High-sensitivity interferometry measurements of initial density
distributions are reviewed for a wide range of gas-puff nozzles
used in plasma radiation source (PRS) z-pinch experiments.
Accurate gas distributions are required for determining
experimental load parameters, modeling implosion dynamics,
understanding the radiation properties of the stagnated pinch,
and for predicting PRS performance in future experiments. For
a number of these nozzles, a simple ballistic-gas-flow model
(BFM) has been used to provide good physics-based analytic fits
to the measured r, z density distributions.
These BFM fits provide a convenient means to smoothly interpolate
radial density distributions between discrete axial measurement
locations for finer-zoned two-dimensional MHD calculations, and
can be used to determine how changes in nozzle parameters and
load geometry might alter implosion dynamics and radiation
performance. These measurement and analysis techniques are
demonstrated for a nested-shell nozzle used in Double Eagle
and Saturn experiments. For this nozzle, the analysis suggests
load modifications that may increase the K-shell yield.
Measurement and analysis of gas-puff density distributions
for plasma radiation source z pinches