Thermoluminescence Peak Research Articles

Radiophotoluminescence and thermoluminescence characteristics of undoped and Mg doped LiF phosphor in the high dose region

Radiophotoluminescence (RPL) and thermoluminescence (TL) from undoped and Mg-doped LiF powder samples were investigated for high dose dosimetric applications. F-aggregate centres in LiF are created by radiolysis. The RPL emission at 530 nm and 650 nm from F3+ and F2 centres respectively (on excitation at 450 nm) in undoped commercial LiF powder enhanced with increasing sintering temperature. Its TL glow curve showed peaks at 145, 290 and 365 °C. The RPL-TL correlation studies carried out for the first time showed that the thermal annihilation of F3+ and F2 centes following Fi0 - Va (interstitial-vacancy) recombination cause 290 °C and 365° TL peaks respectively. This showed that F2 centres are thermally more stable than F3+ centres. Its integrated TL response kept increasing nearly linearly up to 14 kGy, in contrast to the response of the TL peaks in dosimetry grade LiF:Mg, Ti (TLD-100). However, the TL from LiF suffers from fading problems. A 100 °C, 15 min pre-read annealing treatment erased most of the 145 °C TL peak without disturbing the other high temperature peaks. A 750° C, 22 h sintering treatment in carbon atmosphere shifted the major TL glow peak of undoped LiF to 200 °C but reduced its TL sensitivity by more than a factor of 10. Mg-doped LiF samples exhibit a TL glow curve peaking at ∼240 °C with satellite peaks typical of Mg doped LiF whose shape did not change significantly with gamma dose. However it showed lower TL and RPL sensitivities as compared to those of undoped LiF. All LiF except LiF alfa (750 °C, 1 h, CB) showed sublinear increase in TL with dose and therefore will cause inaccuracy in dose measurements especially at high doses due to reduced sensitivity. LiF alfa 750 °C, 22 h and 1000 °C, 6 min sintered powder samples are better than others because their RPL sensitivity increases nearly linearly with dose. However, a low fading observed in the latter sample supports its application. The bright yellow RPL emission seen through a 550 nm cut on filter illuminated with a 450 nm blue LED or He-Cd laser light could quickly confirm an irradiated consignment on which LiF samples are affixed. The increase in green to red emission ratio with dose and post-irradiation storage period might be related to slow migration of anion vacancies created by one secondary electron track to F centres created by another track and consequent conversion of F2 → F3+ centres.

Photoluminescence and Thermoluminescence Properties of Sol-Gel Auto-Combustion Driven Mg2SnO4 Nanophosphor

Nanocrystalline Mg2SnO4 nanophosphor was synthesized by a facile sol-gel auto-combustion method calcined 800°C for 1 h. The X-ray diffraction pattern showed that the nanopowder has a cubic inverse spinel polycrystalline structure with an average crystallite size of about 20 nm. The photoluminescence spectra were measured at 84−300 K, and the broad emission band was obtained in the wavelength range of 400−500 nm. Photoluminescence at 120 K showed the highest emission band centered around 414 nm. The thermoluminescence (TL) glow curve showed an increase in TL peak intensity with UV irradiation time due to the increasing number of inherent traps created by UV irradiation. The maximum TL intensity was found for 30 min UV exposure. Activation energies of the trapping centers were found between 0.39 eV and 0.48 eV. The frequency factor of the main glow-peak was also evaluated in the 3.03 × 106–4.26 × 107 s−1 range for UV irradiated phosphor. The decrease in activation energy and frequency factor with increasing UV exposure time may attribute to the decrease in trap depth. The calculated trap parameters related to the glow peak show this phosphor may be useful in radiation dosimetry applications.

