Quality assurance of temporal variability of natural decay chain and neutron induced background for low-level NORM analysis
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Twenty-one high purity germanium (HPGe) background spectra were collected over 2 years at Los Alamos National Laboratory. A quality assurance methodology was developed to monitor spectral background levels from thermal and fast neutron flux levels and naturally occurring radioactive material decay series radionuclides. 238U decay products above 222Rn demonstrated minimal temporal variability beyond that expected from counting statistics. 238U and 232Th progeny below Rn gas displayed at most twice the expected variability. Further, an analysis of the 139 keV 74Ge(n, γ) and 691 keV 72Ge(n, n′) spectral features demonstrated temporal stability for both thermal and fast neutron fluxes.
KeywordsNORM Neutron Background Quality assurance HPGe
This material is based upon work supported by the U.S. Department of Homeland Security under Grant Award Number, 2012-DN-130-NF0001. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security.
- 8.Seifert A, Hensley WK, Siciliano ER, Pitts WK (2007) Fast neutron sensitivity with HPGe. In: Nuclear science symposium conference record 2007. NSS' 07. IEEE, Oct. 26 2007–Nov. 3 2007, pp 1175–1180Google Scholar
- 9.Press WH (2007) Numerical recipes 3rd edition: the art of scientific computing. Cambridge University Press, CambridgeGoogle Scholar
- 10.Donaldson TS (1966) Power of the F-test for nonnormal distributions and unequal error variances. Rand Corporation, New yorkGoogle Scholar
- 15.Meierhofer G, Grabmayr P, Jochum J, Kudejova P, Canella L, Jolie J (2010) Thermal neutron capture cross section of 74Ge. Phys Rev C 81. doi: 10.1103/PhysRevC.81.027603