Berlin 2008 – wissenschaftliches Programm
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ST: Fachverband Strahlen- und Medizinphysik
ST 4: Poster Session Radiation and Medical Physics
ST 4.1: Poster
Montag, 25. Februar 2008, 16:30–17:00, H 2033
Spatially resolved characterization of heavy ion irradiated LiF using static field gradient NMR — Holger Stork1, Annika Hamburger1,2, Kurt Schwartz3, Franz Fujara1, and •Achim Gädke1 — 1Technische Universität Darmstadt, Germany — 2Johann-Wolfgang-Goethe Universität, Frankfurt a. M., Germany — 3Gesellschaft für Schwerionenforschung, Darmstadt, Germany
Nuclear Magnetic Resonance (NMR) has been proven to be a valuable tool for investigating radiation damages in crystals. A relationship between the spin-lattice relaxation rate and the defect density has been derived and experimentally tested [1] and the dynamical properties of the defects have been investigated temperature- and field-dependent [2]. But up to now none of the NMR measurements was spatially resolved. This does not matter for homogeneously irradiated samples, but for heavy ions the defect creation is typically depth-dependent. In this contribution depth-dependent NMR relaxation measurements on heavy ion irradiated crystals are presented for the first time. The perturbation depth of the Xe and U ions we used in the LiF crystals was between 80 and 100 μm. In the irradiated area a clear increase of the relaxation rate could be observed. But we observed also a transition range outside the ion irradiated area where the relaxation rate is raised compared to the unirradiated sample. This effect might be due to secondary radiation. 1. phys.stat.sol. (b) 236, No. 1, 151-165 2.Rad. Eff. & Defects in Sol. Vol 155, 159-163