A 1-kJ vacuum-spark device has been developed as a pulsed X-ray
source for applications in the field of microlithography, microscopy,
flash radiography, etc. The optimization works for the pulsed soft-X-ray
emission are presented. The optimization was made in two steps: 1) X-ray
emission maximization and 2) X-ray emission reproducibility. For the
X-ray emission maximization, the changed
... [Show full abstract] parameters were the main
capacitor energy, the anode-cathode geometry, the anode material, and
the trigger pulse amplitude. The best combination is 1 kJ for the main
capacitor energy, a conical shape for the anode, 6-12 mm anode-cathode
separation, iron for the anode material, and 14-15 kV for the trigger
pulse amplitude. In these conditions, energies of up to 10 J per pulse
are obtained in the 3-40 keV range for the X-ray pulses. In order to
have a good reproducibility, a high-power, very fast, high-voltage
trigger pulse is required. To fulfill these conditions, a pulse
transformer and an air spark gap were added to the initial triggering
device (a magnetic pulse compression circuit). With the new trigger
pulse (20 J per pulse, 50-ns rise-time, 22-kV amplitude in an open
circuit), an acceptable X-ray emission reproducibility was
obtained