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Title: CO{sub 2} ({lambda}{sub m}=10.6 {mu}m) He-Ne ({lambda}{sub c}=633 nm) two-color laser interferometry for low and medium electron density measurements in the TJ-II Stellarator

Abstract

In this article we describe the setup, installation, calibration, and operation of the two-color (CO{sub 2}-HeNe) laser heterodyne interferometer installed in the TJ-II Stellarator. This diagnostic has been routinely working during the last TJ-II experimental campaign (Autumn 2003) in low-density [electron cyclotron resonance (ECRH) heated, n{sub e} congruent with 10{sup 19} m{sup -3}] and medium density [neutral beam injection (NBI) heated, n{sub e} congruent with 5x10{sup 19} m{sup -3}] plasmas with line integral error better than 2x10{sup 17} m{sup -2}. This work demonstrates the possibility of using low-cost two wavelength laser interferometric diagnostics to measure low and medium-density plasmas instead of the complicated far infrared (FIR) interferometric systems that also suffer from fringe-jumps errors. The issues of low sensitivity to plasma density and mechanical vibration subtraction typical of these laser interferometers are solved through proper calibration of the interferometric system in the machine. First results on NBI heated plasmas measured by the laser interferometric system in the Stellarator TJ-II will be shown.

Authors:
; ; ; ;  [1]
  1. Departamento de Tecnologia Electronica. Universidad Carlos III de Madrid, Avda. de la Universidad 30, Leganes 28911 Madrid (Spain)
Publication Date:
OSTI Identifier:
20644005
Resource Type:
Journal Article
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 75; Journal Issue: 11; Other Information: DOI: 10.1063/1.1809283; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0034-6748
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BEAM INJECTION HEATING; CALIBRATION; CARBON DIOXIDE LASERS; CYCLOTRON RESONANCE; ECR HEATING; ELECTRON DENSITY; HELIUM-NEON LASERS; INTERFEROMETERS; INTERFEROMETRY; PLASMA BEAM INJECTION; PLASMA CONFINEMENT; PLASMA DENSITY; PLASMA DIAGNOSTICS; RF SYSTEMS; STELLARATORS; THERMONUCLEAR REACTORS

Citation Formats

Acedo, Pablo, Lamela, Horacio, Sanchez, Miguel, Estrada, Teresa, Sanchez, Joaquin, and Asociacion EURATOM/CIEMAT, Ciudad Universitaria s/n. 28040 Madrid. CO{sub 2} ({lambda}{sub m}=10.6 {mu}m) He-Ne ({lambda}{sub c}=633 nm) two-color laser interferometry for low and medium electron density measurements in the TJ-II Stellarator. United States: N. p., 2004. Web. doi:10.1063/1.1809283.
Acedo, Pablo, Lamela, Horacio, Sanchez, Miguel, Estrada, Teresa, Sanchez, Joaquin, & Asociacion EURATOM/CIEMAT, Ciudad Universitaria s/n. 28040 Madrid. CO{sub 2} ({lambda}{sub m}=10.6 {mu}m) He-Ne ({lambda}{sub c}=633 nm) two-color laser interferometry for low and medium electron density measurements in the TJ-II Stellarator. United States. https://doi.org/10.1063/1.1809283
Acedo, Pablo, Lamela, Horacio, Sanchez, Miguel, Estrada, Teresa, Sanchez, Joaquin, and Asociacion EURATOM/CIEMAT, Ciudad Universitaria s/n. 28040 Madrid. 2004. "CO{sub 2} ({lambda}{sub m}=10.6 {mu}m) He-Ne ({lambda}{sub c}=633 nm) two-color laser interferometry for low and medium electron density measurements in the TJ-II Stellarator". United States. https://doi.org/10.1063/1.1809283.
@article{osti_20644005,
title = {CO{sub 2} ({lambda}{sub m}=10.6 {mu}m) He-Ne ({lambda}{sub c}=633 nm) two-color laser interferometry for low and medium electron density measurements in the TJ-II Stellarator},
author = {Acedo, Pablo and Lamela, Horacio and Sanchez, Miguel and Estrada, Teresa and Sanchez, Joaquin and Asociacion EURATOM/CIEMAT, Ciudad Universitaria s/n. 28040 Madrid},
abstractNote = {In this article we describe the setup, installation, calibration, and operation of the two-color (CO{sub 2}-HeNe) laser heterodyne interferometer installed in the TJ-II Stellarator. This diagnostic has been routinely working during the last TJ-II experimental campaign (Autumn 2003) in low-density [electron cyclotron resonance (ECRH) heated, n{sub e} congruent with 10{sup 19} m{sup -3}] and medium density [neutral beam injection (NBI) heated, n{sub e} congruent with 5x10{sup 19} m{sup -3}] plasmas with line integral error better than 2x10{sup 17} m{sup -2}. This work demonstrates the possibility of using low-cost two wavelength laser interferometric diagnostics to measure low and medium-density plasmas instead of the complicated far infrared (FIR) interferometric systems that also suffer from fringe-jumps errors. The issues of low sensitivity to plasma density and mechanical vibration subtraction typical of these laser interferometers are solved through proper calibration of the interferometric system in the machine. First results on NBI heated plasmas measured by the laser interferometric system in the Stellarator TJ-II will be shown.},
doi = {10.1063/1.1809283},
url = {https://www.osti.gov/biblio/20644005}, journal = {Review of Scientific Instruments},
issn = {0034-6748},
number = 11,
volume = 75,
place = {United States},
year = {2004},
month = {11}
}