电子辐照BaF_2晶体的正电子寿命谱研究(英文)

Study of the positron lifetime on BaF_2 crystals irradiated with electrons

用不同能量和注量的电子辐照BaF2∶Sr晶体,分别测量了辐照前后的正电子寿命谱和吸收谱。为了与正电子寿命谱结果对比,也测量了相应的荧光谱。结果表明,在能量为1.5MeV和1.8MeV,注量为1.25×1015到2.57×1016e-cm-2mai的电子辐照情况下,在BaF2∶Sr晶体中主要产生F-H对,F色心和其它一些由杂质引起的色心;辐照温度对这些色心的形成和演化过程有较大的影响。

BaF2 ：physicsr crysta and chemistry. Is have been irradiated with electrons at different energies and doses. Their positron lifetimes and absorption spectra are measured and studied before and after electron irradiation. The fluorescence spectra are also measured and analyzed in order to validate the resuits from the positron lifetimes. The results show that the electron irradiation with energies of 1.5 and 1.8 MeV at the doses of 1.25 × 10^15 - to- 2.57 × 10^16 e^-cm^-2 mainly induces F-H pairs, F color centers and other color centers interfered by impurities in BaF2： Sr crystals. The study suggests that the irradiation temperature greatly influencs the forming and evolving processes of these color centers.