Abstract
Magnesium borate (MgB4O7) is a highly sensitive phosphor commonly used in a thermoluminescence (TL) dosimeter. In this work we report on TL response of nanocrystalline MgB4O7:Dy irradiated by 3 MeV proton beam as well as 50 MeV Li3+ and 120 MeV Ag9+ ion beams in the fluence range of 1 x 10(11)-1 x 10(15) ions/cm(2). The induced TL glow curves were compared with that of gamma rays irradiation. A single glow peak is observed at around 430 K in the samples irradiated by Li3+ and Ag9+ ions, while that exposed to proton beam has an extra one at 525 K. This nanomaterial has maximum sensitivity to Li3+, then Ag9+ ions and finally protons. The TL response curves of the samples exposed to these radiations are linear/sublinear at the lower fluences, while at higher values they saturate. These variations in the glow curve structure and TL response could be attributed to the modifications created in the traps/luminescent centres. TRIM code was also used to calculate the absorbed doses, penetration depths and main energy loss. The results show that this nanomaterial might be useful for the dosimetry of heavy charged particles such as Li3+ and Ag9+ particularly at low fluences, while in case of proton beam the TL glow curve is greatly altered and shows poor sensitivity. (C) 2013 Elsevier Ltd. All rights reserved.