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A survey of reflectometry techniques with applications to TFTR

Technical Report ·
DOI:https://doi.org/10.2172/10144282· OSTI ID:10144282
;  [1]; ; ; ;  [2];  [3]
  1. Georgia Inst. of Tech., Atlanta, GA (United States)
  2. Oak Ridge National Lab., TN (United States)
  3. Princeton Univ., NJ (United States). Plasma Physics Lab.

This report presents a review of reflectometry with particular attention to eXtraordinary mode (X-mode) reflectometry using the novel technique of dual frequency differential phase. The advantage of using an X-mode wave is that it can probe the edge of the plasma with much higher resolution and using a much smaller frequency range than with the Ordinary mode (O-Mode). The general problem with previous full phase reflectometry techniques is that of keeping track of the phase (on the order of 1000 fringes) as the frequency is swept over the band. The dual frequency phase difference technique has the advantage that since it is keeping track of the phase difference of two frequencies with a constant frequency separation, the fringe counting is on the order of only 3 to 5 fringes. This fringe count, combined with the high resolution of the X-mode wave and the small plasma access requirements of reflectometry, make X-mode reflectometry a very attractive diagnostic for today`s experiments and future fusion devices.

Research Organization:
Georgia Inst. of Tech., Atlanta, GA (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC05-84OR21400
OSTI ID:
10144282
Report Number(s):
GTFR--112; ON: DE94010202
Country of Publication:
United States
Language:
English