Thermoluminescence properties of Al2O3:Tb nanoparticles irradiated by gamma rays and 85 MeV C6+ ion beam

Abstract

Carbon ions beam is recently recognized as an ideal cancer treatment modality, because of its excellent local tumor control. These ions have a high relative biological effectiveness resulting from high linear energy transfer (LET) and their sharp Bragg peak. However, the dose of those energetic ions needs to be measured with great precision using a proper dosimeter. Aluminum Oxide (Al2O3) is a highly luminescent phosphor widely used for radiation dosimetry using thermoluminesence (TL) technique. In this work nanoparticles of this material activated by different elements like Eu, Tb, Dy, Cu and Ag were evaluated for their TL response to gamma rays irradiation. Tb doped sample is found to be the most sensitive sample, which could be selected for exposure to 85MeV C6+ ion beam in the fluence range 109–1013ions/cm2. The obtained result shows that C ion beam irradiated sample has a simple glow curve structure with a prominent glow peak at around 230°C. This glow curve has a dosimetric peak better than those induced by gamma rays. This glow peak exhibits a linear response in the range 109–1011ions/cm2, corresponding to the equivalent absorbed doses 0.285–28.5kGy. The absorbed doses, penetration depths and main energy loss were calculated using TRIM code based on the Monte Carlo simulation. The wide linear response of Al2O3:Tb nanoparticles along with the low fading makes this low cost nanomaterial a good candidate for C ion beam dosimetry.