X-ray emission from copper X-pinches driven at a current rate of ∼1kA/ns

Abstract

A characterization of Cu X-pinches experiments driven at current rates ∼ 1kA/ns is presented. The emission of two bursts of X-rays associated with hot-spot formation and electron beam-target mechanism are identified. The first burst, associated with the central hot-spot, appears consistently at currents in the range (154 +/- 20) kA, with time correlated noticiable dips in the current derivative signal, which indicate sudden changes in load impedance. This first burst emits photons pulses of ∼ 1–2 ns width and with source sizes ranging between 50 and 150 μm with emission in the 2–5 keV energy range combined with photons in the ∼ 8–9 keV range. The second burst, associated with electron beam-target mechanism, emits longer pulses of tens of nanoseconds, with source sizes larger than ∼ 0.75 mm and emission concentrated in energies>5 keV, reaching up to 9 keV or more. Spectroscopic data shows the presence of K-shell line emissions of Cu XXVII and Cu XXVIII, which combined with PrismSpect simulations indicate a electron temperature of ∼ 850 eV with an ion density of 1022 cm−3. Further details and analysis of the X-pinch plasma and its possible applications are presented and discussed.