1063/1.5037073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 08/11/2018] [Indexed: 06/08/2023]
Abstract
We have developed and fielded a new x-ray pinhole-imaging snout that exploits time-resolved penumbral imaging of low-emission hot spots in capsule implosion experiments at the National Ignition Facility. We report results for a series of indirectly driven Be capsule implosions that aim at measuring x-ray Thomson scattering (XRTS) spectra at extreme density conditions near stagnation. In these implosions, x-ray emission at stagnation is reduced by 100-1000× compared to standard inertial confinement fusion (ICF) implosions to mitigate undesired continuum background in the XRTS spectra. Our snout design not only enables measurements of peak x-ray emission times, t o , where standard ICF diagnostics would not record any signal, but also allows for inference of hot spot shapes. Measurement of t o is crucial to account for shot-to-shot variations in implosion velocity and therefore to benchmark the achieved plasma conditions between shots and against radiation hydrodynamic simulations. Additionally, we used differential filtering to infer a hot spot temperature of 520 ± 80 eV, which is in good agreement with predictions from radiation hydrodynamic simulations. We find that, despite fluctuations of the x-ray flash intensity of up to 5×, the emission time history is similar from shot to shot and slightly asymmetric with respect to peak x-ray emission.
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Affiliation(s)
- D T Bishel
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - B Bachmann
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A Yi
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D Kraus
- Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - L Divol
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M Bethkenhagen
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R W Falcone
- Physics Department, University of California Berkeley, Berkeley, California 94720, USA
| | - L B Fletcher
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S H Glenzer
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - O L Landen
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M J MacDonald
- Physics Department, University of California Berkeley, Berkeley, California 94720, USA
| | - N Masters
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Neumayer
- GSI Helmholtz-Zentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - R Redmer
- Institut für Physik, Universität Rostock, 18051 Rostock, Germany
| | - A M Saunders
- Physics Department, University of California Berkeley, Berkeley, California 94720, USA
| | - B B L Witte
- Institut für Physik, Universität Rostock, 18051 Rostock, Germany
| | - T Döppner
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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14
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MacDonald MJ, Saunders AM, Falcone RW, Theobald W, Landen OL, Döppner T. Developing a long-duration Zn K- α source for x-ray scattering experiments. Rev Sci Instrum 2018; 89:10F109. [PMID: 30399805 DOI: 10.1063/1.5039365] [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] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/25/2018] [Indexed: 06/08/2023]
Abstract
We are developing a long-duration K-α x-ray source at the Omega laser facility. Such sources are important for x-ray scattering measurements at small scattering angles where high spectral resolution is required. To date, He-α x-ray sources are the most common probes in scattering experiments, using ns-class lasers to heat foils to keV temperatures, resulting in K-shell emission from He-like charge states. The He-α spectrum can be broadened by emission from multiple charge states and lines (e.g., He-like, Li-like, Be-like). Here, we combine the long duration of He-α sources with the narrow spectral bandwidth of cold K-α emission. A Ge foil is irradiated by the Omega laser, producing principally Ge He-α emission, which pumps Zn K-α emission at 8.6 keV from a nearby Zn layer. Using this technique, we demonstrate a long-duration Zn K-α source suitable for scattering measurements. Our experimental results show a 60% reduction in spectral bandwidth compared to a standard Zn He-α source, significantly improving the measurement precision of scattering experiments with small inelastic shifts.
