Thermoluminescence spectra of natural CaF2 irradiated by 10 MeV electrons

摘要

The spectra of thermoluminescence from natural and electron-irradiated fluorite in the 350-800nm spectral range were studied between room temperature and 500 degrees C. The sample came from Asturias (Spain) and was analyzed by X-ray diffractometry and inductively coupled plasma-mass spectrometry. Glow peaks appeared at 115, 205 and 310 degrees C. Main emissions occurred at 475, 575, 650 and 745nm, attributed to the Dy+3 ion and, at 410nm, from electron-hole recombination. The fractional glow technique and the general order model were employed to study the emission at 575 nm in detail. The results showed that the 115 and 205 degrees C glow peaks originate at traps with activation energies of 1.6 and 1.9 eV, respectively, on the kinetic order of 1.5 and 1.3 and frequency factors of 1.7 x 10(19) and 2.7 x 1019 s(-1), respectively. Spectrally resolved fading produced by storage was observed, and we concluded that the emission was due to large defect complexes. The dosimetric study showed that there was saturation at doses higher than 2 kGy. (c) 2005 Elsevier Ltd. All rights reserved.