Fabricated Ge-doped flat optical fibres: Assessing the thermoluminescence glow curves for proton beam irradiation

Abstract

We investigate the fundamental characteristics of thermoluminescence (TL) glow curves on the fabricated 2.3 and 6.0 mol% germanium (Ge) doped flat optical fibres subjected to proton beam irradiation. The novel fabricated flat Ge-doped optical fibres used in this study were manufactured using a modified chemical vapour deposition (MCVD) based technique. TLD-100 dosimeters and commercial optical fibres (CorActive High-Tech Inc., Canada) were employed to allow for comparable TL response of the fabricated flat optical fibres. The proton beam irradiations were carried out using a 150-MeV proton beam energy over the radiation doses in the range from 1 to 5 Gy. A Harshaw™ 3500 TLD reader was used to read out the given radiation dose to the samples. The results show that the general structure of the TL glow curve for the fabricated flat optical fibres remains unchanged independently within the investigated radiation dose range. Apparently, the fabricated 2.3 mol% Ge-doped flat optical fibres have the most ideal TL glow curves characteristic, representing a single peak distribution, whereas the double peaks distributions were observed for a 6.0 mol% Ge-doped flat optical fibre. All optical fibres were considerably high glow peak temperatures that suggesting the presence of deep-trapped electrons. This convenient position at relatively high temperature will open the way for such optical fibres to be used not only in proton radiotherapy dosimetry, but also in high temperature and difficult-to-access areas, such as that of nuclear power plants.