3rd-INCC

Ultra sensitive measurements of Th-232 in copper by RNAA

23 Sept 2011, 11:40

15m

Paladini (Città del Mare, Terrasini - Palermo - Sicily - Italy)

oral presentation Radioanalytical Chemistry and Nanoparticles Session 14

Speakers

Dr Andrea Salvini (Università di Pavia)Dr Massimiliano Clemenza (Università di Milano Bicocca)

Description

Copper, thanks to its low content in radioactive contaminations, is a material widely used for shields, holders and others objects close to sensitive parts of the detectors in many experiments on Rare Events Physics. This imply that tools able to reach sensitivity of the order of <10-12 g of contaminants / g of Copper are of crucial importance. A methodology based on Neutron Activation Analysis (NAA) has been developed to obtain an extremely high sensitivity in the analysis of 232Th in Copper samples. A detection limits of 5 x 10-13 g 232Th /g Cu have been achieved through the irradiation of 200 g of copper sample which subsequently was been radiochemical concentrated using Nitric Acids and then Actinide Resin from Eichrom Inc. Several elutions with various inorganic acids were done to concentrate the 232Th activation product (233Pa) from copper matrix and to also eliminate the radioactive background induced by the neutron bombardment to reach an higher sensitivity.