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Affiliation(s)
- M J MacDonald
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - A M Saunders
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - R W Falcone
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - W Theobald
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - O L Landen
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - T Döppner
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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15
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LeFevre HJ, Ma K, Belancourt PX, MacDonald MJ, Döppner T, Huntington CM, Johnsen E, Keiter PA, Kuranz CC. A platform for x-ray Thomson scattering measurements of radiation hydrodynamics experiments on the NIF. Rev Sci Instrum 2018; 89:10F105. [PMID: 30399938 DOI: 10.1063/1.5039392] [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] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/24/2018] [Indexed: 06/08/2023]
Abstract
We present an experimental design for a radiation hydrodynamics experiment at the National Ignition Facility that measures the electron temperature of a shocked region using the x-ray Thomson scattering technique. Previous National Ignition Facility experiments indicate a reduction in Rayleigh-Taylor instability growth due to high energy fluxes, compared to the shocked energy flux, from radiation and electron heat conduction. In order to better quantify the effects of these energy fluxes, we modified the previous experiment to allow for non-collective x-ray Thomson scattering to measure the electron temperature. Photometric calculations combined with synthetic scattering spectra demonstrate an estimated noise.
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Affiliation(s)
- H J LeFevre
- Applied Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109, USA
| | - K Ma
- Mechanical Engineering, University of Michigan, 2350 Hayward Street, Ann Arbor, Michigan 48109, USA
| | - P X Belancourt
- Climate and Space Sciences and Engineering, University of Michigan, 2455 Hayward Street, Ann Arbor, Michigan 48109, USA
| | - M J MacDonald
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - T Döppner
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - C M Huntington
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - E Johnsen
- Mechanical Engineering, University of Michigan, 2350 Hayward Street, Ann Arbor, Michigan 48109, USA
| | - P A Keiter
- Climate and Space Sciences and Engineering, University of Michigan, 2455 Hayward Street, Ann Arbor, Michigan 48109, USA
| | - C C Kuranz
- Climate and Space Sciences and Engineering, University of Michigan, 2455 Hayward Street, Ann Arbor, Michigan 48109, USA
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16
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Döppner T, Swift DC, Kritcher AL, Bachmann B, Collins GW, Chapman DA, Hawreliak J, Kraus D, Nilsen J, Rothman S, Benedict LX, Dewald E, Fratanduono DE, Gaffney JA, Glenzer SH, Hamel S, Landen OL, Lee HJ, LePape S, Ma T, MacDonald MJ, MacPhee AG, Milathianaki D, Millot M, Neumayer P, Sterne PA, Tommasini R, Falcone RW. Absolute Equation-of-State Measurement for Polystyrene from 25 to 60 Mbar Using a Spherically Converging Shock Wave. Phys Rev Lett 2018; 121:025001. [PMID: 30085737 DOI: 10.1103/physrevlett.121.025001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 05/01/2018] [Indexed: 06/08/2023]
Abstract
We have developed an experimental platform for the National Ignition Facility that uses spherically converging shock waves for absolute equation-of-state (EOS) measurements along the principal Hugoniot. In this Letter, we present one indirect-drive implosion experiment with a polystyrene sample that employs radiographic compression measurements over a range of shock pressures reaching up to 60 Mbar (6 TPa). This significantly exceeds previously published results obtained on the Nova laser [R. Cauble et al., Phys. Rev. Lett. 80, 1248 (1998)PRLTAO0031-900710.1103/PhysRevLett.80.1248] at a strongly improved precision, allowing us to discriminate between different EOS models. We find excellent agreement with Kohn-Sham density-functional-theory-based molecular dynamics simulations.
