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Title: CO{sub 2} laser-based dispersion interferometer utilizing orientation-patterned gallium arsenide for plasma density measurements

A dispersion interferometer based on the second-harmonic generation of a carbon dioxide laser in orientation-patterned gallium arsenide has been developed for measuring electron density in plasmas. The interferometer includes two nonlinear optical crystals placed on opposite sides of the plasma. This instrument has been used to measure electron line densities in a pulsed radio-frequency generated argon plasma. A simple phase-extraction technique based on combining measurements from two successive pulses of the plasma has been used. The noise-equivalent line density was measured to be 1.7 × 10{sup 17} m{sup −2} in a detection bandwidth of 950 kHz. One of the orientation-patterned crystals produced 13 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 13 W of peak power. Two crystals arranged sequentially produced 58 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 37 W of peak power.
Authors:
; ;  [1] ; ;  [2] ; ; ;  [3]
  1. Physical Sciences Inc., 6652 Owens Drive, Pleasanton, California 94588 (United States)
  2. Physical Sciences Inc., 20 New England Business Center, Andover, Massachusetts 01810 (United States)
  3. General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)
Publication Date:
OSTI Identifier:
22220343
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 84; Journal Issue: 9; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ARGON; CARBON DIOXIDE LASERS; CRYSTALS; DISPERSIONS; ELECTRON DENSITY; ELECTRONS; GALLIUM ARSENIDES; HARMONIC GENERATION; INTERFEROMETERS; NONLINEAR PROBLEMS; PEAK LOAD; PLASMA DENSITY; PLASMA DIAGNOSTICS; RADIOWAVE RADIATION; TOKAMAK DEVICES