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## Плазменный фазовый переход

Успехи физических наук. 2021. Т. 191. № 11. С. 1153-1186.

Norman G., Saitov I.

Recently developed experimental methods for the generation and diagnostics of nonideal plasma and warm dense

matter are reviewed. Modern theoretical methods applied to solve the problem of fluid±fluid phase transitions, including the plasma phase transition, are considered. Quantum simulation methods and the results obtained in the chemical model of plasma are analyzed. Particular attention is paid to the phase transition in warm dense hydrogen/deuterium at high pressures.Results for helium, aluminum, cesium, cerium, ionic, and exciton plasmas and some other substances are also considered.

Lavrinenko Y. S., Morozov I.V., Valuev I. A., Contributions to Plasma Physics 2016 Vol. 56 P. 448-458

The influence of boundary conditions for the classical and wave packet molecular dynamics (MD) simulations of nonideal electron-ion plasma is studied. We start with the classical MD and perform a comprehensive study of convergence of the per-particle potential energy and pressure with the number of particles using both the nearest image method (periodic boundaries) and ...

Added: June 28, 2016

Norman G., Saitov I., Stegailov V., Contributions to Plasma Physics 2015 Vol. 55 No. 2-3 P. 215-221

Ab initio quantum modeling is applied to check the ideas that motivated studies of both plasma phase transition (PPT) and Brazhkin semiconductor-to-metal phase transition, and to analyze both similarity and difference between them as well as with the Wigner metallization. Electron density of states and the characteristic gap in it are investigated to verify the ...

Added: March 15, 2017

Bystryi R.G., Morozov I.V., Journal of Physics B: Atomic, Molecular and Optical Physics 2015 Vol. 48 No. 01-5401 P. 1-7

Irradiation of nanosized metallic clusters by femtosecond laser pulses of moderate intensities (10^12 – 10^14 W/cm^2) leads to creation of the so-called electron–ion nanoplasma with size-dependent properties. Electron oscillations in such plasma are of interest in view of resonance absorption or probing of cluster dynamics in experiments. We study the electronic oscillations via molecular dynamics ...

Added: December 25, 2014

Norman G., Saitov I., Доклады Российской академии наук. Физика, технические науки (ранее - Доклады Академии Наук. Физика) 2017 Т. 474 № 5 С. 553-557

The problem of the fluid–fluid phase transition in warm dense hydrogen/deuterium has been studied experimentally and theoretically in the best laboratories in the last decade. However, the nature of the phase transition remains unclarified. In this paper we put forward the new idea that H2 molecules are ionized at the phase transition to produce molecular ...

Added: December 2, 2017

Stegailov V., Zhilyaev P. A., Contributions to Plasma Physics 2015 Vol. 55 No. 2-3 P. 164-171

Non-equilibrium two-temperature warm dense metals consist of the ion subsystem that is subjected to structural transitions and involved in the mass transfer, and the electron subsystem that in various pulsed experiments absorbs energy and then evolves together with ions to equilibrium. Definition of pressure in such non-equilibrium systems causes certain controversy. In this work we ...

Added: March 15, 2017

Norman G., Saitov I., Доклады Российской академии наук. Физика, технические науки (ранее - Доклады Академии Наук. Физика) 2017 Т. 474 № 6 С. 687-691

The density functional theory is used to calculate the equation of state and the proton-proton pair correlation functions in the range of hydrogen temperatures and densities where the fluid-fluid-phase transition is expected. The metastable states are considered. The critical temperature has been estimated to be ~4000 K. We propose a two-step mechanism: the partial ionization ...

Added: December 2, 2017

Norman G., Saitov I., Stegailov V. et al., Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2015 Vol. 91 No. 023105 P. 1-10

Reflectivity of shocked compressed xenon plasma is calculated within the framework of the density functional theory approach. Dependencies on the frequency of incident radiation and on the plasma density are analyzed. The Fresnel formula for the reflectivity is used. The longitudinal expression in the long-wavelength limit is applied for the calculation of the imaginary part ...

