Femtosecond laser-induced breakdown spectroscopy in low-density gases relevant to pulsed power electrode desorption
ORAL
Abstract
Sandia National Laboratory’s Z Pulsed Power Facility radially compresses electrical energy in space and time to deliver a peak current of 30 MA and peak power of 80 TW to a mm-scale Z-pinch fusion load. The transmission line electrodes near the machine center are rapidly heated by the 100 ns current pulse and thermally desorb 1015 cm-3 gases comprising hydrogen, water, and various carbon-based contaminants. Field-emitted electrons dissociate and ionize these desorbed neutrals to form electrode gap plasmas that shunt MA-scale currents away from the fusion target. We report on our initial development of femtosecond laser-induced breakdown spectroscopy (fs-LIBS) to measure desorption from pulsed power electrodes. We achieved 1014 cm-3 detection capability and observed strong molecular signals in single-shot fs-LIBS measurements of gas cells containing H2, H2O, CH4, and CO2.
*This work was funded by Sandia National Laboratory's Laboratory Directed Research and Development Program. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government.
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Presenters
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Nathan P Brown
- Sandia National Laboratories