How Do Voltage and Time Influence Lichtenberg Figures in Acrylic?

[Pleiades]

If you aren't already aware, there are some folks who use a couple million volt particle accelerator to make lichtemberg figures in acrylic. If you watch some of their videos over at http://www.capturedlightning.com/frames/lichtenbergs.html#Make it looks like they only leave the acrylic under their high voltage particle beam for a few seconds. If you were to use a lower voltage accelerator, and were to leave the piece of acrylic under the beam for an extended period of time, would you be able to achieve similar results? Would you need to use smaller/thinner piece of acrylic?

 

[Baluncore]

For a fine point electrode applied to the centre of the top of a block, resting on a flat base electrode, there will be a minimum voltage below which the material will not break down. Once that minimum voltage is exceeded sufficiently the process will continue until a “feeler” reaches through the material and short circuits the voltage generator. The speed of the process is probably related to the available current from the high voltage source.