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Plasma Physics Reports

, Volume 28, Issue 10, pp 806–813 | Cite as

Pulsed time-of-flight refractometry measurements of the electron density in the T-11M tokamak

  • A. A. Petrov
  • V. G. Petrov
  • A. Yu. Malyshev
  • V. K. Markov
  • A. V. Babarykin
Tokamaks

Abstract

A new method for measuring the plasma density in magnetic confinement systems—pulsed time-of-flight refractometry—is developed and tested experimentally in the T-11M tokamak. The method is based on the measurements of the time delay of short (with a duration of several nanoseconds) microwave pulses propagating through the plasma. When the probing frequency is much higher than the plasma frequency, the measured delay in the propagation time is proportional to the line-averaged electron density regardless of the density profile. A key problem in such measurements is the short time delay of the pulse in the plasma (∼1 ns or less for small devices) and, consequently, low accuracy of the measurements of the average density. Various methods for improving the accuracy of such measurements are proposed and implemented in the T-11M experiments. The measurements of the line-averaged density in the T-11M tokamak in the low-density plasma regime are performed. The results obtained agree satisfactorily with interferometric data. The measurement errors are analyzed, and the possibility of using this technique to measure the electron density profile and the position of the plasma column is discussed.

Keywords

Microwave Time Delay Plasma Density Density Profile Plasma Frequency 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© MAIK "Nauka/Interperiodica" 2002

Authors and Affiliations

  • A. A. Petrov
    • 1
  • V. G. Petrov
    • 1
  • A. Yu. Malyshev
    • 1
  • V. K. Markov
    • 1
  • A. V. Babarykin
    • 1
  1. 1.Troitsk Institute for Innovation and Fusion ResearchTroitsk, Moscow oblastRussia

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