Dye laser fluorescence spectroscopy on the Doublet III tokamak

Measurements of edge-region TiI impurity densities and central-region deuterium (n=2) densities have been obtained in the Doublet III tokamak using laser induced fluorescence spectroscopy. TiI densities range from 1012 to 1013 m-3 in ohmically heated D2 discharges and a factor of 2 to 5 times less in H2 discharges. Edge region TiI equilibration times following neutral-beam injection are in good agreement with central region ion confinement times suggesting that energetic charge-exchange neutrals from the plasma center are responsible for TiI impurities. Resonance fluorescence scattering from deuterium atoms in the plasma center has been observed using a broadband (8 nm) dye laser source and a narrow band detector to investigate the feasibility of determining ion temperatures