Microfield Fluctuations and Spectral Line Shapes in Strongly Coupled Two–Component Plasmas

Nersisyan, Hrachya B.; Toepffer, C.; Zwicknagel, G.

doi:10.1002/ctpp.201010034

Cited by 7 publications

(4 citation statements)

References 48 publications

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“…The former is now a well-established prescription [12], while the latter is still a developing research area. Recent surveys and conference proceedings [13][14][15] highlight several interesting MD investigations relevant to microfields [e.g., [16][17][18][19]. However, the limited scope and modest computational size typical of these simulations limit their ability to reveal trends involving different plasma conditions, or to obtain reliable information about statistically improbable parameter regimes.…”

Section: Introductionmentioning

confidence: 99%

Electric microfields in dense carbon-hydrogen plasmas

Hau‐Riege

Weisheit

2015

Phys. Rev. E

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Classical molecular dynamics is used to investigate stationary and time-dependent properties of microfields in hot, solid density, electron-ion plasmas. Even at the high temperatures considered here, such simulations require quantum statistical potentials (QSPs) to mimic the essential effects of diffraction and exchange symmetry for electrons. Fortunately, key results relevant to microfield distributions are found to be insensitive to different, plausible QSP choices. Atomic processes in plasmas will depend on the time average of the microfields. It is not clear, a priori, what the time duration of this average should be. The question of how best to extract the quasistatic (low-frequency) microfield from a classical molecular dynamics simulation is explored in some detail, and the time-averaging approach we adopt involves both plasma and atomic time scale constraints. One of the major findings described in the paper is that for a large time interval, the time-averaged microfield does not significantly change. Our discussion of this suite of large simulations for plasma mixtures focuses on understanding various features and trends revealed by data for C-H plasmas having carbon fractions ranging from 0.01 to 1, and different temperatures well above TFermi.

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Section: Introductionmentioning

confidence: 99%

Electric microfields in dense carbon-hydrogen plasmas

Hau‐Riege

Weisheit

2015

Phys. Rev. E

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“…Although mainly performed in the context of fully ionized two-component plasmas, all this work enabled the study of electric microfield issues beyond the capability of most theoretical methods. Furthermore, full MD simulations have been used in several works to carry out elaborate calculations of Stark-broadened line profiles in hydrogenic plasmas [14,[26][27][28].…”

Section: Introductionmentioning

confidence: 99%

“…Also, when simulating plasma particle dynamics, several papers [20,[28][29][30][31][32] have discussed the difficulty in dealing with the situation in which an electron is trapped by a charged ion, which may restrict the model applicability to the weakcoupling regime. In this context a few works used MD techniques to model the plasma ionization balance, i.e., including the ionization-recombination mechanism [33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Classical molecular dynamics simulations of hydrogen plasmas and development of an analytical statistical model for computational validity assessment

González-Herrero

Lara

et al. 2018

Phys. Rev. E

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Classical molecular dynamics simulations of hydrogen plasmas have been performed with an emphasis on the analysis of the equilibration process. The theoretical basis of the simulation model as well as numerically relevant aspects, such as the proper choice and definition of simulation units, are discussed in detail, thus proving a thorough implementation of the computer simulation technique. Because of the lack of experimental data, molecular dynamics simulations are often considered as idealized computational experiments for benchmarking of theoretical models. However, these simulations are certainly challenging and consequently a validation procedure is also demanded. In this work we develop an analytical statistical equilibrium model for computational validity assessment of plasma particle dynamics simulations. Remarkable agreement between model and molecular dynamics results including a classical treatment of the ionization-recombination mechanism is obtained for a wide range of plasma coupling parameter values. Furthermore, the analytical model provides guidance to securely terminate simulation runs once the equilibrium stage has been reached, which in turn gives confidence in the statistics that potentially may be extracted from time histories of simulated physical quantities.

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“…The distribution function of a low-frequency ionic microfield in an ideal homogeneous plasma was obtained by Holtsmark [1]. Attempts to take into account correlation effects between particles were made in [2][3][4][5][6][7][8][9][10][11] (see also reviews [12,13]). In our papers [14,15], we used the molecular dynamics method in order to calculate the distribution functions of the ionic microfield for a two-component singly and multiply ionized unbounded homogeneous plasma at neutral and positively charged points depending on the strong coupling parameter.…”

mentioning

confidence: 99%