25 July 1989 Diagnostics In H2 Discharges Using A Tunable 193nm Excimer Laser
Author Affiliations +
An H- source for high brightness H° beams should have the lowest possible internal temperature T, because the beam-power density at a distance scales as 1/T. We determine local T inside a discharge with the use of a tunable ArF excimer laser that measures the populations of the lowest four rotational states of H2 by means of (2+1) resonance enhanced multiphoton ionization (REMPI). The number of laser-created ions causes a proportional change of the discharge's electrical impedance. A calibration in room temperature H2 (without a discharge) showed that the REMPI works well. Another objective is to develop a monitor for the vibrationally excited molecules, H2(v), that are believed to be the primary origin of H- within volume-type ion sources. We use the same apparatus and approach, but add a Raman shifter to change the laser wavelengths to those appropriate for (2+1) REMPI of H2(v).
© (1989) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Lynne M. Hitchcock, Gene P. Reck, Erhard W. Rothe, C. C. Tung, "Diagnostics In H2 Discharges Using A Tunable 193nm Excimer Laser", Proc. SPIE 1061, Microwave and Particle Beam Sources and Directed Energy Concepts, (25 July 1989); doi: 10.1117/12.951850; https://doi.org/10.1117/12.951850

Back to Top