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Affiliation(s)
- T Döppner
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D C Swift
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A L Kritcher
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - B Bachmann
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G W Collins
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
- Department of Mechanical Engineering, Physics and Astronomy, University of Rochester, Rochester, New York 14623, USA
| | - D A Chapman
- AWE plc, Aldermaston RG7 4PR, United Kingdom
| | - J Hawreliak
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D Kraus
- University of California, Berkeley, California 94720, USA
- Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - J Nilsen
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S Rothman
- AWE plc, Aldermaston RG7 4PR, United Kingdom
| | - L X Benedict
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E Dewald
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D E Fratanduono
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J A Gaffney
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S H Glenzer
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Hamel
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - O L Landen
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - H J Lee
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S LePape
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - T Ma
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M J MacDonald
- University of California, Berkeley, California 94720, USA
| | - A G MacPhee
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D Milathianaki
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M Millot
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Neumayer
- GSI Helmholtz-Zentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - P A Sterne
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R Tommasini
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R W Falcone
- University of California, Berkeley, California 94720, USA
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17
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Kasim MF, Wark JS, Vinko SM. Validating Continuum Lowering Models via Multi-Wavelength Measurements of Integrated X-ray Emission. Sci Rep 2018; 8:6276. [PMID: 29674688 DOI: 10.1038/s41598-018-24410-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 03/26/2018] [Indexed: 11/11/2022] Open
Abstract
X-ray emission spectroscopy is a well-established technique used to study continuum lowering in dense plasmas. It relies on accurate atomic physics models to robustly reproduce high-resolution emission spectra, and depends on our ability to identify spectroscopic signatures such as emission lines or ionization edges of individual charge states within the plasma. Here we describe a method that forgoes these requirements, enabling the validation of different continuum lowering models based solely on the total intensity of plasma emission in systems driven by narrow-bandwidth x-ray pulses across a range of wavelengths. The method is tested on published Al spectroscopy data and applied to the new case of solid-density partially-ionized Fe plasmas, where extracting ionization edges directly is precluded by the significant overlap of emission from a wide range of charge states.
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18
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Zhang S, Militzer B, Benedict LX, Soubiran F, Sterne PA, Driver KP. Path integral Monte Carlo simulations of dense carbon-hydrogen plasmas. J Chem Phys 2018; 148:102318. [DOI: 10.1063/1.5001208] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Shuai Zhang
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Burkhard Militzer
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
- Department of Astronomy, University of California, Berkeley, California 94720, USA
| | - Lorin X. Benedict
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - François Soubiran
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
| | - Philip A. Sterne
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Kevin P. Driver
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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19
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Lin C, Röpke G, Kraeft WD, Reinholz H. Ionization-potential depression and dynamical structure factor in dense plasmas. Phys Rev E 2017; 96:013202. [PMID: 29347154 DOI: 10.1103/physreve.96.013202] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Indexed: 06/07/2023]
Abstract
The properties of a bound electron system immersed in a plasma environment are strongly modified by the surrounding plasma. The modification of an essential quantity, the ionization energy, is described by the electronic and ionic self-energies, including dynamical screening within the framework of the quantum statistical theory. Introducing the ionic dynamical structure factor as the indicator for the ionic microfield, we demonstrate that ionic correlations and fluctuations play a critical role in determining the ionization potential depression. This is, in particular, true for mixtures of different ions with large mass and charge asymmetry. The ionization potential depression is calculated for dense aluminum plasmas as well as for a CH plasma and compared to the experimental data and more phenomenological approaches used so far.
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Affiliation(s)
- Chengliang Lin
- Universität Rostock, Institut für Physik, 18051 Rostock, Germany
| | - Gerd Röpke
- Universität Rostock, Institut für Physik, 18051 Rostock, Germany
| | | | - Heidi Reinholz
- Universität Rostock, Institut für Physik, 18051 Rostock, Germany
- University of Western Australia School of Physics, WA 6009 Crawley, Australia
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20
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Zhang S, Driver KP, Soubiran F, Militzer B. First-principles equation of state and shock compression predictions of warm dense hydrocarbons. Phys Rev E 2017; 96:013204. [PMID: 29347225 DOI: 10.1103/physreve.96.013204] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Indexed: 06/07/2023]
Abstract
We use path integral Monte Carlo and density functional molecular dynamics to construct a coherent set of equations of state (EOS) for a series of hydrocarbon materials with various C:H ratios (2:1, 1:1, 2:3, 1:2, and 1:4) over the range of 0.07-22.4gcm^{-3} and 6.7×10^{3}-1.29×10^{8}K. The shock Hugoniot curve derived for each material displays a single compression maximum corresponding to K-shell ionization. For C:H = 1:1, the compression maximum occurs at 4.7-fold of the initial density and we show radiation effects significantly increase the shock compression ratio above 2 Gbar, surpassing relativistic effects. The single-peaked structure of the Hugoniot curves contrasts with previous work on higher-Z plasmas, which exhibit a two-peak structure corresponding to both K- and L-shell ionization. Analysis of the electronic density of states reveals that the change in Hugoniot structure is due to merging of the L-shell eigenstates in carbon, while they remain distinct for higher-Z elements. Finally, we show that the isobaric-isothermal linear mixing rule for carbon and hydrogen EOS is a reasonable approximation with errors better than 1% for stellar-core conditions.
