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Plasma density gradient measurement using laser deflection.
- Source :
- Review of Scientific Instruments; Jun2005, Vol. 76 Issue 6, p063503, 7p
- Publication Year :
- 2005
-
Abstract
- For a given chord through a plasma, changes in the line integrated index of refraction as a result of a transverse density gradient can be observed by measuring the angle of deflection of a laser beam. In contrast to laser interferometers, this method of density profile measurement places modest requirements on laser quality and alignment procedures, allowing measurements to be conducted with short coherence length commercial laser diodes and segmented photodiode detectors. A prototype implementation of this scheme has been constructed and tested on the compact toroid injection experiment (CTIX). At densities comparable to magnetic fusion plasmas, laser deflections in the nanoradian range were measured. By assuming a particular density profile, a sensitivity of ∼10<superscript>12</superscript> cm<superscript>-3</superscript>/nrad was obtained. This produced estimates of CTIX peak density in reasonable agreement with conventional interferometry data. The final goal of this diagnostic is a simple, reliable, array deployable density profile diagnostic. [ABSTRACT FROM AUTHOR]
- Subjects :
- LASER beams
PLASMA gases
PHOTODIODES
DETECTORS
LASER interferometers
INTERFEROMETRY
Subjects
Details
- Language :
- English
- ISSN :
- 00346748
- Volume :
- 76
- Issue :
- 6
- Database :
- Complementary Index
- Journal :
- Review of Scientific Instruments
- Publication Type :
- Academic Journal
- Accession number :
- 17392191
- Full Text :
- https://doi.org/10.1063/1.1935447