Development of a new rare-earth (Dy3+)-based thermoluminescent dosimeter

In this work, two tissue equivalent dosimeters i.e. LiF: Mg, Ti and LiF: Mg, Dy with the same concentration of Mg were synthesized by a chemical co-precipitation method. The crystallite size determined using Sherrer's formula ranged from 30nm to 35nm. The absorbance spectra revealed the presence of stretching vibrations of oxides of titanium and dysprosium in LiF: Mg, Ti, and LiF: Mg, Dy, in which oxygen was attached with Ti4+ and Dy3+ cations, respectively. LiF: Mg, Ti exhibited 5 thermoluminescent (TL) peaks corresponding to the multi-trap multi-recombination module with trap depths ranging from 2.052 to 2.89eV. In LiF: Mg, Dy, only one TL peak was observed corresponding to one-trap and one-recombination module with a trap depth ranging from 2.0318 to 2.5489eV. The dosimetric peaks of LiF: Mg, Ti occurred in the temperature range 240–260°C (peak 4) and 280–290°C (peak 5) with a maximum fading of 2.7% in 108h. The single dosimetric peak of LiF: Mg, Dy occurred in the temperature range l20–220°C with a maximum fading of 4.9% for the same duration. The minimum detected dose in LiF: Mg, Ti was 10mSv with a calibration factor of 0.08882, while in LiF: Mg, Dy, the minimum detected dose was 40mSv with a calibration factor of 0.34129. Ti-based dosimeter was found to have a linear response in the range of 10 – 10,000mSv, while, Dy-based dosimeter responded linearly in the dose range of 40 – 10,000mSv. The latter dosimeter was found to be 3 time less sensitive than the former; therefore, for personal and extremity dosimetry, the former dosimeter appeared more suitable; while for high doses, the latter dosimeter responded well.

Assessment of microbiological contamination in saengshik products from the Korean market and identification of the irradiation status.

This study investigated the prevalence of microbiological contamination in commercial Saengshik products (samples SP-1 to SP-12) from the Korean market, and identified their irradiation status. SP-2, SP-8, and SP-12 showed less than 3.66 and 1.10 log colony forming units (CFU)/g in total plate and coliforms counts, respectively, while the remaining samples showed more than 4.70 and 2.35 log CFU/g, respectively. Four samples were positive on some of foodborne pathogenic bacteria (Clostridium perfringens,Escherichia coli O157:H7, andBacillus cereus). SP-2, SP-8, and SP-12 contained no pathogenic bacteria and were suspected to have been irradiated. They were confirmed as positive using photostimulated luminescence (PSL) analysis. PSL positive results on samples SP-2, SP-8 and SP-12 were finally confirmed by the authentic thermoluminescence (TL) analysis on the basis of TL glow curve shape, intensity, temperature range of TL peak maxima and TL ratio (TL1/TL2).

Trap distribution in AgIn5S8 single crystals: Thermoluminescence study

Distribution of shallow trap levels in AgIn5S8 crystals has been investigated by thermoluminescence (TL) measurements performed below room temperature (10–300 K). One broad TL peak centered at 33 K was observed as constant heating rate of 0.2 K/s was employed for measurement. The peak shape analysis showed that the TL curve could consist of several individual overlapping TL peaks or existence of quasi-continuous distributed traps. Therefore, TL experiments were repeated for different stopping temperatures (Tstop) between 10 and 34 K with constant heating rate of 0.2 K/s to separate the overlapping TL peaks. The Et vs Tstop indicated that crystal has quasi-continuously distributed traps having activation energies increasing from 13 to 41 meV. Heating rate effect on trapped charge carriers was also investigated by carrying out the TL experiments with various heating rates between 0.2 and 0.6 K/s for better comprehension of characteristics of existed trap levels. Analyses indicated that the trap levels exhibited the properties of anomalous heating rate behavior which means the TL intensity and area under the TL peak increase with increasing heating rate.

A micro-structural distortion mechanism on the thermal degradation of Y3Al5O12:Ce3+ phosphor

The thermal degradation is one of the key problems that restricting the working properties and lifetime of Y3Al5O12:Ce3+ phosphor for white light-emitting diode (LED) application. To clarify its thermal degradation mechanism, a heat-treatment process was carried out, and the effects of heat-treatment temperature on the luminescent intensity and micro-structure changes were investigated. Based on the evidences about micro-structural distortion detected by XRD, IR, TL and XPS, the relationship between luminescent intensity and micro-structure change was founded, and a micro-structural distortion mechanism on the thermal degradation was proposed. The emission intensity decreased with the increasing heat-treatment temperature, which was an accelerated thermal degradation. The intensities of two thermoluminescence peaks at 112 °C and 248 °C also decreased with the increasing heat-treatment temperature and towards zero. This indicated that the corresponding defects levels were gradually eliminated and a micro-structural distortion occurred. X-ray photoelectric spectroscopy results showed small part of trivalent cerium ions were oxidized to tetravalent cerium ions, and alumina tetrahedral were gradually transformed into alumina octahedron. Therefore, the thermal degradation was jointly caused by the oxidation of Ce3+ and the distortion of micro-structure.

