Investigation of Ion Irradiation Effects in Silicon and Graphite Produced by 23 MeV I Beam

Both silicon and graphite are radiation hard materials with respect to swift heavy ions like fission fragments and cosmic rays. Recrystallisation is considered to be the main mechanism of prompt damage anneal in these two materials, resulting in negligible amounts of damage produced, even when exposed to high ion fluences. In this work we present evidence that these two materials could be susceptible to swift heavy ion irradiation effects even at low energies. In the case of silicon, ion channeling and electron microscopy measurements reveal significant recovery of pre-existing defects when exposed to a swift heavy ion beam. In the case of graphite, by using ion channeling, Raman spectroscopy and atomic force microscopy, we found that the surface of the material is more prone to irradiation damage than the bulk.

Materials analysis by ion channeling at "Demokritos"

A new fully automated Goniometer system installed recently at the Institute of Nuclear Physics of "Demokritos" is presented. This system enables to perform materials analysis not only via the Rutherford Backscattering method, which has been used so far at "Demokritos", but also by the ion channeling technique. The first experiments carried out using the Goniometer are also presented.