Plasma Phase Transition in Fluid Hydrogen‐Helium Mixtures

Abstract

SummaryThe composition andiihe equation of state for a binary mixture of dense partially ionized hydrogen and helium are investigated on the basis of quantum statistical theory. Theoretical evidence for the existence of a hydrogen-like and helium-like plasma phase transition is found. Critical data for the phase transitions are given for the whole range of the mixing parameter.

Thermodynamics of Hydrogen and Hydrogen‐Helium Plasmas: Path Integral Monte Carlo Calculations and Chemical Picture

“…Earlier we found a similar effect for pure hydrogen at T = 10 4 K in the region of pressure ionization and showed that in the transition region a number of large clusters (droplets) were formed [26,27]. In this region of pressure ionization the PPT was predicted by many authors [6,7,[9][10][11][28][29][30] and moreover a sharp electrical conductivity rise was measured in [31]. The instabilities in our calculations indicate the existence of PPT in dense hydrogen.…”

“…At low temperatures T = 10 4 and 2 · 10 4 K we can observe the formation of large clusters of atoms and molecules. The problem of PPT in a hydrogen-helium mixture is significantly determined by the composition of the mixture [2,7,30]. From shock-wave experiments one can estimate the range of temperature and density where a sharp electrical conductivity rise takes place.…”

“…However it is not enough to determine the region of existence of the PPT. According to theoretical equations of state the critical point of the PPT in pure hydrogen is T crH ∼ 12 − 19 kK, P crH ∼ 0.2 − 0.9 Mbar [2,7,30,36]. In pure helium the critical point was found to be T crHe ∼ 17 kK [30] or T crHe ∼ 35 kK [36] and P crHe ∼ 7 Mbar [30,36].…”

Correlation effects in partially ionized mass asymmetric electron-hole plasmas

“…Electron-hole droplet formation in semiconductors is well established and was observed experimentally three decades ago 15 . This effect is similar to the so-called plasma phase transition discussed by many authors for dense hydrogen and other plasmas (see 45,46,47,48,49 and references therein). Figure 7 shows snapshots of the electron-hole configuration in the simulation box at different temperatures and densities.…”

Thermodynamics of hot dense H-plasmas: path integral Monte Carlo simulations and analytical approximations

“…the degree of ionization is larger than 75%. The description of the region where a higher percentage of atoms and, due to this, also molecules is present needs a more refined chemical picture [7,47,48]. Finally, we compare the Padé and PIMC data along the isotherm T = 50, 000K which is given in Fig.…”