Copper-doped lithium triborate (LiB3O5) crystals: A photoluminescence, thermoluminescence, and electron paramagnetic resonance study

When doped with copper ions, lithium borate materials are candidates for use in radiation dosimeters. Copper-doped lithium tetraborate (Li2B4O7) crystals have been widely studied, but little is known thus far about copper ions in lithium triborate (LiB3O5) crystals. In the present investigation, Cu+ ions (3d10) were diffused into an undoped LiB3O5 crystal at high temperature. These ions occupy both Li+ and interstitial positions in the crystal. A photoluminescence (PL) band peaking near 387nm and a photoluminescence excitation (PLE) band peaking near 273nm verify that a portion of these Cu+ ions are located at regular Li+ sites. After an irradiation at room temperature with x rays, electron paramagnetic resonance (EPR) spectra show that Cu+ ions at Li+ sites have trapped a hole and converted to Cu2+ ions (3d9) while Cu+ ions at interstitial sites have trapped an electron and converted to Cu0 atoms (3d104s1). Two distinct Cu2+ trapped-hole spectra are formed by the x rays: one due to isolated Cu2+ ions with no nearby defects and the other due to perturbed Cu2+ ions. When the x-ray-irradiated crystal is heated above room temperature, a thermoluminescence (TL) peak appears at 120°C with a maximum in the emitted light near 630nm. EPR shows that this TL peak occurs when trapped electrons are thermally released from interstitial Cu0 atoms. Thermal quenching above room temperature prevents the electron-hole recombination at Cu2+ ions from contributing to the TL emission.

Parametric study of plasma-mediated thermoluminescence produced by Al2O3 sub-micron powders

Sub-micron Al2O3 powders with a surface activated by dielectric barrier discharge exhibit improved performance in wet deposition of ceramic layers. In addressing the possible mechanisms responsible for the observed improvement, a comprehensive thermoluminescence (TL) study of plasma-activated powders was performed. TL offers the unique possibility of exploring the population of intrinsic electrons/holes in the charge trapping states. This study covers a wide range of experimental conditions affecting the TL of powders: treatment time, plasma working gas composition, change of discharge configuration, step-annealing of powder, exposure to laser irradiation and aging time. Deconvoluted TL spectra were followed for the changes in their relative contributions. The TL spectra of all tested gases (air, Ar, N2 and 5% He in N2) consist of the well-known main dosimetric peak at 450 K and a peak of similar magnitude at higher temperatures, centered between 700 and 800 K depending on the working gas used. N2 plasma treatment gave rise to a new specific TL peak at 510 K, which exhibited several peculiarities. Initial thermal annealing of Al2O3 powders led to its significant amplification (unlike the other peaks); the peak was insensitive to optical bleaching, and it exhibited slow gradual growth during the long-term aging test. Besides its relevance to the ceramic processing studies, a comprehensive set of data is presented that provides a useful and unconventional view on plasma-mediated material changes.

Synthesis and characterization of Dy3 + doped lithium borate glass for thermoluminescence dosimetry

Lithium borate glass systems were synthesized to study their feasibility for measuring high radiation doses using thermoluminescence (TL) technique. Lithium borate glass with a composition (mol%) of 30Li2O–70B2O3 was prepared by conventional melt quenched technique. To see the effect of Dy3+ on thermoluminescence, photoluminescence and thermal properties of the glass, 0.5wt% of Dy2O3 was added prior to the glass making. One more glass with exact lithium tetraboarte (Li2B4O7) composition doped with 0.5wt% Dy2O3 was also prepared. Thermo-physical properties like density, and glass transition did not show significant changes with addition of Dy2O3. However, optical properties like band gap, UV visible absorption and photoluminescence showed substantial changes. The optical band gap decrease from 3.05 to 2.78eV with addition of Dy2O3. Photoluminescence (PL) analysis showed a broad emission at around 475nm in all the glasses and very sharp intense emission at 570nm for Dy2O3 doped glasses. After gamma irradiation in the dose range of 0.5–5kGy the samples exhibited TL peak at around 136 and 152°C for Dy2O3 doped lithium borate and tetraborate samples, respectively. A linear dose response in TL intensity was also observed which was useful for quantitative estimation of absorbed dose.

