A new Am-Be PGNAA setup for element determination in aqueous solution

Ling Yongsheng; Jia Wenbao; Hei Daqian; Shan Qing; Cheng Can; Zhang Haojia; Hou Wenyu; He Yanquan; Chen Da

doi:10.1016/j.apradiso.2014.11.005

A new Am-Be PGNAA setup for element determination in aqueous solution

Appl Radiat Isot. 2015 Jan:95:233-238. doi: 10.1016/j.apradiso.2014.11.005. Epub 2014 Nov 12.

Authors

Ling Yongsheng¹, Jia Wenbao², Hei Daqian³, Shan Qing³, Cheng Can³, Zhang Haojia³, Hou Wenyu³, He Yanquan³, Chen Da³

Affiliations

¹ Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou 215021, China.
² Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou 215021, China. Electronic address: jia_wenbao@hotmail.com.
³ Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China.

PMID: 25464204
DOI: 10.1016/j.apradiso.2014.11.005

Abstract

A new prompt-gamma neutron activation analysis (PGNAA) setup has been designed for element determination in aqueous solution with a 300 mCi ²⁴¹Am-Be neutron source and a 4in.×3in. (diameter×height) BGO detector, uncooled. A polyethylene cylindrical sample container approximately 40cm in outer radius and 80cm in height was used. To reduce the neutron dose in the detector, a block of 5cm thickness Li₂CO₃ was placed between the source and the detector for separation, but no gamma-blocker was used. By adjusting the position of the detector and optimizing the geometrical conditions of the setup, the element detection limit with a low activity neutron source was further improved. This methodology was checked by simulations with chlorine, mercury and cadmium determination and by experiments with chlorine determination in aqueous samples. The results show a good linear relationship between chlorine concentration and the count of its characteristic peak, and the detection limit of chlorine can reach 41.7mg/L with a collection time of 3600s for each spectrum. Additionally, a linear relationship was identified between mercury concentration and the count of its characteristic peak, but for cadmium, a non-linear relationship was observed in the simulations.

Keywords: Detection limit; MOCA code; Prompt gamma neutron activation analysis.