During the last few years, we have concentrated on developing
plasma radiation sources (PRS) for the longer current rise time
(up to 300 ns) of the direct-drive Decade Quad (DQ; Price et
al., 1999). In particular, we have developed an argon gas-puff
PRS that produces a high quality pinch with an ∼200-ns
implosion time, twice the implosion time of typical z
pinches. We have shown that large-diameter, solid-fill (i.e.,
the gas density is a smooth function of the radial distance
rather than a discrete shell) gas puffs can achieve adequate
heating and stability for long-implosion z pinches
with good K-shell yield.