Characterization of wire x pinches driven by a microsecond-long capacitive discharge

The use of a simple capacitive discharge as a driver for an x-pinch soft x-ray source is demonstrated. The 30 kV, 4 kJ capacitive discharge had a quarter period of 1.2 μs, peak current of 320 kA, and current rise of 2.5×1011 A s−1. X-pinch x-ray emission was characterized by pinhole photography and solid-state detectors. Soft x-ray emission (800 eV–4 keV) was observed in both single and multiple bursts, with yields from 180 mJ for aluminum to 1.5 J for tungsten wire x pinches. X-ray emission from x pinches was higher than z-pinch emission from the same materials using the same power source. Hard x-ray emission (>8 eV) from the x pinch was lower with the long pulse capacitive discharge than with a 360 kV pulsed power driver delivering 100 kA peak with a rate of current rise of 2.2×1012 A s−1. Visible photography and laser-based schlieren photography showed that the x pinch was asymmetric about the crossing point of the wires. This asymmetry is due to the influence of electron beam generation at this point.