## 3 Results and Discussion
### Pre-Dose Sensitization
According to the Goedicke model, this peak is a competitor, and it is thermally linked to high temperatures ranging from 550 \({}^{\circ}\)C to 700 \({}^{\circ}\)C. Qualitatively, the peak observed at 315 \({}^{\circ}\)C may be attributed to the thermally displaced electrons into the conduction band of phyllite. The creation of thermal electrons may cause a reduction in sensitivity at temperatures greater than 550 \({}^{\circ}\)C, and consequently, radiative recombination of the relaxed electrons with the trapped holes occurs. Mixing the pre-dose with thermal sensitization increases S/S\({}_{0}\) by values that depend on the test dose, that is, for a test dose of 1 Gy, the ratio S/S\({}_{0}\) is found to have a value about \(\cong\)13 \(\pm\) 0.33. Following [PERSON]'s argument, the extra holes concentration existing at the luminescence center is the direct cause for the higher response to a subsequent test dose. However, [PERSON] [5] highlighted the observation that the finally measured TL is proportional to the filling of L level, and there is a linear dependence on the value of the test dose. Sensitization effects are clearly observed when reservoir R shows saturation effects. [PERSON] and [PERSON] et al. [24] argued that the initial use of a high test dose may mean that part of the effect is due to the combination of irradiation plus heating. Therefore, the present results could be explained on the basis of defect creation (vacancies) in the crystal structure of the investigated material. Growth curves: for an unsensitized phyllite sample, the dose-response of the TL (Figure 5a) had two ranges of variation with two different slopes:  
1. Linear behavior (y = 301.88 + 35.103x) in which the linear change covers the dose range 0.1-5 Gy. The linearity index has an average value of 0.9539;
2. Superlinear behavior (y = 46.46x\({}^{1.1}\)) in which the superlinear change is in the dose range > 5-10\({}^{3}\) Gy. Figure 4: Variation of glow curves with the activation temperature. In the previous equations (linear and superlinear), y represents the TL intensity per gm, and x is the given dose in Gy. As shown in Figure 5b, the linear dependence of the sensitized phyllite (y = 275.89 + 22.029x) in the dose range of 1 up to 10\({}^{3}\) Gy with the linearity index in the range 0.98 to 1.01 is presented. The model suggested by [PERSON] and [PERSON] is used to explain the results depicted in Figure 5a as follows:  
Figure 6 displays the glow curves of the unsensitized and sensitized phyllite. The unsensitized sample (Figure 6a) has 4 TL peaks observed at 75 \({}^{\circ}\)C, 115 \({}^{\circ}\)C, 250 \({}^{\circ}\)C, and 315 \({}^{\circ}\)C, respectively. Figure 5: Growth curves of phyllite as a function of gamma dose: (**a**) unsensitized sample and (**b**) sensitized sample. The calculated standard deviation is within 5%. Figure 6: Variation of TL glow curves of (**a**) unsensitized phyllite and (**b**) sensitized phyllite with test dose 1 Gy. In the sensitized material, it was assumed that the peak that exists at 315 \({}^{\circ}\)C became thermally linked to the conduction band that exists at 550 \({}^{\circ}\)C, so its traps were emptied, as shown in Figure 6b. The TL dose-response of the sensitized phyllite is linear, which is in agreement with previously published reports [21; 22; 23]. The pre-dose technique was quite suitable for heated samples such as phyllite; the same result was found and reported previously forquartz. In the literature, the effect of sensitization was studied for many purposes, such as to investigate the source of point defects, to measure the variation of responses between different aliquots of the same sample, and to infer the temperature at which the natural material was heated in the past. [PERSON] et al. found that photo transfer thermoluminescence (PTTL) increased the sensitization effect, while prolonged blue light exposure decreased it.