Open Access1 μs broadband frequency sweeping reflectometry for plasma density and fluctuation profile measurements
Author(s) -
F. Clairet,
C. Bottereau,
A. Medvedeva,
D. Molina,
G. D. Conway,
A. Silva,
U. Stroth
Publication year - 2017
Publication title -
review of scientific instruments
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.605
H-Index - 165
eISSN - 1089-7623
pISSN - 0034-6748
DOI - 10.1063/1.4991789
Subject(s) - reflectometry , asdex upgrade , plasma , voltage , plasma diagnostics , upgrade , electron density , linearity , optics , materials science , broadband , physics , computer science , tokamak , time domain , quantum mechanics , computer vision , operating system
Frequency swept reflectometry has reached the symbolic value of 1 μs sweeping time; this performance has been made possible, thanks to an improved control of the ramp voltage driving the frequency source. In parallel, the memory depth of the acquisition system has been upgraded and can provide up to 200 000 signals during a plasma discharge. Additional improvements regarding the trigger delay determination of the acquisition and the voltage ramp linearity required by this ultra-fast technique have been set. While this diagnostic is traditionally dedicated to the plasma electron density profile measurement, such a fast sweeping rate can provide the study of fast plasma events and turbulence with unprecedented time and radial resolution from the edge to the core. Experimental results obtained on ASDEX Upgrade plasmas are presented to demonstrate the performances of the diagnostic.
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