Techniques and problems of low-level gamma-ray spectrometry

Westmeier, W.

doi:10.1016/0883-2889(92)90102-k

Cited by 18 publications

(6 citation statements)

References 40 publications

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“…The detector was shielded by 15-cm-thick lead wall provided with 3-mm-thick copper and 4-mm-thick tin inner lining in order to effectively reduce the natural background. The inner size of shielded cavity was 25 × 25 cm 2 (Heusser et al 1989;Westmeier 1992). The system was calibrated using IAEA soil-326, and reliability of counting efficiency was confirmed using soil-375 reference material.…”

Section: Gamma Spectrometric Analysismentioning

confidence: 99%

Measurement of soil radioactivity levels and radiation hazard assessment in southern Rechna interfluvial region, Pakistan

Jabbar

Arshed

Bhatti

et al. 2009

Environ Monit Assess

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Rechna interfluvial region is one of the main regions of Punjab, Pakistan. It is the area which is lying between River Ravi and River Chenab, alluvial-filled. Radioactivity levels in soil samples, collected from southern Rechna interfluvial region, Pakistan, have been estimated by using gamma-ray spectrometric technique. (226)Ra, (232)Th, the primordial radionuclide (40)K, and the artificial radionuclide (137)Cs have been measured in the soil of the study area. The mean radioactivity levels of (226)Ra, (232)Th, (40)K, and (137)Cs were found to be 50.6 +/- 1.7, 62.3 +/- 3.2, 662.2 +/- 32.1, and 3.1 +/- 0.3 Bq kg(-1), respectively. The mean radium equivalent activity (Ra(eq)), outdoor radiation hazard index (H(out)), indoor radiation hazard index (H(in)), and terrestrial absorbed dose rate for the area under study were determined as 190.8 +/- 8.7 Bq kg(-1), 0.52, 0.65, and 69.8 nGy h(-1), respectively. The annual effective dose to the general public was found to be 0.43 mSv. This value lies well below the limit of 1 mSv for general public as recommended by the International Commission on Radiological Protection. The measured values are comparable with other global radioactivity measurements and are found to be safe for the public and the environment.

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Section: Gamma Spectrometric Analysismentioning

confidence: 99%

Measurement of soil radioactivity levels and radiation hazard assessment in southern Rechna interfluvial region, Pakistan

Jabbar

Arshed

Bhatti

et al. 2009

Environ Monit Assess

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“…where a l is an additional normalizing model parameter for each FEP. For the baseline, a physics-oriented empirical model was adopted (Westmeier, 1992). Weighted non-linear least-squares (WNLLS) regression using the interior-reflective Newton method (Coleman and Li, 1996) was utilized to determine the 3N pk statistical model parameters, i. e. a l , µ l and σ l as well as corresponding standard deviation values σ a l , σ µ l and σ σ l with l ∈ {1, .…”

Section: Spectral Postprocessingmentioning

confidence: 99%

Experimental and Simulated Spectral Gamma-Ray Response of a NaI(Tl) Scintillation Detector used in Airborne Gamma-Ray Spectrometry

et al. 2022

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Abstract. The objective of this work is to simulate the spectral gamma-ray response of NaI(Tl) scintillation detectors for airborne gamma-ray spectrometry (AGRS) using the state-of-the-art multi-purpose Monte Carlo code FLUKA. The study is based on a commercial airborne gamma-ray spectrometry detector system with four individual NaI(Tl) scintillation crystals and a total volume of 16.8 L. To validate the developed model, radiation measurements were conducted using 57Co, 60Co, 88Y, 109Cd, 133Ba, 137Cs and 152Eu calibration point sources with known activities and source-detector geometries under laboratory conditions. In addition, empirical calibration and resolution functions were derived from these measurements combined with additional radiation measurements adopting natural uranium, thorium and potassium volume sources. The simulation results show superior accuracy and precision compared to previous AGRS simulation models with a median relative spectral error < 10 % for most of the radiation sources. Moreover, the implementation of a lower level discriminator model and detailed modelling of the laboratory result in a significant improvement in model accuracy for spectral energies < 100 keV compared to previous studies. Yet thorough statistical analysis incorporating statistical and systematic uncertainty estimates revealed statistically significant deviations between the simulated and measured spectra in the spectral region around the Compton edge, which could be attributed to the scintillator non-proportionality. These findings imply that the linear energy deposition model applied in this and previously developed AGRS simulation models should be revised and considered to be replaced by more accurate non-proportional models.

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“…The energy resolution of the system was 2.0 keV (FWHM) at 1332 keV from 60 Co. The detector was shielded [33,34] …”

Section: Sample Analysismentioning

confidence: 99%

Transfer of radioactivity from soil to vegetation in Rechna Doab, Pakistan

Jabbar

Tufail

Arshed

et al. 2010

Isotopes in Environmental and Health Studies

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In Rechna Doab, samples of the most common vegetation, perennial grass Desmostachya bipinnata (dab), were collected along with soil samples from 29 sites. Natural radioactivity of ²²⁶Ra, ²³²Th/²²⁸Ac and ⁴⁰K was measured by using high purity germanium-based gamma ray spectrometer. Activity concentration levels of ²²⁶Ra, ²³²Th/²²⁸Ac and ⁴⁰K in soil were found to be 46.8 ± 6.2 (36.0-57.6), 61.4 ± 5.9 (48.2-73.2) and 644.8 ± 73.9 (537.7-868.4) Bq kg⁻¹ (dry mass), respectively, and those in vegetation were 2.74 ± 1.70 (1.00-6.39), 2.24 ± 0.59 (1.56-2.61) and 172.72±113.37 (53.14-469.24) Bq kg⁻¹ (dry mass), respectively. The measured values of the activity concentration in vegetation are comparable with some other international data. Calculated soil to vegetation transfer factors of ²²⁶Ra, ²²⁸Ac and ⁴⁰K were 0.06 ± 0.03 (0.02-0.14), 0.04 ± 0.01 (0.03-0.04) and 0.26 ± 0.16 (0.09-0.69). The mean outdoor absorbed dose rate in air for the area under study was determined as 8.22 nGy h⁻¹ and the mean indoor absorbed dose rate in air was 11.52 nGy h⁻¹. The total annual effective dose to the general public from the vegetation was found to be (0.02-0.16) mSv, which is below the recommended limit value of 1 mSv y⁻¹ for the general public. The dab vegetation under study was found to be radiologically safe for the population and environment.

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Techniques and problems of low-level gamma-ray spectrometry

Cited by 18 publications

References 40 publications

Measurement of soil radioactivity levels and radiation hazard assessment in southern Rechna interfluvial region, Pakistan

Measurement of soil radioactivity levels and radiation hazard assessment in southern Rechna interfluvial region, Pakistan

Experimental and Simulated Spectral Gamma-Ray Response of a NaI(Tl) Scintillation Detector used in Airborne Gamma-Ray Spectrometry

Transfer of radioactivity from soil to vegetation in Rechna Doab, Pakistan

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