Characterization of a small railgun-based plasma jet source

Experimental characterization of a small plasma jet source has been undertaken at Virginia Tech's Center for Space Science and Engineering Research (Space@VT). The plasma-armature railgun features a square bore approximately $0.5 \times 0.5$~cm and a rail length of $\approx 10$~cm. Fed by an $\approx 100$~psi- gas manifold and powered by an LC pulse-forming network capable of delivering $\approx 100$~kA current on timescales of several microseconds, jet velocities in the 10-20~km/s range are predicted. A modular design, the insulators and rails are readily swappable for investigation the interaction of the plasma armature with plasma-facing components fabricated with different materials and geometry. The plasma jet is characterized by a suite of diagnostics including a multichord Mach-Zehnder interferometer, spectrometer, photodiode array, and fast photography. Diagnostics planned for the near future include plasma laser-induced fluorescence and particle energy analyzers. The railgun source described is envisioned as a future platform for basic science experiments on topics ranging from plasma-material interaction to plasma shocks.