Aluminum, calcium, and titanium imploding plasma experiments on the BLACKJACK 5 pulse generator

Abstract

The 10 TW BLACKJACK 5 pulse generator has been used to create both plasmas with electron densities on the order of 5×10²⁰ cm⁻³ and electron temperatures between 0.5 and 2 keV by imploding cylindrical arrays of fine aluminum, calcium, and titanium wires and ribbons. Visible streak photographs indicate that the wires are ionized by the prepulse and expand to ∼1‐mm diameter before imploding toward the central array axis to form a dense pinch. The individual plasmas assemble on axis at approximately peak current, at which time a 20–25‐ns FWHM pulse of K‐shell x‐ray radiation is emitted. Emission from H‐, He‐, and Li‐like ionization states has been observed with curved crystal spectrographs, and electron temperatures and densities have been inferred from these measurements. Pinhole photographs show intense emitting regions and kink structures in the plasma column.