Determination of α in the Cadmium Lined Irradiation Channel of the NIRR-1 for Use in <i>k<sub>o</sub></i>-ENAA

Abstract

The epithermal neutron shape factor (α) was determined in the permanent cadmium lined irradiation channel installed in the large outer irradiation site of the Nigeria Research Reactor-1 (NIRR-1) by the cadmium covered multimonitor method using the monitors Al-0.1% Au, Zr and Zn thin foils and Mo thin wire and was found to be −0.137 ± 0.018. The high negative value of α indicates a hardened epithermal neutron spectrum in the cadmium lined irradiation channel. The α value obtained was used in the single comparator method of ENAA (ko-ENAA) for the determination of the concentrations of elements in the standard reference material NIST 1515 Apple leaves using Al-0.1% Au thin foil as the single comparator. The concentrations of the elements Sm and Br were determined in the NIST 1515 Apple leaves because of their high Qo values and are in good agreement with the certified values.

Elemental Analysis of Some Nigerian Food Legumes by <i>k<sub>o</sub></i>-ENAA and INAA

“…The value of the epithermal neutron shape factor (α) in the Cd lined irradiation channel determined by the cadmium covered multimonitor method using the monitor set Al-0.1%Au, Zr and Zn thin foils and Mo thin wire is −0.137 ± 0.018. A detailed description of the method used for the determination of the epithermal neutron shape factor (α) is given elsewhere [2] [14].…”

“…It was commissioned in 2004 and has been standardized for instrumental neutron activation analysis (INAA) [1]. In order to extend its utilization for epithermal neutron activation analysis (ENAA) protocol, the cadmium (Cd) lined irradiation channel was installed in one of the large outer irradiation channels [2]. Prior to now, the NIRR-1 has been used for elemental analysis via the k o -standardization method based on the K o -IAEA software [3].…”