Radiation resistance of synthetic sapphire crystal irradiated by low-energy neutron flux

作者：Wang Gui Gen^*; Han Jie Cai; Zhang Hua Yu; Zhang Ming Fu; Zuo Hong Bo; Hu Zhao Hui; He Xiao Dong

来源：Crystal Research and Technology, 2009, 44(9): 995-1000.

DOI：10.1002/crat.200900243

• neutron radiation
• optical spectroscopy
• color center
• defect
• sapphire

In this paper, high-quality sapphire crystal grown by an improved Kyropoulos-like method, was irradiated by low-energy neutron (i.e. high proportion of thermal neutron) with various flux (low: 7.5x10(15) n/cm(2), medium: 7.0x10(16) n/cm(2) and high: 3.8x10(17) n/cm(2)). The characteristic features of neutron fluence dependence of radiation-defect formation process, mainly including its change of the structural and optical properties prior to and after irradiation, were investigated by optical absorption (OA), photoluminescence (PL), electron paramagnetic resonance (EPR) and positron annihilation spectroscopy (PAS). It is found that sapphire crystal exhibits high radiation resistance to low-energy neutron with low fluence. But with the increase of irradiation fluence, it is still sensitive to neutron irradiation mostly in the UV-visible spectral range, as irradiation-induced color centers appear, including F-type and their aggregate centers. Finally, the formation mechanism of the irradiation defects is also discussed.

• 单位
  harbin inst technol