Multi-Beam Laser Interferometer for Plasma Density Measurements in a Plasma Density Measurements in a Plasma Erosion Opening Switch (PEOS)
Abstract
Science Research Laboratory has designed and fabricated a wide- bandwidth, highly sensitive, optical diagnostic for the simultaneous measurement of electron density and neutral gas density in plasma opening switches. The system uses two Mach-Zehnder interferometers, installed on a common support structure, to probe the refractive index of the plasma at 532 nm and 1064 nm along a common, 1-meter line-of-sight. Measurements at two wavelengths permit the effects of free electrons to be deconvolved from the effects of neutral gas species. The diagnostic is sensitive to fringe shifts of from 2xl0(exp-5) waves to 0.2 waves at bandwidths of up to 100 MHz. This allows the measurement of electron density path integrals from 5x 10(exp 12) sq cm to 5x 10(exp 16) sq cm with risetimes below 5 ns. The completed system was installed and tested on the HAWK facility at the Naval Research Laboratory in September 1993. Data is presented on the temporal history of the electron and neutral density path integrals in HAWK.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1994
- Accession Number
- ADA283209
Entities
People
- Stephen F. Fulghum