Development of an Interferometer Diagnostic for the Spheromak Turbulent Physics Experiment (STPX)

Jerry D. Clark, J. Titus, A. B. Alexander, E. D. Mezonlin

Research output: Contribution to journalArticlepeer-review

Abstract

Laser interferometry is a proven method for measuring electron density in fusion plasmas. Typically, far-infrared interferometers are used because of the large phase shift due to the change in the index of refraction of the plasma and their relative insensitivity to vibrations. A two-color (CO2: λ=10.6 μm, HeNe: λ=633 nm) interferometer has been designed for installation on STPX. The interferometer is a Mach-Zehnder configuration with a single-chord, double pass probe beam. The laser beams copropagate along a 10-meter path for vibration subtraction along with frequency modulation for heterodyne detection. Detection is carried out using a HgCdTe photoconductor for the CO2 and a Si APD for the HeNe. The capabilities and challenges with the installation of the interferometer on STPX will be discussed.
Original languageAmerican English
JournalAmerican Physical Society, 54th Annual Meeting of the APS Division of Plasma Physics
StatePublished - Oct 1 2012

Disciplines

  • Physical Sciences and Mathematics
  • Physics

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