A Co‐Precipitated α‐Alumina (Al₂O₃) used as a TL‐Micro Dosimeter

Abstract

This study describes the preparation method of alumina (Al 2 O 3 ) as a type of thermoluminescence dosimeter (TLD) to monitor gamma photons (γ-rays) in abroad band of radioactive doses (0.5 : 2000 Gy). Alumina is selected in this study because it has a relatively low cost TL material and can be easily prepared. Aluminum oxide (Al 2 O 3 ) was chemically prepared using two different methods which are the Sol-Gel and Co-precipitation methods. For each method, the produced alumina (Al 2 O 3 ) was divided into 4 groups which was thermally treated at (400, 600, 800, 1100°C) respectively for 6 hours for each group. The crystalline features, morphology and sample composition of the prepared samples were chemically characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX). Al 2 O 3 prepared by the Coprecipitation method which was treated at 1100°C (P4) was found to exhibit the highest gamma ray response compared to other samples. The deconvolution analysis showed that the main TL glow curve consisted of ( 5) overlapped peaks corresponding to number of traps. The linearity of the gamma response for this sample appeared in doses ranging from 1 Gy up to 200 Gy. The minimum detectable dose that can be detected by precipitated-alumina sample (P1) was calculated mathematically to be 3.653 mGy. The fading was found to be 45.6 % after being stored for 45 days at room temperature and approximately 65 % after 90 days. This sample was reproducible according to the repeated TL results for the same sample for 5 times as their values were very close from one other with standard deviation (� σ) 0.96 %. Henceforth, Co-precipitated αalumina can be used as a TL-Micro dosimeter.