Influence of the voltage-time derivative in X-ray emission from laboratory sparks

X-rays produced by laboratory sparks in air at atmospheric pressure for rod-rod and rod-plane configurations were observed. A total of 510 sparks were applied for both polarities. The paper shows the effects of the voltage rise time and the peak voltage in the generation of X-rays. It is found here that shorter rise times and high peak voltages tend to produce more X-rays emissions with higher energies than longer front waveforms or lower peak voltages. In a similar way, higher voltage variations produce more energetic emissions. This finding suggests that the variation of the electric field before the breakdown can play a fundamental role in the X-ray production. The results are similar with the observations of X-rays produced in natural lightning where detections have been associated to leader steps before the return stroke. Citation: March, V., and J. Montanya (2010), Influence of the voltage-time derivative in X-ray emission from laboratory sparks, Geophys. Res. Lett., 37, L19801, doi:10.1029/2010GL044543.