Magnetothermodynamics: Measuring equations of state in a relaxed magnetohydrodynamic plasma

TL;DR

This study measures the equations of state in a relaxed magnetohydrodynamic plasma, revealing discrepancies with theoretical MHD predictions, thus advancing understanding of plasma thermodynamics.

Contribution

First experimental measurement of equations of state in a fully relaxed MHD plasma, testing theoretical models against real data.

Findings

MHD equation of state does not match experimental data

Density, ion temperature, and magnetic field are measured during plasma relaxation

Experimental results challenge existing theoretical assumptions

Abstract

We report the first measurements of equations of state of a fully relaxed magnetohydrodynamic (MHD) laboratory plasma. Parcels of magnetized plasma, called Taylor states, are formed in a coaxial magnetized plasma gun, and are allowed to relax and drift into a closed flux conserving volume. Density, ion temperature, and magnetic field are measured as a function of time as the Taylor states compress and heat. The theoretically predicted MHD and double adiabatic equations of state are compared to experimental measurements. We find that the MHD equation of state is inconsistent with our data.