Speaker
Description
Using helium as a surrogate fill gas for deuterium in fusion experiments can be convenient to avoid flammability hazards in an experiment. To test the degree of equivalency between deuterium and helium, experiments were conducted in the Pecos target chamber at Sandia National Laboratories.
Observables such as laser propagation, energy deposition, and signatures of laser-plasma-instabilities (LPI) were recorded for multiple laser and target configurations. It was found (Fig. 1) that some observables can differ significantly despite the apparent similarity of the gases with respect to molecular charge and weight. A qualitative behavior of the interaction may very well be studied by finding a suitable compromise of laser absorption, electron density, and LPI cross-sections, but a quantitative investigation of expected values for deuterium fills may not succeed with surrogate gases.
Acknowledgements
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. DOE’s National Nuclear Security Administration under contract DE-NA0003525.
