10.11578/1474167
Reymond, L
Diallo, A
Vekselman, V
Modeling of a Laser-Induced Rydberg Spectroscopy diagnostic for Direct Measurement of the Local Electric Field in the Edge Region of NSTX/NSTX-U
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
2018
en
Electric field
1474167
AC02-09CH11466
None
Specialized Mix
We discuss a novel diagnostic allowing direct measurements of the local electric field in the edge region in NSTX/NSTX-U. This laser based diagnostic's principle consists of depleting the naturally populated $n=3$ level to a Rydberg state --sensitive to electric fields-- that will result in a suppression of part of the $D_{\alpha}$ emission. We refer to this approach as Laser-Induced Rydberg Spectroscopy (LIRyS). It is shown that the local electric field can be measured through the Stark induced resonances observed as dips in the $D_\alpha$ emission. Using forward-modeling of simulated absorption spectra, we show precisions reaching \SI{\pm 2}{\kilo\volt\per\meter} in regions with a local electric field of \SI{15}{\kilo\volt\per\meter}.