Emission probabilities of L X-, K X- and γ-rays in the 10–130 keV range following the decay of 239Pu

Abstract

X- and γ-ray emission probabilities in the 10–130 keV range were accurately measured for 239Pu using calibrated Ge detectors. Data below 60 keV are essential for the development of environmental and contamination measurement techniques; data above 60 keV are required mainly for nondestructive analyses applicable to nuclear material safeguards. X- and γ-ray spectra were obtained from an electroplated 239Pu source with an activity of 0.5 MBq using calibrated collimated planar-Ge and coaxial-Ge detectors. An additional electroplated source of 3 MBq 239Pu was counted to improve the spectrum analysis in the K X-ray region. L and K X-ray peaks were fitted to Voigt functions while γ-ray peaks were described by Gaussian functions; anomalous K X-ray line shapes were observed from the decay of 239Pu. The principal X- and γ-ray emission probabilities were determined with an uncertainty of 1% or better. For example, the following results were obtained for 239Pu: L total X-rays = (4.67±0.05)× 10 −2, K α X-rays = (1.219±0.009) × 10 −4, 38.7 keV γ-ray = (1.044±0.013) × 10 −4 and 129.3 keV γ-ray = (6.31±0.03) × 10 −5.