Fast pressure probe measurements of a high-velocity plasma plume

Abstract

This article reports measurements of stagnation pressure on a contoured coaxial gun, now installed at the Maryland Centrifugal Experiment [R. Ellis et al., Phys. Plasmas 12, 055704 (2005)]. The impact of the plasma on the stationary probe is consistent with adiabatic compression and supersonic flow. Measured pressure signals are consistent with a shock traveling at 110 km/s and a following flow with speed of 90 km/s. At late times, the pressure profile is consistent with an adiabatically expanding plasma that fills the vacuum chamber.

Experimental characterization of railgun-driven supersonic plasma jets motivated by high energy density physics applications

“…The development, optimization, and performance scaling results of these PLX railguns, as well as the simultaneous experimental achievement of the aforementioned jet parameters, will be reported elsewhere. Note that larger coaxial guns with shaped electrodes [31][32][33] are also being developed due to their suitability for very high current (> 1 MA) and high jet velocity (> 100 km/s) operation, and for having attributes that minimize impurities, as potentially required for the MIF application.…”

Interferometer density measurements of a high-velocity plasmoid

“…The sharp rise near 15 s corresponds to the arrival of the plasma at the location of the interferometer observation volume, as verified by high speed photography and fast pressure probe measurements. 12 Following the sharp rise there is a period of slow variation, followed by a gentle fall back toward zero density. The feature appearing at approximately 55 s is a second plasmoid ejected from the gun due to ringing of the capacitor bank, as shown in Fig.…”