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Title: Thermoluminescence mechanisms in lithium fluoride

Conference · · Natl. Bur. Stand. (U.S.), Spec. Publ.; (United States)
OSTI ID:7084298

Five glow peaks up to 200/sup 0/C are well known in lithium fluoride after gamma irradiation. Seven new glow peaks above 200/sup 0/C are reported in the present work. They are designated as I to XII in the ascending order of temperature of appearance. Activation energies are determined by initial rise method for five glow peaks, which could be well isolated by partial annealing from the lower temperature glow peaks. TL emission from the prominent glow peaks is similar and contains four bands with maxima at 370 nm, 390 nm, 415 nm, and 470 nm approximately. The spectral distribution of the total TL emission and emission from glow peaks V (195/sup 0/C) and XII (400/sup 0/C) are obtained also by plotting the integrated intensities of individual glow curves recorded at every 5 nm interval from 250 nm to 800 nm. The TL emission spectra obtained in this way are corrected for the instrument response. Optical absorption spectrum of lithium fluoride crystal is recorded after gamma irradiation. Distinct absorption bands are observed at 225 nm, 250 nm, 310 nm, and 380 nm. Absorption spectra are recorded also after various thermal annealing treatments. The spectral similarity of individual glow peaks and the continuous bleaching of F band (250 nm) with the annealing of individual peaks, shows that F centre takes part in recombination process at each stage of glow peak emission. The thermally released carrier at individual glow peaks is therefore of hole type.

Research Organization:
Bhabha Atomic Research Centre, Bombay
OSTI ID:
7084298
Journal Information:
Natl. Bur. Stand. (U.S.), Spec. Publ.; (United States), Vol. 461; Conference: International symposium on radiation physics, Calcutta, India, 30 Nov 1974; Other Information: See CONF-741109--
Country of Publication:
United States
Language:
English