A new technique for processing airborne gamma ray spectrometry data for mapping low level contaminations

Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim; Hovgaard, Jens

doi:10.1016/s0969-8043(99)00087-1

Cited by 25 publications

(8 citation statements)

References 2 publications

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“…At sea level, it is predominantly due to terrestrial gamma-rays and to lesser degree cosmic-ray-induced gamma-rays. Accordingly, in the present study we analyse five similar measured natural background gamma-radiation pulseheight spectra (three from the USA and two from Europe), as collected using NaI(Tl) detectors of similar size (Lowder et al 1964;Blum et al 1997;Aage et al 1999;Busby 2005;Redus et al 2007). From these spectra, we calculated a single weighted-average spectrum curve (figure 2).…”

Section: Natural Background Gamma-radiation Spectrummentioning

confidence: 99%

Enhancement of natural background gamma-radiation dose around uranium microparticles in the human body

Pattison

Hugtenburg

Green³

2009

J. R. Soc. Interface.

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Ongoing controversy surrounds the adverse health effects of the use of depleted uranium (DU) munitions. The biological effects of gamma-radiation arise from the direct or indirect interaction between secondary electrons and the DNA of living cells. The probability of the absorption of X-rays and gamma-rays with energies below about 200 keV by particles of high atomic number is proportional to the third to fourth power of the atomic number. In such a case, the more heavily ionizing low-energy recoil electrons are preferentially produced; these cause dose enhancement in the immediate vicinity of the particles. It has been claimed that upon exposure to naturally occurring background gamma-radiation, particles of DU in the human body would produce dose enhancement by a factor of 500–1000, thereby contributing a significant radiation dose in addition to the dose received from the inherent radioactivity of the DU. In this study, we used the Monte Carlo code EGSnrc to accurately estimate the likely maximum dose enhancement arising from the presence of micrometre-sized uranium particles in the body. We found that although the dose enhancement is significant, of the order of 1–10, it is considerably smaller than that suggested previously.

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Section: Natural Background Gamma-radiation Spectrummentioning

confidence: 99%

Enhancement of natural background gamma-radiation dose around uranium microparticles in the human body

Pattison

Hugtenburg

Green³

2009

J. R. Soc. Interface.

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“…Commonly used analysis techniques utilize the counts in certain spectral energy windows to measure and map background levels or to detect sources, and these approaches generally trade statistics for specificity to particular radioactive isotopes [5], [6], [7]. Other techniques have been developed to leverage the information contained across the entire spectrum, thus gaining statistics but potentially losing specificity [8], [9], [10], [11]. Though potentially more powerful than windowed approaches, these techniques require detailed modeling of the different background components in order to compensate for the loss of specificity.…”

Section: Introductionmentioning

confidence: 99%

Modeling Aerial Gamma-Ray Backgrounds Using Non-negative Matrix Factorization

Bandstra

Joshi

Bilton

et al. 2020

IEEE Trans. Nucl. Sci.

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Airborne gamma-ray surveys are useful for many applications, ranging from geology and mining to public health and nuclear security. In all these contexts, the ability to decompose a measured spectrum into a linear combination of background source terms can provide useful insights into the data and lead to improvements over techniques that use spectral energy windows. Multiple methods for the linear decomposition of spectra exist but are subject to various drawbacks, such as allowing negative photon fluxes or requiring detailed Monte Carlo modeling. We propose using Non-negative Matrix Factorization (NMF) as a data-driven approach to spectral decomposition. Using aerial surveys that include flights over water, we demonstrate that the mathematical approach of NMF finds physically relevant structure in aerial gamma-ray background, namely that measured spectra can be expressed as the sum of nearby terrestrial emission, distant terrestrial emission, and radon and cosmic emission. These NMF background components are compared to the background components obtained using Noise-Adjusted Singular Value Decomposition (NASVD), which contain negative photon fluxes and thus do not represent emission spectra in as straightforward a way. Finally, we comment on potential areas of research that are enabled by NMF decompositions, such as new approaches to spectral anomaly detection and data fusion.

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“…This method has been successfully used for geological mapping, uranium exploration, and mineral resources exploration since it was first used for oil and gas prospecting in the 1960s [1][2][3][4]. The applications of the method have been expanded to environmental estimation of ionization radiation and the determination of Cesium-137 radioactive concentration in soil after the chernobyl nuclear reactor accident throughout Sweden, Russia, France, and so on [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Mapping the terrestrial air-absorbed gamma dose rate based on the data of airborne gamma-ray spectrometry in southern cities of China

Xiong

Wang

Fan

et al. 2012

Journal of Nuclear Science and Technology

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An environmental radioactivity survey by Airborne Gamma-ray Spectrometry (AGS) on a large scale was undertaken in Zhuhai Zone (ZZ) and Shenzhen Zone (SZ), which include major cities in southern China, covering areas of 3800 km 2 and 4660 km 2 , respectively. The estimated dose rates by AGS have been compared with observed results by ionization chamber and portable dosemeter. Maps of the terrestrial dose rate at 1m above ground level have been calculated based on the data of AGS. The mean dose rates are 84.37 + 51.69 and 82.10 + 32.98 nGy/h in ZZ and SZ, and the maximum rates are 343.11 and 368.36 nGy/h, respectively. Dose rates in some places are above 180 nGy/h; the areas covered where 149 km 2 in ZZ and 43 km 2 in SZ. The dominant geological conditions that evidently contribute to the radioactive anomalies are outcrops of Middle and Late Jurassic and Cretaceous biotitic-granite. The growth of industrialization and urbanization has dramatically altered radiation background. Stone mining results in the increase of radiation levels with maximum dose rates approaching 368.36 nGy/h in an open pit. The investigation results provide valuable background data and give a good example for mapping nationwide natural radiation terrestrial dose rates in China by AGS.

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A new technique for processing airborne gamma ray spectrometry data for mapping low level contaminations

Cited by 25 publications

References 2 publications

Enhancement of natural background gamma-radiation dose around uranium microparticles in the human body

Enhancement of natural background gamma-radiation dose around uranium microparticles in the human body

Modeling Aerial Gamma-Ray Backgrounds Using Non-negative Matrix Factorization

Mapping the terrestrial air-absorbed gamma dose rate based on the data of airborne gamma-ray spectrometry in southern cities of China

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