Determination of the Depth of Localized Radioactive Contamination by Cs-137 and Co-60 in Sand with Principal Component Analysis

作者：Adams Jamie C^*; Mellor Matthew; Joyce Malcolm J

来源：Environmental Science & Technology, 2011, 45(19): 8262-8267.

DOI：10.1021/es201619r

A method to determine the depth of buried localized radioactive contamination nonintrusively and nondestructively using principal component analysis is described. The gamma-ray spectra from two radionuclides, cesium-137 and cobalt-60, have been analyzed to derive the two principal components that change most significantly as a result of varying the depth of the sources in a bespoke sand-filled phantom. The relationship between depth (d) and the angle (theta) between the first two principal component coefficients has been derived for both cases, viz.
d(phi) = x y log(e) phi
where x and y are constants dependent on the shielding material and the gamma-ray energy spectrum of the radioactivity in question, and phi is a function of theta. The technique enables the depth of a localized radioactive source to be determined nonintrusively in the range 5 to 50 mm with an accuracy of +/- 1 mm.

• 出版日期2011-10-1