The magnetothermodynamics of compressed turbulent MHD plasmas for MIF

We will provide an overview of magneto-inertial fusion-related studies of what we call magnetothermodynamics on compressed Taylor states at SSX. Our goal for the ALPHA project has been to accelerate a Taylor state to high velocity, then stagnate and compress the object into a suitable MIF target. We have characterized the magnetic structure, velocity, density ($0.5 \times 10^{16}~cm^{-3}$), proton temperature ($20~eV$), and magnetic field ($0.4~T$) of relaxed helical Taylor states. Since we measure proton pressure ($P = nkT$) and volume as a function of time, we can construct $PV$ diagrams, and measure equations of state. Recently, we have been focussing increasing the Taylor state lifetime, primarily by increasing electron temperature. We estimate $T_e$ with a VUV spectrometer measurement of the ratio of the $C_{III}$ to $C_{IV}$ line intensities. We have also begun studies of the temporal evolution of our Taylor state in the SSX MHD wind tunnel from an axisymmetric compact spheromak to an elongated Taylor state using the Dedalus framework. The EOS for our compression experiments is sensitive to proton dynamics along and across field lines, so we are also simulating particle orbits in the Taylor state geometry.