Optical Materials 120 (2021) 111472 Available online 14 August 2021 0925-3467/© 2021 Elsevier B.V. All rights reserved. Research Article Passive dosimetry of β-irradiated lithium borate doped glass Nabil El-Faramawy a, * , Huda Alazab b , Shrouk Rawash a , Nashat Diab c , Mohamed El-Kinawy a a Department of Physics, Faculty of Science, Ain Shams University, 11566, Abbassia, Cairo, Egypt b Nuclear and Radiological Regulatory Authority, 3-Ahmed El-Zomor St. El-Zohour Sect, Nasr City, 11762, Cairo, Egypt c National Cancer Institute, Cairo University, Giza, Egypt A R T I C L E INFO Keywords: TL dosimeters Borate glass Deconvolution Rare elements Dosimetric properties ABSTRACT This study investigates the role of doping lithium tetraborate glass (Li 2 B 4 O 7 ) with Mg and Tb on the TL dosi- metric properties of the glass samples. Glass samples doped with both Mg and Tb were prepared using a melting method at 1000 ◦ C. Beta particles were used as a source of ionizing radiation. The optimum combination of doping Mg and Tb to the glass samples was determined by doping Mg frst and then adding Tb to the best concentration of Mg. The crystal structure of the virgin glass samples, the samples doped with Mg, and the samples doped with Mg and Tb were probed using XRD. The TL glow curve of the glass samples doped with the optimum combination of Mg and Tb was recorded and analyzed using different methods. To estimate the number of TL components in the glow curves, T m –T stop method was used. Kinetic parameters of the glow peaks were determined using CGCD and peak shape methods. TL dosimetric properties of the samples doped with the op- timum combination of Mg and Tb, such as dose-response linearity, sensitivity, reproducibility, minimum detectible dose, and thermal fading were also characterized. 1. Introduction Over the past years, new nuclear facilities have been constructed all over the world. As a consequence of this increase in nuclear facilities, the nuclear background radiation has also been increasing. This increase in the radiation background poses a serious demand to possess appropriate tools to monitor radiation levels in different situations. One wide-used and reliable tool to do so is solid state dosimeters [1]. Upon interac- tion with ionizing radiation, solid state dosimeters store the incident radiation energy until being extracted again. Different forms of energy can be used to retrieve this stored energy in the form of visible light (luminescence). One possibility of restoring this stored energy is to use thermal energy, the phenomenon which is called thermoluminescence (TL) [2,3]. Thermoluminescent dosimeters display luminescence upon heating via possessing impurities. The energy levels of these impurities reside between the top of the valence band and the bottom of the conduction band [4]. The incident ionizing radiation produces free electron-hole pairs. These free-induced charges get trapped in the impurity energy levels. Heating the dosimeter to suitable temperatures frees these trap- ped charges, giving rise to radiative recombination events. The intensity of these events with respect to the heating temperature is called the glow curve. These events carry information about the incident radiation (the intensity of these events) and about the internal structure of the dosimeter (profle of the events). Solid state dosimeters can be natural without controlling the types of impurities in the material, or they can be cooked with specifc dopants to a host material. Among solid state dosimeters, glass ones have the advantage of being transparent which reduces scattering and absorption of emerging TL light [5,6]. Glass dosimeters come in different shapes and phases, e.g. phosphate glass, borosilicate glass, fuorophosphate glass, borate glass, lithium borate glass … etc. Extensive work has been and is being done to improve the TL dosimetric properties (sensitivity, linear response to absorbed dose, and thermal stability) of glass do- simeters modifed by dopants [7–16]. Among glass dosimeters, borate glass compounds attract considerable concern due to their high sensi- tivity, low cost, and ease of preparation. The current study was aimed to study and investigate the role of doping lithium borate glass with Magnesium (Mg) and Terbium (Tb) on the TL dosimetric properties. The optimum combination of doping the glass samples with Mg and Tb, which displays the highest TL response, was determined and characterized. The study reports the structural characterization of the base samples, glass samples doped with Mg, and the samples doped with Mg and Tb. Kinetic parameters of the optimum * Corresponding author. Physics Department, Faculty of science, Ain shams University, 65511, Abbassia, Cairo, Egypt. E-mail address: nabil_elfaramawi1@sci.asu.edu.eg (N. El-Faramawy). Contents lists available at ScienceDirect Optical Materials journal homepage: www.elsevier.com/locate/optmat https://doi.org/10.1016/j.optmat.2021.111472 Received 20 March 2021; Received in revised form 25 July 2021; Accepted 9 August 2021