Institut für Festkörperphysik, TU Darmstadt, Hochschulstraße 6, 64289 Darmstadt, Germany.
J Phys Condens Matter. 2010 May 12;22(18):185402. doi: 10.1088/0953-8984/22/18/185402. Epub 2010 Apr 15.
Spatially resolved (19)F and (7)Li spin-lattice relaxation rates are measured for LiF single crystals after irradiation with two kinds of swift heavy ions ((12)C of 133 MeV and (208)Pb of 1.78 GeV incident energy). Like in earlier studies on (130)Xe and (238)U irradiated LiF crystals, we found a strong enhancement of the nuclear spin-lattice relaxation rate within the ion penetration depth and a slight--but still significant--enhancement beyond. By evaluating the nuclear relaxation rate enhancement within the ion range after irradiation with different projectiles, a universal relationship between the spin-lattice relaxation rate and the dose is deduced. The results of accompanying X-band electron paramagnetic resonance relaxation measurements and optical absorption spectroscopy are included in a physical interpretation of this relationship. Also the reason for the enhanced relaxation rate beyond the ion range is further discussed.
我们测量了两种快重离子（入射能分别为 133 MeV 的 (12)C 和 1.78 GeV 的 (208)Pb）辐照后的 LiF 单晶体的（19）F 和（7）Li 核自旋晶格弛豫率。与之前对 (130)Xe 和 (238)U 辐照 LiF 晶体的研究一样，我们发现核自旋晶格弛豫率在离子穿透深度内有很强的增强，在穿透深度之外也有轻微但仍然显著的增强。通过评估不同射弹辐照后离子射程内的核弛豫率增强，可以得出自旋晶格弛豫率与剂量之间的普遍关系。该关系的物理解释还包括 X 波段电子顺磁共振弛豫测量和光吸收光谱的结果。此外，还进一步讨论了离子射程之外弛豫率增强的原因。
