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artículo
An anhydrite (CaSO4) natural sample was studied as possible dosimeter for low and high gamma doses using the technique of electron paramagnetic resonance (EPR). EPR spectrum showed signals due to (SO3)(-), (SO4)(-) radicals and O center. The anhydrite sample was irradiated with gamma rays with low-dose ranges typical for medical therapy (1-20 Gy) up to high-dose of about 70 kGy. The EPR centers due to (SO3)(-) and (SO4)(-) exhibited a linear dose response in the dose range from 1 Gy to 500 Gy, whilst the 0 center presented a supra-linear dose response in the range of 50 to 5 kGy.
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artículo
MgCaSi2O6 polycrystal was synthesized by the devitrification method. The dosimetric characteristics by TL of this prepared polycrystal was investigated. This material exhibits TL peaks at 115, 160, 210, 260 and 280 °C. The dosimetric peak occurs at 260 °C with a well defined glow curve structure. This peak shows a linear dose response. Electron paramagnetic resonance (EPR) studies have been carried out to identify the defect centers responsible for the TL peaks. Two defect centers in the region of g = 2.0 are found. One of the centers (center I) with a g factor equal to 2.0085 is identified as O− -ion and relates with the observed high temperature 250 and 300 °C TL peaks. Additional defect centers with g = 2.0012 (center II) and 1.982 (center III) are due to F+- centers (electron trapped at an oxygen vacancy). Center II and III correlate with the TL peaks at 160 °C and 106 °C, res...
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