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Affiliation(s)
- Shuai Zhang
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
| | - Kevin P Driver
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
| | - François Soubiran
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
| | - Burkhard Militzer
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA and Department of Astronomy, University of California, Berkeley, California 94720, USA
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21
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Saunders AM, Jenei A, Döppner T, Falcone RW, Kraus D, Kritcher A, Landen OL, Nilsen J, Swift D. X-ray Thomson scattering measurements from hohlraum-driven spheres on the OMEGA laser. Rev Sci Instrum 2016; 87:11E724. [PMID: 27910609 DOI: 10.1063/1.4962044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
X-ray Thomson scattering (XRTS) is a powerful diagnostic for probing warm and hot dense matter. We present the design and results of the first XRTS experiments with hohlraum-driven CH2 targets on the OMEGA laser facility at the Laboratory for Laser Energetics in Rochester, NY. X-rays seen directly from the XRTS x-ray source overshadow the elastic scattering signal from the target capsule but can be controlled in future experiments. From the inelastic scattering signal, an average plasma temperature is inferred that is in reasonable agreement with the temperatures predicted by simulations. Knowledge gained in this experiment shows a promising future for further XRTS measurements on indirectly driven OMEGA targets.
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Affiliation(s)
- A M Saunders
- University of California Berkeley, Berkeley, California 94720, USA
| | - A Jenei
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - T Döppner
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - R W Falcone
- University of California Berkeley, Berkeley, California 94720, USA
| | - D Kraus
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - A Kritcher
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - O L Landen
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - J Nilsen
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - D Swift
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
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22
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Döppner T, Kraus D, Neumayer P, Bachmann B, Emig J, Falcone RW, Fletcher LB, Hardy M, Kalantar DH, Kritcher AL, Landen OL, Ma T, Saunders AM, Wood RD. Improving a high-efficiency, gated spectrometer for x-ray Thomson scattering experiments at the National Ignition Facility. Rev Sci Instrum 2016; 87:11E515. [PMID: 27910303 DOI: 10.1063/1.4959874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We are developing x-ray Thomson scattering for applications in implosion experiments at the National Ignition Facility. In particular we have designed and fielded MACS, a high-efficiency, gated x-ray spectrometer at 7.5-10 keV [T. Döppner et al., Rev. Sci. Instrum. 85, 11D617 (2014)]. Here we report on two new Bragg crystals based on Highly Oriented Pyrolytic Graphite (HOPG), a flat crystal and a dual-section cylindrically curved crystal. We have performed in situ calibration measurements using a brass foil target, and we used the flat HOPG crystal to measure Mo K-shell emission at 18 keV in 2nd order diffraction. Such high photon energy line emission will be required to penetrate and probe ultra-high-density plasmas or plasmas of mid-Z elements.
