how to make Lichtenberg figures at home

http://www.sgsmp.ch/lichtenberg.htm

Acrylic is easy to get hold of - but a high energy electron beam? This is when being a medical physicist is definitely an advantage - at least if one is working in radiation therapy: we all use high energy electrons from a linear accelerator to treat patients, either directly, or to produce x-rays for treatment. If you are in this lucky situation, you should not rush to repeat our experiments, however: the dose rate available in clinical mode is insufficient to build up a sufficient charge within a short enough time; not all linear accelerators on the market are suitable for this exercise - and the suitable ones need to be modified. You must not try to repeat our experiments with a linac due to treat patients the next day - unless you have a large number of expensive spare parts sitting on your shelves.

Look at the effect of the light field mirror (left) and the monitor chamber (right) to know why. The effect on the electronics was less easy to document - but similarly impressive! The next time you decommission your Varian Clinac 2100 (I cannot comment on other manufacturers' linacs), however, this is your chance.

UNDER NO CIRCUMSTANCES SHOULD YOU REPEAT THE PROCEDURE DESCRIBED BELOW ON A LINEAR ACCELERATOR WHICH IS STILL IN CLINICAL USE !

---

Okay, no. This one is the at-home one, for those of you who have laser power supplies in your home. Please post pictures.