The analysis of time-resolved optically stimulated luminescence: II. Computer simulations and experimental results

Abstract

This is the second in a set of paired papers on the analysis of time-resolved optically stimulated luminescence. This paper compares experimental results and computer simulations with corresponding conceptual models discussed in the first of this set of papers. The evaluation of principal and subsidiary luminescence lifetimes from time-resolved luminescence spectra measured during or after pulsed optical stimulation is illustrated using suitable analogues of exponential functions developed in the preceding paper. Various methods for calculating the activation energies for thermal quenching, thermal assistance and the frequency factor for the thermal quenching process using the temperature dependence of both luminescence lifetimes and luminescence intensity are described, as are techniques for dealing with cases not easily described by the standard Mott–Seitz model of luminescence. The paper then compares continuous and time-resolved optical stimulation methods, where it is shown that, dependent on suitable selection of the pulse-width, stimulation and measurement time, pulsing the stimulation light might give better accuracy in the determination of the luminescence.

Time-resolved optically stimulated luminescence and spectral emission features of α-Al2O3:C

“…[16,17,38] the parameter denotes the background. However, in -Al 2 O 3 :C, B is known to be a temperature-dependent phosphorescence component with a lifetime of several hundred milliseconds [23,25].…”

“…where T is the absolute temperature,  rad is the radiative lifetime at 0 K, ΔE is the activation energy for thermal quenching, k is Boltzmann's constant and the constant C is equal to  rad where  is the frequency factor for the non-radiative process [2,17]. The solid line through data in Fig.…”

The dependence of luminescence lifetimes on additive irradiation in natural sedimentary quartz: sands from Santa Elina, Brazil

“…The fitting is based on a model where for a material of stimulation probability λ, the luminescence counting rate L(t) during a brief rectangular pulse of width t 1 decreases in time as L(t) = κ exp (-(t -t 1 )/τ) where κ is a constant [3,6]. o C from a sample irradiated to 43 Gy.…”

“…The study of physical processes leading to emission of luminescence in quartz has been a major concern in luminescence research with the ultimate aim of improving techniques used in dosimetry. In particular, the investigation of dynamics of luminescence in quartz has taken a new impetus with the inception of investigations using time-resolved stimulation, a developing but viable alternative to established steady-state methods [2,3].…”

“…The study of time-resolved luminescence in quartz has concentrated on examples with known thermal and radiation histories [2,3]. The significant increase in intensity of luminescence that is observed following annealing made annealed samples the preferred choice over un-annealed and low sensitivity natural alternatives whose signals are less easy to interpret.…”