Two-Photon Absorption Laser-Induced Fluorescence measurements of atomic hydrogen and deuterium density in RAID*

RAID is a linear basic plasma experiment located at the Swiss Plasma Center in Lausanne, Switzerland. Due to its ability to produce steady-state plasmas with conditions relevant to the divertor and scrape-off layer of tokamaks, as well as its wide range of diagnostics, RAID is well-suited to the experimental study of fundamental atomic and molecular processes and can serve as a testbed for the validation of edge modeling codes such as the SOLPS-ITER code package. We report on the first 1D-resolved measurements of atomic hydrogen and deuterium density using a recently installed Two-Photon Absorption Laser-Induced Fluorescence diagnostic. The experimental apparatus comprises a ps laser system allowing the accurate measurement of the fluorescence decay time as well as an ICCD camera capable of simultaneous measurements of 1D density profiles with 1 mm spatial resolution.