Multi-chord fiber-coupled interferometry of supersonic plasma jets (invited)

A multi-chord fiber-coupled interferometer is being used to make time-resolved density measurements of supersonic argon plasma jets on the Plasma Liner Experiment. The long coherence length of the laser (>10 m) allows signal and reference path lengths to be mismatched by many meters without signa...

Full description

Saved in:
Bibliographic Details
Published in:Review of scientific instruments 2012-10, Vol.83 (10), p.10D523-10D523
Main Authors: Merritt, Elizabeth C, Lynn, Alan G, Gilmore, Mark A, Thoma, Carsten, Loverich, John, Hsu, Scott C
Format: Article
Language:English
Subjects:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Argon plasma
ATOMS
COHERENCE LENGTH
DENSITY
EXPANSION
INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
INTERFEROMETERS
INTERFEROMETRY
IONIZATION
METERS
NUMERICAL ANALYSIS
PHASE SHIFT
PLASMA
PLASMA JETS
REFRACTIVE INDEX
SIMULATION
SUPERSONIC FLOW
Three dimensional
TIME RESOLUTION
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A multi-chord fiber-coupled interferometer is being used to make time-resolved density measurements of supersonic argon plasma jets on the Plasma Liner Experiment. The long coherence length of the laser (>10 m) allows signal and reference path lengths to be mismatched by many meters without signal degradation, making for a greatly simplified optical layout. Measured interferometry phase shifts are consistent with a partially ionized plasma in which both positive and negative phase shift values are observed depending on the ionization fraction. In this case, both free electrons and bound electrons in ions and neutral atoms contribute to the index of refraction. This paper illustrates how the interferometry data, aided by numerical modeling, are used to derive total jet density, jet propagation velocity (~15-50 km/s), jet length (~20-100 cm), and 3D expansion.
ISSN:0034-6748
1089-7623
DOI:10.1063/1.4734496