Vacuum spark as a reproducible x-ray source

The operational characteristics of a laser-initiated vacuum spark is studied with reference to its x-ray emission. The present system employs a fast capacitor bank (current rise time=1 μs) with input energy of 4.4 kJ. The studies here show that for such a system, the system parameters can be adjusted for satisfactory optimum operation with respect to x-ray emission reproducibility. It is observed that intense x-ray point sources are obtained consistently by choosing the right V–d combination, where V is the discharge voltage in kilovolts and d is the electrode separation in millimeters. For the present system, this combination is found to be 20–5 and a x-ray reproducibility of better than 80% has been achieved in this system.