Delocalized recombination kinetic modelling of the LiF : Mg,Ti glow peak 5 thermoluminescence system

Abstract

TL kinetic theory based on delocalized recombination mechanisms is successful in predicting many characteristics of TL mechanisms when these are considered singly. However, the greater challenge of predicting a set of measured TL characteristics while using the same, or very nearly the same, parameter values has yet to be adequately addressed. In this work we apply delocalized kinetic modelling to describe four experimentally measured characteristics of the TL behaviour of peak 5 in LiF : Mg,Ti (TLD-100). These include: (i) optical absorption linear/exponentially saturating dose response of the appropriate OA bands with the experimentally measured dose filling constants; (ii) linear/supralinear TL dose response with f(D)max = 4–6 at a dose level of ∼400–600 Gy; (iii) constancy of Tmax with dose; (iv) agreement with the experimentally measured behaviour of Tmax and f(D)max with heating rate. We are successful in describing most of the details of these characteristics; however, we have failed to find parameter values which also correctly describe the dose response behaviour at low dose levels (preceding the linear, then the supralinear region) and the behaviour of f(D)max with heating rate. It is suggested that kinetic modelling based on a mixture of localized and delocalized recombination could successfully describe all the characteristics involved.

Effect of capping agent concentration on thermoluminescence and photoluminescence of copper‐doped zinc sulfide nanoparticles

“…TL is directly related to the band structure of solids and particularly to the effects of impurities and lattice imperfections. These can be described as defect centres or just centres that may occur when ions of either side move away from their original sites, thus leaving vacant sites that are able to interact with free charge carriers .…”

Thermoluminescence characteristics of inorganically and organically capped ZnS:Cu nanophosphors

“…These can be described as defect centers or just centers that may occur when ions of either signs move away from their original sites, thus leaving vacant sites that are able to interact with free charge carriers. Various aspects of TL have been theoretically as well as experimentally studied to date [4][5][6][7]. TL has been demonstrated to be a trustworthy technique for dosimetry applications.…”

Ionization density effects following F-centre optical excitation in LiF : Mg, Ti (TLD-100): analysis via track structure theory

“…This glow peak is the major peak used in dosimetric applications and the temperature of maximum intensity, T max , appears at ∼205-210 • C when a linear heating rate of 1 • C s −1 is employed. The TL processes leading to composite glow peak 5 have been demonstrated to consist of both localized and delocalized recombination mechanisms [6,7] which give rise to a great many ionizationdensity-dependent phenomena [8].…”