Characterization of ferrous-methylthymol blue-polyvinyl alcohol gel dosimeters using nuclear magnetic resonance and optical techniques
Abstract
A new composition of Ferrous sulphate-Metheylthymol blue (MTB)-Polyvinyl alcohol (PVA) dosimeter is introduced in this work and evaluated using nuclear magnetic resonance (NMR) and absorbance spectrophotometry techniques. The Fricke-MTB-PVA dosimeters were irradiated using a medical linear accelerator in a cubic water phantom. The dose response of the dosimeters was investigated using NMR in terms of spin-spin relaxation rate (R2), and ultraviolet and visible regions (UV-Vis) spectrophotometry in terms of absorbance. The dosimeter presents a linear dose response for doses up to 20 Gy with UV-Vis and 40 Gy with NMR method. The sample with 0.1 mM MTB, 5% PVA by weight showed highest dose sensitivity for both techniques. The Fricke-MTB-PVA dosimeter developed in this work has a significant advance over the Fricke-MTB-gelatin system: the NMR sensitivity was remarkably improved; the auto-oxidation rate was seven times lower, and no significant dose rate or photon energy effects were observed.
- Publication:
-
Radiation Physics and Chemistry
- Pub Date:
- July 2018
- DOI:
- 10.1016/j.radphyschem.2018.02.019
- Bibcode:
- 2018RaPC..148...25R
- Keywords:
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- Fricke gels;
- Methylthymol blue dye;
- Polyvinyl alcohol;
- Radiation dosimetry;
- Nuclear magnetic resonance;
- Spectrophotometry