Implosion Dynamics and Radiative Properties of Recent Experiments with W Double Planar Wire Arrays on UM Maize Ltd

The results of the 2017 experiments with tungsten (W) Double Planar Wire Arrays (DPWA) at the University of Michigan's (UM) low-impedance Linear Transformer Driver (LTD) MAIZE generator (
$(0.1 \Omega, 0.5-1 Ma$
, and 100–250 ns) are presented and analyzed. For these experiments, the peak of generator current was typically near 500 kA. Observations were made previously and tested for Al DPWAs on MAIZE
¹
. It was earlier determined that DPWA implosion dynamics depend strongly on the aspect ratio
$\phi,$
defined as array width to inter-planar gap, which ranged from 0.82 to 2.33, with array masses ranging from 55 to
$76 \mu \mathrm{g}/\text{cm}$
. New calculations were made to derive the time-dependent inductance throughout implosions on the MAIZE generator (using the formalism in ref.
²
), which were then used to calculate implosion characteristics and the dynamic plasma radius. This information can be used to better optimize future DPWA loads and measure the strength of the pinch. The diagnostics include an absolutely calibrated filtered photoconducting detector - PCD (>2.4 keV, time resolution 0.5 ns) and Si-diodes (> 1.4 ke V, time resolution > 1 ns), x -ray pinhole cameras, spectrometer, and 12-frame optical shadowgraphy system. The results are compared to those obtained earlier at the University of Nevada, Reno's (UNR) high-impedance Marx bank Zebra generator (
$1.9 \Omega, 1 \text{MA}, 100 \text{ns}$
).