The nanoparticles of BaSO_4:Eu as detectors for high doses of different ionising radiations

摘要

Nanoparticles of a BaSO_4:Eu phosphor with a particle size of around 40 nm have been irradiated by 48 MeV ~7Li~(3+), 75 MeV C~(6+) and 90 MeV O~(7+) ion beams at the fluence range of 1 × 10~9-1 × 10~(13) ions/cm~2. The thermoluminescence (TL) glow curves of the irradiated samples were recorded and studied. The microcrystalline form of this sample is included in the study with the aim of reporting a comparative measurement. The TL results of this material in its nano- and microforms exposed to the gamma rays of ~(60)Co are also included and investigated in more detail. It is observed that the glow curves of the nanomaterial exposed to these ions are similar to that exposed to gamma rays, with a dosimetric peak at 462 K beside a smaller one at 503 K, while those of the microcrystalline sample exposed to both ion beams and gamma rays have their prominent peak at 503 K beside a smaller one at 462 K. The observed TL sensitivity of the nanocrystalline material is less than that of the microcrystalline sample at low fluences/doses, while it is more at higher fluences/doses. This nanophosphor exhibits a linear/sublinear TL response to energetic ions and gamma radiation over a very wide range of exposures, which is much wider compared to that of its microcrystalline counterpart. This makes the nanostructural form of BaSO_4:Eu useful to estimate the high doses of different ionising radiations that are in use for radiotherapy or food/seed irradiation.