Added: March 15, 2017

Быстрый Р.Г., Лавриненко Я. С., Ланкин А. В. et al., Теплофизика высоких температур 2014 Т. 52 № 4 С. 494-503

Pressure fluctuations in equilibrium nonideal plasma are investigated by the method of classical molecular dynamics. Examples of plasma parameters at which the pressure fluctuation distribution function is not normal but can be approximated by the sum of two normal distributions were found. The electron-ion interaction is described by the Coulomb potential cutoff at the depth ...

Added: December 25, 2014

Norman G., Saitov I., Journal of Physics: Conference Series 2018 Vol. 946 No. 012121

A new idea is developed that the fluid–fluid phase transition in warm dense hydrogen is related to the partial ionization of molecular hydrogen H2 with formation of molecular ions H2+ and H3+ . Conventional ab initio quantum modeling is applied. Proton pair correlation functions (PCF) obtained are used for the nonconventional diagnostics of the phase ...

Added: November 29, 2017

Norman G., Saitov I., Contributions to Plasma Physics 2018 Vol. 58 No. 2-3 P. 122-127

A new idea is developed that the fluid–fluid phase transition in warm dense hydrogen
is related to the partial ionization of molecular hydrogen H2 with formation of
molecular ions H+2 and H+3 . Conventional ab initio quantum modelling is applied.
The proton–proton pair correlation functions (PCFs) obtained are used for the
non-conventional diagnostics of the phase transition and elucidation ...

Added: June 8, 2018

Morozov I., Valuev I. A., Journal of Physics A: Mathematical and Theoretical 2009 Vol. 42 P. 214044

The problem ofwave packet broadening in themethod ofwave packet molecular dynamics simulations of electron–ion nonideal plasmas is discussed. It is shown that when using a harmonic restrictive potential for the packet widths, simulation results depend strongly on the constraint parameter. Two new approaches to constraining the packet broadening in a less stringent way are analyzed: ...

Added: March 14, 2014

Raitza T., Reinholz H., Roepke G. et al., Journal of Physics A: Mathematical and Theoretical 2009 Vol. 42 P. 214048

Laser excited small metallic clusters are simulated using classical pseudo potential molecular dynamics simulations. Time-dependent distribution functions are obtained from the electron and ion trajectories in order to investigate plasma properties. The question of local thermodynamic equilibrium is addressed, and size effects are considered. Results for the electron distribution in phase space are given, which ...

Added: March 14, 2014

Morozov I., Reinholz H., Roepke G. et al., Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2005 Vol. 71 P. 066408

The optical conductivity for dense Coulomb systems is investigated using molecular dynamics simulations
on the basis of pseudopotentials to mimic quantum effects. Starting from linear response theory, the
response in the long-wavelength limit k=0 can be expressed by different types of autocorrelation functions
sACF’sd such as the current ACF, the force ACF, or the charge density ACF. Consistent ...

Added: March 14, 2014

Saitov I., Molecular Physics 2016 Vol. 114 No. 3-4 P. 446-452

Density functional theory (DFT) is applied for the calculation of the dielectric function (DF), reflectivity,
conductivity, plasma frequency and effective free electron density of warm dense matter
(WDM). Shock-compressed xenon plasma and warm dense hydrogen are considered. The longitudinal
expression in the long wavelength limit is applied for the calculation of the imaginary part of
the DF. The real ...

Added: March 30, 2017

Stegailov V., Zhilyaev P., Molecular Physics 2016 Vol. 114 No. 3-4 P. 509-518

Warm dense matter is a peculiar state with solid densities and temperatures 1 − 100 eV. Its ab initio description waits united efforts of quantum chemistry, condensed matter and plasma physics. We use the finite temperature Kohn–Sham density functional theory (a ‘workhorse’ in this field) to study the pressure build-up with increase of electronic temperature in ...

Added: July 5, 2016

Zhilyaev P., Norman G., Stegailov V., Doklady Physics 2013 Vol. 58 No. 8 P. 334-338

Warm dense matter (WDM) is a state of a substance with a solid-state density and temperature from 1 to 100 eV. Researchers believe that such a state exists in the cores of giant planets. Investigation of WDM is important for some applications, such as surface treatment on the nanometer scale, laser ablation, and the formation ...

