Comparison of POS-load dynamics using different plasma sources on Hawk

Hydrogen Plasma Opening Switch (POS) experiments on Hawk show potential for increasing bremsstrahlung radiation on DECADE. Interferometry indicates that the density of POS plasma is greatly reduced over a large fraction of the interelectrode region (>1 cm out of 2.2 cm) at the time of opening. This low-density region is much larger for the hydrogen POS than for flashover-source POSs used previously on Hawk (and DECADE), and may result in a significantly larger effective vacuum gap, improving the efficiency of energy coupling to loads. Species separation may be responsible for the difference in plasma dynamics between single- and multispecies POSs.