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Affiliation(s)
- T Döppner
- Lawrence Livermore National Laboratory, Livermore, California 94720, USA
| | - D Kraus
- University of California, Berkeley, California 94720, USA
| | - P Neumayer
- Gesellschaft für Schwerionenphysik, Darmstadt, Germany
| | - B Bachmann
- Lawrence Livermore National Laboratory, Livermore, California 94720, USA
| | - J Emig
- Lawrence Livermore National Laboratory, Livermore, California 94720, USA
| | - R W Falcone
- University of California, Berkeley, California 94720, USA
| | - L B Fletcher
- SLAC National Accelerator Laboratory, Menlo Park, California 94720, USA
| | - M Hardy
- Lawrence Livermore National Laboratory, Livermore, California 94720, USA
| | - D H Kalantar
- Lawrence Livermore National Laboratory, Livermore, California 94720, USA
| | - A L Kritcher
- Lawrence Livermore National Laboratory, Livermore, California 94720, USA
| | - O L Landen
- Lawrence Livermore National Laboratory, Livermore, California 94720, USA
| | - T Ma
- Lawrence Livermore National Laboratory, Livermore, California 94720, USA
| | - A M Saunders
- University of California, Berkeley, California 94720, USA
| | - R D Wood
- Lawrence Livermore National Laboratory, Livermore, California 94720, USA
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23
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Dharuman G, Verboncoeur J, Christlieb A, Murillo MS. Atomic bound state and scattering properties of effective momentum-dependent potentials. Phys Rev E 2016; 94:043205. [PMID: 27841554 DOI: 10.1103/physreve.94.043205] [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: 06/01/2016] [Indexed: 06/06/2023]
Abstract
Effective classical dynamics provide a potentially powerful avenue for modeling large-scale dynamical quantum systems. We have examined the accuracy of a Hamiltonian-based approach that employs effective momentum-dependent potentials (MDPs) within a molecular-dynamics framework through studies of atomic ground states, excited states, ionization energies, and scattering properties of continuum states. Working exclusively with the Kirschbaum-Wilets (KW) formulation with empirical MDPs [C. L. Kirschbaum and L. Wilets, Phys. Rev. A 21, 834 (1980)0556-279110.1103/PhysRevA.21.834], optimization leads to very accurate ground-state energies for several elements (e.g., N, F, Ne, Al, S, Ar, and Ca) relative to Hartree-Fock values. The KW MDP parameters obtained are found to be correlated, thereby revealing some degree of transferability in the empirically determined parameters. We have studied excited-state orbits of electron-ion pair to analyze the consequences of the MDP on the classical Coulomb catastrophe. From the optimized ground-state energies, we find that the experimental first- and second-ionization energies are fairly well predicted. Finally, electron-ion scattering was examined by comparing the predicted momentum transfer cross section to a semiclassical phase-shift calculation; optimizing the MDP parameters for the scattering process yielded rather poor results, suggesting a limitation of the use of the KW MDPs for plasmas.
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Affiliation(s)
- Gautham Dharuman
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824, USA
| | - John Verboncoeur
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, Michigan 48824, USA
| | - Andrew Christlieb
- Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Mathematics, Michigan State University, East Lansing, Michigan 48824, USA
| | - Michael S Murillo
- New Mexico Consortium, Los Alamos, New Mexico 87544, USA
- Computational Physics and Methods Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
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24
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Wang Z, Fu Z, He B, Hu Z, Zhang P. Nuclear-plus-interference-scattering effect on the energy deposition of multi-MeV protons in a dense Be plasma. Phys Rev E 2016; 94:033205. [PMID: 27739783 DOI: 10.1103/physreve.94.033205] [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: 02/01/2016] [Indexed: 06/06/2023]
Abstract
The nuclear plus interference scattering (NIS) effect on the stopping power of hot dense beryllium (Be) plasma for multi-MeV protons is theoretically investigated by using the generalized Brown-Preston-Singleton (BPS) model, in which a NIS term is taken into account. The analytical formula of the NIS term is detailedly derived. By using this formula, the density and temperature dependence of the NIS effect is numerically studied, and the results show that the NIS effect becomes more and more important with increasing the plasma temperature or density. Different from the cases of protons traveling through the deuterium-tritium plasmas, for a Be plasma, a prominent oscillation valley structure is observed in the NIS term when the proton's energy is close to E_{p}=7MeV. Furthermore, the penetration distance is remarkably reduced when the NIS term is considered.
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Affiliation(s)
- Zhigang Wang
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - Zhenguo Fu
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
- Center for Fusion Energy Science and Technology, CAEP, Beijing 100088, China
| | - Bin He
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - Zehua Hu
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - Ping Zhang
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
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