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In the present study, the dosimetric features of pink Himalayan salt pellets were studied. Energy dependence exhibited an over response up to 100 keV with a maximum factor of ~ 10 at 33 keV. The maximum angular dependence of ~ 46% was observed at 90° angle of incidence. The TL response was found to be dose rate independent and showed a good reproducibility with < 5% COV. The sample sensitivity was comparable to TLD-100 (beyond 500 mGy). The effective atomic number (Zeff) was found to be 15.20. Based on these dosimetric features, pink Himalayan salt can be a good potential candidate for therapeutic dosimetry applications. [ABSTRACT FROM AUTHOR]

In this study, the thermoluminescence characteristics of naturally occurring salt (NaCl) were assessed for the development of a radiation dosimeter. For this purpose, mined crystalline samples of salt were procured directly from Khewra salt mines in Pakistan. The samples were hand crushed, sieved, and compressed to pellets comparable in size to standard TLD chips, and irradiated to gamma radiation doses in the range of 5 mGy and 5000 mGy. Thermoluminescence (TL) response showed three main peaks in the glow curve around 115–130 °C, 150–170 °C, and 220–240 °C. A linear TL response was observed for the dose range of 5–100 mGy. The TL response became supra-linear for the dose ranges of 100–1000 mGy and 1000–5000 mGy. The Tm-Tstop method was applied to identify the overlapping peaks of the glow curve. Computerized glow curve deconvolution (CGCD) was then employed for the characterization of electron trap parameters such as frequency factor (s), activation energy (E), and the kinetic order (b), using General Order (GO) kinetics. The figure-of-merit (FOM) was found to be 1.08%, 0.94%, 0.77%, and 0.75%, at 500 mGy, 1 Gy, 2 Gy, and 5 Gy, respectively. The TL intensity faded by 20% within the first 24 h after irradiation and finally stabilized after two weeks. In addition, structural, morphological, and elemental analyses, were also performed using various analytical techniques. X-ray diffraction (XRD) showed that the salt crystallizes in a face-centered cubic structure. Scanning electron microscope (SEM) micrographs indicated that the crystallites are closely packed and cubic-shaped with non-uniform size, and mostly found in the agglomerated form. Similarly, the elemental analysis confirmed the presence of impurities such as Mg, Sr, S, K, O, and Ca, in the samples. The present study concludes that the pellets made from salt samples from Khewra mines have a potential for use as radiation dosimeters. [ABSTRACT FROM AUTHOR]

The mineral extraction activities may disturb the natural radioactivity, therefore current study aims to generate baseline data of natural radionuclides and anthropogenic 137Cs before the start of industrial activities. Gamma spectrometry and gross alpha and beta counting systems were used for activity measurement in environmental samples. In soil, the mean activity of 232Th, 226Ra, 40K and 137Cs were determined as 79 (66-117), 47 (34-80), 823 (602-1159) and 1.3 (1.1-4.5) Bq kg−1, respectively. The average annual effective dose rate (128.7 µSv h−1) in the study area was twice higher than world's average value. Indoor hazard index was greater than unity at two places; therefore, proper ventilation is proposed during construction. [ABSTRACT FROM AUTHOR]

The precision in measurement of trace level uranium isotopic ratio, i.e., 236U/238U or 234U/238U, on single Faraday detector with narrow dynamic range is very hard to achieve. this is mainly due to the narrow dynamic range of a single detector systems. A significant improvement in mass spectrometric determination of 236U/238U ratio has been achieved by employing an alternate method using a single Faraday detector of narrow dynamic range. The method makes use of the precise measurements of the 236U/234U ratio, 234U/235U ratio and 235U/238U ratio, which are used to calculate the 236U/238U ratio using the equation 236U/238U=236U/234U×234U/235U×235U/238U. Despite the fact that correlation of the data tends to increase the uncertainty in the result, our results show a significant improvement, i.e., more than 8 times better precision in measuring the 236U/238U ratio with this method ( σ=3.98×10−08) as compared to direct measurement of 236U/238U ( σ=3.104×10−07). The method widens the applicability of the single collector system with narrow dynamic range and it will potentially be helpful to improve the precision in the case of the static multi-collector system also. The objective of the present study was to compare the results of the same sample analyzed with the present alternate method and the direct method for precision. [ABSTRACT FROM AUTHOR]