The contribution of hole traps to thermoluminescence of the dosimetric peak in anion-defect α-Al2O3 single crystals

The thermoluminescent properties of anion-defect alumina single crystals with different FWHMs of the main (dosimetric) peak at 400–500 K are studied. New experimental evidence in favor of the hole nature of traps associated with the high-temperature part of this peak are presented. The introduction of hole trap centers into analysis provided theoretical justification for the experimentally observed dependences of the thermoluminescence (TL) intensity, the temperature position of the main peak, and its FWHM on the occupancy of deep traps. The hole nature of traps of the high-temperature part of the main TL peak is confirmed by the results of examination of specific TL features of shallow trap centers, which govern TL at 350 K, and the temperature variation of the main TL peak spectrum.

Determination of trapping parameters in BeO ceramics in both quenched as well as reconstructed thermoluminescence glow curves using various analysis methods

The trapping parameters of BeO thermoluminescence peaks 2 and 3 (with delocalization temperatures of 192 and 308°C respectively, obtained with heating rate of 1K/s) have been calculated using various analysis techniques, including the peak shape methods, isothermal decay, variable heating rates, the fractional glow technique and de-convolution. However, as BeO has been reported to undergo thermal quenching, both intensity as well as trapping parameters are affected, because the glow curve is distorted. Therefore, trapping parameters were calculated for both quenched and unquenched data of the aforementioned thermoluminescence peaks. The unquenched glow curves were determined by reconstructing the corresponding quenched; the following thermal quenching parameters were adopted: W = 0.60eV and C = 1.3 × 106 for peak 2 and W = 0.80eV and C = 1.2 × 107 for peak 3. The obtained activation energies and frequency factors before and after reconstruction were compared both for every method and also to previous studies. This study emphasizes the importance of reconstruction process on trapping parameters for peak 3, as this peak lies within a special temperature range where the efficiency gets values < 0.54. The main dosimetric peak is mildly affected by thermal quenching; thus before and after reconstruction the corresponding values do not yield significant variations. The average values for the activation energy and frequency factor after reconstruction were calculated as 1.14 ± 0.07eV and 9.9 × 1010 ± 0.4 × 1010 s−1 for peak 2; the corresponding values for peak 3 are 1.34 ± 0.08eV, 6.9 × 1011 ± 0.6 × 1011 s−1 respectively. Both peaks are described by first order of kinetics even after reconstruction has occurred. Individual peculiarities of each analysis technique has been both presented and discussed.

Evaluation of the thermoluminescence kinetic parameters of zinc‐borosilicate glass after gamma‐irradiation

AbstractUp until this moment, there was no detailed study concerning the kinetic parameters of zinc‐doped borosilicate glass thermoluminescent (TL) material. A significant TL peak was observed upon gamma irradiating the samples, at around 185°C. Evaluating activation energy (E), frequency factor (s), and order of kinetics (b) were conventionally obtained by peak shape (PS) method, repeated initial rise (RIR), and variable heating rate (VHR) methods. The obtained results indicated that the zinc‐doped borosilicate glass glow curve after gamma irradiation is legitimately a superposition of seven interfered glow peaks. Therefore, we cannot use computerized glow curve deconvolution (CGCD) method alone in determining the kinetic parameters in this case. Additive dose (AD), repeated initial raise (RIR), and variable heating rate (VHR) methods together with computerized deconvolution (CGCD) method by using the TolAnal software have been applied to determine the kinetic parameters of zinc‐borosilicate glass due to the existence of several nearby overlapped peaks. RIR method gives the value of ± 2.3% average variation, for the activation energies, compared with those obtained by GCDC. The obtained results clearly show the consequences reliability.

OSL and TL retrospective dosimetry with leucite glass-based dental ceramics

Dental ceramics are radiation sensitive materials and exhibit luminescent properties. Their samples can be potentially used for individual dose assessment in situations where retrospective dosimetry is required. In this work, we investigated dosimetry properties of two leucite glass-based dental ceramics using Optically Stimulated Luminescence (OSL) and Thermoluminescence (TL). We concentrated on characteristics as reproducibility, fading, optical bleaching, minimum detectable dose (MDD), dose response and photon energy response of TL and OSL signals. Both the dental ceramics exhibited very good reproducibility (<5% at 2σ level) when irradiated and measured repeatedly. Their luminescence response was found to be linear for a wide range of doses up to 8.5 Gy. The MDD values for the samples investigated were a few mGy. The ceramics are not tissue equivalent materials, and their luminescent signals measured were strongly dependent on incident photon energy. Because of fading and optical bleaching the OSL and TL signals were not stable in time. Especially optical bleaching represents a main limiting factor for dose reconstruction. However, one of the ceramics provided a relatively resistant high temperature TL peak for dosimetry.

