# Equation of state for dense hydrogen and plasma phase transition

## TL;DR

This paper develops an equation of state for dense hydrogen considering dissociation and ionization, identifies a plasma phase transition, and applies the data to planetary interior modeling.

## Contribution

It generalizes fluid variational theory for a multi-component system and links the plasma phase transition to thermodynamic instability.

## Key findings

- Identified the plasma phase transition region.
- Calculated reflectivity along the Hugoniot curve.
- Applied EOS data to Jupiter's interior modeling.

## Abstract

We calculate the equation of state of dense hydrogen within the chemical picture. Fluid variational theory is generalized for a multi-component system of molecules, atoms, electrons, and protons. Chemical equilibrium is supposed for the reactions dissociation and ionization. We identify the region of thermodynamic instability which is related to the plasma phase transition. The reflectivity is calculated along the Hugoniot curve and compared with experimental results. The equation-of-state data is used to calculate the pressure and temperature profiles for the interior of Jupiter.