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MM: Metall- und Materialphysik
MM 43: Diffusion III
MM 43.3: Talk
Friday, March 31, 2006, 13:00–13:15, IFW B
Radiation damage in fused quartz — •Poornnima Anbalagan1, Christine Negrini1, Andre Engelbertz1, Bernd Habenstein2, and Karl Maier1 — 1Helmholtz - Institut für Strahlen- und Kernphysik, Nußallee 14-16, 53115 Bonn — 2General Electric, Köln
Radiation damage has always been a topic of great interest in various fields of sciences. We have made an attempt to probe into the effect of subthreshold ultrasonic waves on the radiation damage created by irradiation of protons and alpha particles in the model system fused quartz. Three independent techniques were used to visualize the radiation damage. The polarization microscope shows the so-called Bragg-Peak, which is the region of maximum damage indicating internal stress in the sample. Positron annihilation spectroscopy was used to analyze the suppressed positronium generation due to the reduced positron diffusion as a result of radiation damage. UV-absorption spectroscopy shows a dominant absorption peak at an optical wavelength of 210nm. This corresponds to the E’-Centers and is an observable electronic defect. Surprisingly, the Bragg-Peak (which is identical with the particle range) is observable with the polarization microscope but not in the case of UV-absorption spectroscopy. A comparison between the samples that were irradiated and the samples that were exposed to ultrasonic waves simultaneously with irradiation shows the influence of the standing ultrasonic wave.