K. Takaki et al., Simple and inexpensive interferometry of shock wave developments from pulsed high-current discharge, REV SCI INS, 71(3), 2000, pp. 1548-1551
Interferometer measurements are extremely informative in shock wave studies
allowing direct evaluations of the gas density. The primary goal of the wo
rk presented is to build a laser interferometer that meets the requirements
of the highest possible simplicity, economy, convenience, and ease of cons
truction. In our experiments, we used a low average power (10 mW) He-Ne las
er without complication, expense, and environmental section. The He-Ne lase
r interferometer with the Michelson arrangement was used to measure the lin
e-averaged gas densities of shock waves. Temporal and spatial measurements
of the density were performed for shock wave developments from high-current
pulse discharges. The shock wave propagates in the radial direction of the
discharge channel with supersonic speed. The shock velocity, however, decr
eased from 2-0.5 km/s with the distance of the shock propagation. The width
of the high density region, that is in the vicinity of the shock front was
compressed from 3.5 to 1.8 mm according to the time variation of the disch
arge current. (C) 2000 American Institute of Physics. [S0034-6748(00)00702-
4].