Density and Temperature Uniformity of a conical Section of a Spherically Imploding Plasma Liner

Abstract

Spherically imploding plasma liners 1 are a proposed reactorfriendly magneto-inertial-fusion (MIF) driver for compressing magnetized plasma targets to fusion conditions. The Plasma Liner Experiment–ALPHA (PLX-α) is aiming to demonstrate the formation of such liners via dozens of merging supersonic plasma jets (with ion density $\sim 10 ^{16}$ cm$^{-3}$, velocity $\approx 50$ km/s, mass $\sim 1$ mg, and various species). In the ongoing, first set of PLX-α experiments, we are merging 6 and 7 plasma jets to form a conical section of a spherically imploding plasma liner in order to assess the shock heating (and associated Mach-number degradation) and uniformity of the liner upon jet merging and during further convergence. Diagnostics include single- and multi-frame fast-gated ICCD cameras, visible survey spectrometer, high-resolution spectrometer, 12-chord visible interferometer, and visible photodiodes. Presented here will be the first results of the density and electron temperature uniformity of 6- and 7-jet merging using several gas species (argon, nitrogen, neon, krypton, xenon). Several 12-chord laser interferometry configurations are fielded with both end-on and crosssectional laser chord paths to determine density distribution and evolution. Results presented here will be compared to synthetic data from 3D simulations run using both smoothedparticle-hydrodynamics and the FronTier codes.