Plasma diagnosis by dye laser intracavity absorption: Final report for period January 1, 1982-May 31, 1986

Dye laser intracavity absorption (ICA) has been studied as a potential diagnostic for plasma or neutral beam systems. For magnetic field measurements it is necessary to make Zeeman effect measurements on the resonance transition of atomic lithium on a millisecond time scale, or to make motional Stark Effect measurements on an injected fast atomic beam of hydrogen. To do this it may be necessary to sweep the dye laser in wavelength at a rapid rate so that the absorber can be sampled many times during the measurement. We have examined both of these possibilities during this contract. A rather detailed absorption spectrum of molecular hydrogen and deuterium arising in the 2c 3Piu and other electronic states has been obtained and analyzed. This has provided new information on the types of molecular species that may be detected in a plasma by ICA, and may provide a basis for the application of ICA for the diagnosis of the edge plasma in a tokamak or in the end regions of a mirror machine