## 4 Conclusions  
This investigation has evaluated several key TL parameters for windshield glass samples from Honda, Toyota and Proton motor vehicles, including tissue equivalence, TL glow curve, TL sensitivity, dose response, energy response and fading. Over the investigated gamma dose range of 1-100 Gy, the Honda windshield samples are seen to offer the greatest promise, with the greatest TL response and TL sensitivity. With SiO\({}_{2}\) the mainstay of glass, Energy Dispersive X-ray Spectroscopy confirms the unsurprising greater presence of both elements, the other various elements being additives that define the various performance properties that are of importance in providing for the needs of high-technology windshields. These same additives undoubtedly give rise to a good deal of the luminescence signal, although the role of the strain-related defects of curved windshields are also to be acknowledged; the effective atomic numbers (\(Z_{eff}\)) are found to be within the range 11.8-12.2, compared against the \(Z_{eff}\) of TLD-200 (16.3), the latter enjoying popular use in sensitive measurement of low-level environmental radiation. The presence of the other elements, including sodium, potassium, carbon, calcium, magnesium and aluminum, act as impurities which give rise to localized energy levels within the forbidden bandgap, underpinning the occurrence of an appreciable TL yield. Notably, the variation in Ca concentration between the studied windshield glass media is reflected in the TL sensitivity. The glow peaks for all glass samples show a maximum in TL yield for temperatures between 354-389 \({}^{\circ}\)C, supportive of the deep trapping (the activation energies are between 0.83 to 1.29 eV) that is needed for TL media that offer potential for use in retrospective dosimetry. All samples show energy dependency, a matter that needs to be accounted for in obtaining reliable estimates of dose. TL signal storage capability of the three media was investigated for a period of 28 days post-irradiation, demonstrating an ability to retain an appreciable signal for some tens of days post-irradiation. Windshield glass from Honda has been shown to possess the more favourable TL characteristic, a matter needing to be affirmed in more detailed investigations involving greater numbers of samples.  
Conceptualization, M.U.K.; methodology, D.A.B.; software, K.S.A.-m.; validation, S.F.A.S., A.S. and M.LS.; formal analysis, N.b.W.; investigation, N.b.W.; resources, S.F.A.S.; data curation, N.b.W.; writing--original draft preparation, N.b.W.; writing--review and editing, M.U.K. and D.A.B.; visualization, S.F.A.S., A.S. and M.R.I.F; supervision, M.U.K.; project administration, M.R.I.F.; funding acquisition, K.S.A.-m. All authors have read and agreed to the published version of the manuscript.  
Figure 7: Long-term fading of the TL signal, noting that during periods other than readout the samples are stored in the dark at ambient temperature (27 \({}^{\circ}\)C).  
**Funding:** This work was funded by Deanship of Scientific Research at Princess Nourah hint Abdulrahman University, through the Fast-track Research Funding (FRF) Program (grant no. 1000-ftfp-20).  
**Conflicts of Interest:** The authors declare no conflict of interest.