ABSTRACT
In this study, we have synthesized B doped Ca5(PO4)3OH (HAP) by a sonication chemical method. The thermoluminescence (TL) properties of the family of synthesized samples (B doped Ca5(PO4)3OH (HAP) were investigated using an IRSL-TL 565 nm filter. This gave the highest TL intensity of each phosphor after 2 Gy ß-irradiation. Three TL glow peaks of B doped Ca5(PO4)3OH (HAP) are centered at around 84, 208 and 324 °C (with a heating rate of 2 °Cs-1). The trapping parameters such as activation energy (E), order of kinetics (b), frequency factor (s) were calculated by using initial rise (IR), various heating rates (VHR) and computerized glow curve deconvolution (CGCD) method. The response of TL glow curves remained constant within ±5% deviation from the initial value after 9 cycles of reuse; but only at tenth cycle the deviation goes up to 6%.
ABSTRACT
It is worth to continuous and systematic investigations related with magnesium tetraborate (MBO) due to its attractive candidate for dosimetric application. The study was done to develop new phosphor with adding strontium (Sr) into MBO which was prepared by the simple high temperature solid state method. Its main dosimetric properties, like glow curve structure, dose response, trapping parameters and fading, were investigated for the first time in the literature. The experimental results indicated that Sr doped MBO ensured essential characteristics for applicability in medical dosimetry, except for the fading (45% lost in 7 days) feature. It had main glow peak with highest intensity at nearly 200⯰C with good linearity of the dose-response up to 1150â¯Gy. This study suggests that Sr-doped MBO is a promising material for dosimetric application, just need to solve the fading problem with addition of another activators as a co-dopant.
ABSTRACT
Strontium was used for the first time as an activator agent for magnesium tetraborate (MBO) and photoluminescence (PL) and thermoluminescence (TL) properties were determined using a spectrophotometer and a TL reader, respectively. The results proved that 0.25wt% Sr ratio played an important role in prolonging the afterglow and the phosphor gave the main TL peak with the highest intensity at 200°C like an ideal case. Therefore, it is worthwhile to carry out continuous and systematic research on it.
ABSTRACT
In this paper, the thermoluminescence (TL) dosimetric characteristics of MgO doped natural amethyst samples (Mg-NA) are presented. The morphologies and chemical structures of the powder form samples were identified using XRD, FTIR, SEM, SEM mapping and EDX. Comparison of the TL intensities showed that 10wt% Mg-NA was nearly 150 times more sensitive than undoped amethyst and the main dosimetric properties proved that 10wt% Mg-NA may be a promising phosphor for clinical and radiotherapy purposes.
