Efficient argon <i>K</i>-shell radiation from a Z pinch at currents &amp;gt;15 MA

Abstract

The first observations of gaseous load implosions with over 15 MA in &amp;gt;110 ns on the Z generator [R. B. Spielman et al., Phys. Plasmas 5, 2105 (1998)] are reported. Starting from a diameter of over 8 cm, an argon double-shell Z pinch imploded to under 0.5 cm K-shell emission diameter. With a load mass of 0.8 mg/cm, K-shell x-ray output reached 274±24 kJ in a 15 TW peak power, 12 ns pulse. This record-high yield is consistent with the current-squared scaling predicted for the “efficient” emission regime.