Added: March 19, 2014

Norman G., Saitov I., Contributions to Plasma Physics 2019 Vol. 59 No. 6 P. e201800182

At first, we present a brief review of the problem. Then, we consider plasma phase transition (PPT) as a mechanism of the first order fluid–fluid phase transition in warm dense hydrogen. The pros and cons are analysed. The properties of warm dense hydrogen are investigated by ab initio methods of molecular dynamics using the density ...

Added: October 30, 2019

Norman G., Saitov I., Sartan R., Interfacial Phenomena and Heat Transfer 2017 Vol. 5 No. 3 P. 165-171

Warm dense hydrogen is investigated by ab initio molecular dynamics simulations in the region of fluid–fluid phase
transition. The method of getting adjacent metastable states is developed. The metastable states are successfully obtained in the region of densities from 0.920 to 0.970 g/cm3 and pressures from 1850 kbar to 2150 kbar along an example of 1000K ...

Added: June 15, 2018

Morozov I., Норман Г. Э., Журнал экспериментальной и теоретической физики 2005 Т. 127 № 2 С. 412-430

Плазменные волны и характер столкновений частиц в равновесной двухкомпонентной неидеальной плазме, состоящей из невырожденных электронов и однократно заряженных ионов, рассмотрены на основе моделирования методом молекулярной динамики (МД). Определены дисперсия частоты и декремента затухания ленгмюровских волн. Указан метод обобщения теории плазменных волн в идеальной плазме для расширения области применимости теории в сторону неидеальной плазмы. Определены проводимость ...

Added: March 14, 2014

Lankin A. V., Morozov I., Norman G. E. et al., Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2009 Vol. 79 P. 036407

A plasma model of relaxation of a medium in heavy-ion tracks in condensed matter is proposed. The model is based on three assumptions: the Maxwell distribution of plasma electrons, localization of plasma inside the track nanochannel, and constant values of the plasma electron density and temperature during the x-ray irradiation. The model of multiple ionization ...

Added: March 14, 2014

Norman G., Saitov I., Sartan R., Journal of Physics: Conference Series 2019 Vol. 1147 No. 012003 P. 1-6

The warm dense hydrogen is studied by means of the ab initio molecular dynamics
simulation in the region of fluid–fluid phase transition. The metastable states of two isotherm
of 700 and 1000 K are calculated. The metastable ranges by pressure are 470 and 320 kbar
respectively. The existence of metastability is a strong criterion that the transition is ...

Added: October 30, 2019

Norman G., Saitov I., Journal of Physics: Conference Series 2016 Vol. 774 No. 012015 P. 1-8

An analysis is presented of experimental data where fluid–fluid phase transitions are observed for different substances at high temperatures with triple points on melting curves. Viscosity drops point to the structural character of the transition, whereas conductivity jumps remind of both semiconductor-to-metal and plasma nature. The slope of the phase equilibrium dependencies of pressure on ...

Added: March 30, 2017

Norman G., Saitov I., Stegailov V. et al., Contributions to Plasma Physics 2013 Vol. 53 No. 4-5 P. 300-310

Warm dense matter conductivity and reflectivity are investigated by means of density functional theory. Both one- and two-temperature cases are considered. One-temperature mode is related to equilibrium state where temperature of electrons and ions are equal. As an example of one-temperature system xenon plasma is studied. The reflectivity of shock-compressed dense xenon plasma is calculated ...

Added: March 19, 2014

Katushkina O. A., Quemerais E., Izmodenov V.V. et al., JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 2017 Vol. 122 No. 11 P. 10921-10937

In this work, we present for the first time the Lyman α intensities measured by Voyager 1/UVS in 2003–2014 (at 90–130 AU from the Sun). During this period Voyager 1 measured the Lyman α emission in the outer heliosphere at an almost fixed direction close to the upwind (i.e.“ toward the interstellar flow). The data show an unexpected behavior in 2003–2009: the ...

Added: January 26, 2018