A method to deal with correlations affecting γ counting efficiencies in analytical chemistry measurements performed by k0-NAA. (23rd April 2020)

• Record Type: Journal Article
• Authors: Di Luzio, M; D'Agostino, G; Oddone, M
• Is Part Of: Measurement science & technology. Volume 31:Number 7(2020)
• Publication Date: 2020-04-23
• Subjects: correlations -- γ counting efficiency -- uncertainty -- neutron activation analysis -- k0 standardization; Physical measurements -- Periodicals; Scientific apparatus and instruments -- Periodicals; Equipment and Supplies -- Periodicals; Science -- instrumentation -- Periodicals; Technology -- instrumentation -- Periodicals; Mesures physiques -- Périodiques; Physical measurements; Scientific apparatus and instruments; Periodicals; 502.87
• DOI: 10.1088/1361-6501/ab7ca8
• Languages: English
• ISSNs: 0957-0233

Abstract

Abstract: The ratio of γ counting efficiencies is very important in trace element analysis carried out by prompt- and delayed- γ neutron activation based on k 0 standardization. Although the effect of correlation between counting efficiencies is well known and methods have been developed and adopted in prompt- γ neutron activation analysis to correctly evaluate the uncertainty, proposals and applications in delayed- γ neutron activation analysis are still lacking. To fill the gap, we developed a new method based on the use of reference γ -sources to determine the detection efficiency ratio and its uncertainty by taking full account of correlations. A measurement model that differs to some extent from the classical k 0 formulation widely used in delayed- γ neutron activation analysis is required. A detection system was characterized to test the suitability of the method in a double-counting position setup, where the standard is placed far from the detector end-cap and the sample is placed close to it. The present paper is a significant expansion of a relevant abstract presented at the 'Mathematical and Statistical Methods for Metrology' Workshop, Torino, Italy, 30–31 May 2019 (pp 27–28 in www.msmm2019.polito.it/programme ).