Interferometry for measuring electron density distributions
After a brief summary of electromagnetic wave propagation in fully ionised plasmas and of the principles underlying electron density measurements by interferometry, the status and perspectives of multi-channel interferometers on present-day and future fusion devices are reviewed. Design criteria and hardware requirements (such as light sources, optical components and mechanical support structures) in relation to envisaged plasma parameters and diagnostic demands are outlined, and appropriate signal processing techniques are discussed. The latter include methods to control the gas injection and positional feedback systems and to provide real-time information on the electron density distribution during a discharge. Finally, the problem of reconstructing local electron densities from line-integrated phase shift measurements in the course of detailed retrospective profile analyses is addressed.
Bibliographic Reference: Article: Diagnostics for Contemporary Fusion Experiments (1991) pp. 75-94
Record Number: 199211078 / Last updated on: 1994-11-29
Original language: en
Available languages: en