Characterization of Taylor plumes on SSX

We have added a $1~m$ glass extension to the SSX plasma wind tunnel device. Initial experiments have been performed to characterize velocity, density, and magnetic field of relaxed helical Taylor states$^*$ formed in the glass boundary. We are also experimenting with resistive and mesh liners to provide some flux conservation of the Taylor states. Under construction is a theta pinch coil and pulsed power supply to accelerate the fully relaxed (tilted) Taylor states. Once characterization studies are complete, one or two prototype theta pinch coils will be used to accelerate the Taylor states to over $100~km/s$ and compressed to small volumes by stagnation. A segmented resistive or mesh flux conserver may also be employed. Preliminary un-accelerated characterizaton studies produce peak proton densities of $10^{15}~cm^{-3}$. Densities are measured with a precision quadrature He-Ne laser interferometer located in an expansion volume downstream of the glass extension. Temperatures will be measured by an ion Doppler spectrometer. Stagnated plasma parameters will be $n_e \approx 10^{16}~cm^{-3}$ with $T_i \ge 20~eV, B \ge 0.5~T$ with lifetimes over $100~\mu s$. Results from a single prototype acceleration coil will be presented. * Gray, et al, PRL {\bf 110}, 085002 (2013).