deep dielectric discharge (Lichtenberg figure)

This demonstration was performed by Keith Ryden of the University of Surrey, as part of the RADECS conference short course in Oxford, September 2013, in order to illustrate one of the main hazards of space weather for satellites -- i.e. ’deep dielectric discharge’. Photography was by Johan Ideström of OHB Bremen. • Radiation due to space weather can cause a gradual build-up of electrostatic charge in insulating (plastic) materials on spacecraft which can suddenly discharge causing upset and damage to on-board systems. • For the purposes of the demonstration a transparent material was used so that the audience could see the electrostatic discharge in progress - a mechanical shock was used to trigger it off. The resulting dramatic ’lightning storm’ goes on for some time! • The conduction pathways are vaporised leaving thin hollow tubes permanently remaining in the material in the form of a ’Lichtenberg’ fractal pattern. Date: 23rd September 2013 P