Phase separation in hydrogen-helium mixtures at Mbar pressures

被引：107

作者：

Morales, Miguel A. ^{[1
]}

Schwegler, Eric ^{[4
]}

Ceperley, David ^{[1
,2
,3
]}

Pierleoni, Carlo ^{[3
,5
,6
]}

Hamel, Sebastien ^{[4
]}

Caspersen, Kyle ^{[4
]}

机构：

[1] Univ Illinois, Dept Phys, Urbana, IL 61801 USA

[2] Univ Illinois, Natl Ctr Supercomp Applicat, Urbana, IL 61801 USA

[3] Univ Illinois, Inst Condensed Matter Theory, Urbana, IL 61801 USA

[4] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA

[5] Univ Aquila, Consorzio Nazl Interuniv Sci Fis Mat, I-67100 Laquila, Italy

[6] Univ Aquila, Dept Phys, I-67100 Laquila, Italy

来源：

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA | 2009年 / 106卷 / 05期

关键词：

ab initio molecular dynamics; high pressure; planetary interiors; GIANT PLANETS; FLUID; EVOLUTION; JUPITER; STARS;

D O I：

10.1073/pnas.0812581106

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

The properties of hydrogen-helium mixtures at Mbar pressures and intermediate temperatures (4000 to 10000 K) are calculated with first-principles molecular dynamics simulations. We determine the equation of state as a function of density, temperature, and composition and, using thermodynamic integration, we estimate the Gibbs free energy of mixing, thereby determining the temperature, at a given pressure, when helium becomes insoluble in dense metallic hydrogen. These results are directly relevant to models of the interior structure and evolution of Jovian planets. We find that the temperatures for the demixing of helium and hydrogen are sufficiently high to cross the planetary adiabat of Saturn at pressures approximate to 5 Mbar; helium is partially miscible throughout a significant portion of the interior of Saturn, and to a lesser extent in Jupiter.

引用

页码：1324 / 1329

页数：6

共 24 条

[1] A quantum fluid of metallic hydrogen suggested by first-principles calculations [J].