Spatially resolved characterization of heavy ion irradiated LiF using static field gradient NMR

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 and the dynamical properties of the defects have been investigated temperature- and field-dependent. 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