Studying CaSO4:Eu as an OSL phosphor

This study was carried out to investigate the properties of the OSL signal from Eu-doped calcium sulfate (CaSO4:Eu) phosphor and study on its thermal behavior as a function of temperature under a series of luminescence experiments. The suitability of its usage as an optically stimulated luminescence (OSL) dosimeter was also checked. CaSO4:Eu was synthesized using the precipitation method and prepared in pellet form. The dopant concentration value was performed as 0.1mol%. The synthesized CaSO4:Eu was analyzed by X-ray diffraction (XRD) method to confirm the product. To have an idea about the crystallography and microstructure morphology of the material, scanning electron microscope (SEM) analysis were carried out. It was found that the OSL signal is a resultant signal having three components and exhibits thermal quenching above 150°C. The excitation spectrum of CaSO4:Eu showed different peaks in the region 220–360nm with the highest one at 269nm. Thermoluminescence (TL) signals of CaSO4:Eu pellets were obtained and compared with the TL signals obtained after OSL measurements of the same pellets by blue light stimulation. The low temperature peak near 180 °C did not show any significant change in TL after OSL measurement whereas the high temperature peak at 240°C was bleached with the blue light illumination and might be responsible for the observed OSL signal.The dosimetric properties such as dose response, minimum detectable dose, energy response, reusability, fading properties, thermal stability and effect of reading temperatures on OSL signals were examined. OSL signals of CaSO4:Eu pellets were decreased by approximately 8% at the end of the 24h and by about 7% at the end of 28days when compared with the first readout. The thermal stability of the ∼240 °C TL peak and OSL signal using isothermal decay measurements were used to determine the trap parameters. The CaSO4:Eu OSL dosimeter in accordance with the presented study allows a high-sensitivity OSL phosphor whose host material was previously known as conventional synthetic CaSO4 TLD material.

Effect of particle size on the thermoluminescence dosimetric properties of household salt

This work investigates the effect of particle size on the thermoluminescence (TL) response of household salt that is classified into five size fractions between 63 and 250 μm. Irradiation induced two main TL peaks at 110 and 240 °C for each particle size fraction. In addition to these peaks, two additional glow peaks were observed at 80 and 300 °C for particles with small size (<90 μm). The complexity of the glow curve pattern increased with decreasing particle size (<125 μm). The intensity of the main dosimetric TL peak at 240 °C increased with increasing particle size. The maximum beta radiation sensitivity of the salt samples was obtained for the particle sizes of 125–180 and 180–250 μm. For different particle sizes, the stability of the dosimetric TL peaks at room temperature was studied over a storage period of 30 days. No systematic difference in the minimum detectable dose values observed for each grain size fraction and it was found to be 0.4 Gy for each grain size fraction. The kinetic parameters of the dosimetric TL peak were determined for different particle sizes using the initial rise and variable heating rate methods. Moreover, the variations in the glow peaks depending on the heating rate were also analyzed. While an expected behavior of low temperature TL at 110 °C was observed, an interesting heating rate behavior (anti-quenching) of the high temperature dosimetric TL peak at 240 °C was observed.

Features of an annealing-induced thermoluminescence peak in α-Al2O3:C,Mg

We report the thermoluminescence glow curves of beta irradiated single crystal α-Al2O3:C,Mg after annealing at 700 and 900 °C. A glow curve measured at 1 °C/s from samples irradiated to 1 Gy following annealing at 700 and 900 °C shows a high intensity peak at 163 °C and seven secondary peaks of weaker intensity at 43, 73, 100, 195, 280, 329 and 370 °C. Comparing the position of the peaks in the annealed samples with those in an un-annealed one, it is observed that the peak at 100 °C appears only after annealing at and above 700 °C. Kinetic analysis of this annealing-induced peak was carried out using the initial rise, whole glow peak, peak shape, curve fitting and variable heating rate methods. The order of kinetics of the peak was determined as first order using various methods including the Tm-Tstop technique and the dependence of Tm on irradiation dose. The activation energy of the peak is about 1.01 eV and the frequency factor of the order of 1012 s−1. The peak was found to be affected by thermal quenching in analysis based on change of peak intensity with heating rate. The activation energy of thermal quenching was evaluated as 1.06 ± 0.08 eV. We speculate that the annealing-induced peak is due to formation of a new electron trap after destruction of the F22+(2 Mg) centre when the sample is annealed at 700 °C. The annealing-induced peak fades with storage between irradiation and measurement. It was also concluded that electrons from traps corresponding to secondary peaks get re-trapped at the main electron trap.

Radioluminescence and thermoluminescence of rare earth doped and co-doped YF3

An investigation of the luminescent properties of undoped and rare earth (RE) singly- and co-doped YF3 was carried out by means of radioluminescence (RL) and thermoluminescence (TL) measurements. Materials were obtained by ligand-free co-precipitation with Ce, Tm, Tb or Eu substituting for Y, followed by calcination in air at 500 °C for 1 h. RL measurements confirmed the effective luminescence activation of the host. TL measurements revealed a relatively intense contribution of the host, with Tm doping yielding the strongest signal among the singly-doped samples. Co-doping with Ce and Tm was investigated within the 0.5–5 mol% range for each RE, with the 0.5,0.5 (Ce,Tm) mol% co-doping yielding the strongest luminescence signal. However, a clear correlation between the RE dopant(s) and TL peaks was not found.

Thermoluminescence in Lapis Lazuli crystal: Glow peaks and their connection with F-centers estimated by ESR analysis

The mineral Lapis Lazuli exhibits three thermoluminescence (TL) peaks approximately at 140, 260 and 370°C. The TL intensity of the three peaks grows with radiation dose and it saturates only beyond 9 kGy. Electron Spin Resonance (ESR) studies have been carried out to identify the defect centers responsible for the thermoluminescence peaks. The ESR spectrum of the as-received natural sample presented the typical six signals due to Mn2+ ion and a large signal around g=2.030 due to Fe3+ ion. Room temperature ESR spectrum of irradiated Lapis Lazuli shows the formation of a defect center. This center (center I) is identified as an F+-center (singly ionized oxygen vacancy) and seems to correlate with 140 and 250°C TL peaks. An additional defect center is observed during thermal annealing experiments and this center (center II - assigned to F+-center) appears to originate from an F-center (oxygen vacancy with two electrons). This F-center, precursor of center II, may be related to the observed high temperature 360°C TL peak in Lapis Lazuli.

Optically and thermally stimulated luminescence of CaB6O10:Ce,LiCl: Basic properties

The goal of the present investigation is to explore the optically stimulated luminescent (OSL) properties of CaB6O10:Ce,LiCl in order to verify its viability as detector of ionizing radiation. Here, we investigate basic dosimetric and luminescent properties of this material. To this end, we carried out radioluminescence (RL), thermoluminescence (TL) and OSL measurements. We investigated the dose-response to ionizing radiation, the luminescent emission spectra, stability of the TL signal, and lifetime of the associated luminescent centers. The crystalline phase was verified by X-ray diffraction. TL measurement shows that the material is highly sensitive to ionizing radiation with a dominant TL peak at ~290°C. RL measurement features a broad-band spectrum in contrast with the spectrum recorded during TL readout, which is narrow and was attributed primary to the 5d-4f transition from Ce3+. The time-resolved OSL is characterized by two fast components, namely, 70.1(6) ns and143(4) ns and thus, suitable for 2D laser scanning readout. Dose-response curve was linear over the tested range (2mGy−300Gy) without trend to saturation. The current drawback is the OSL signal fading of up to 80% within 24h by computing the initial intensity and of up to 50% by computing the integrated signal over 100s. In principle, this issue may be solved by a fast heating of up to 80°C prior to readout.

The influence of competition effects on the initial rise method during thermal stimulation of luminescence: A simulation study

The initial rise (IR) method is a widely used method to evaluate the activation energy of complex thermoluminescence (TL) glow-curves. It is generally accepted that competition effects take place among the various electrons traps responsible for the TL peaks of a glow curve. In the present study the potential influence of such competition effects on the IR method is studied. The simulation is divided in two parts. In the first part it is assumed that retrapping probabilities are lower than recombination probability. This simulation was carried out assuming either strong or weak competition from a thermally disconnected deep trap (TDDT). In the second part of the simulation the retrapping probabilities are assumed to be greater than the recombination probability. The simulation results showed that competition has serious effects on the resulting glow-curve shapes. Furthermore, the simulation showed that in most cases the IR method is able to reproduce accurately the input values of the activation energies of the three TL peaks. However, it was found that the IR method underestimated the activation energy of the last peak corresponding to the highest temperature by 8–20%, when the retrapping probabilities were higher than the recombination probability.