TITLE:
Determination of α in the Cadmium Lined Irradiation Channel of the NIRR-1 for Use in ko-ENAA
AUTHORS:
F. T. Sheyin, M. O. A. Oladipo, S. A. Jonah, U. Sadiq
KEYWORDS:
α Value, Cadmium Covered Multimonitor Method, Cadmium Lined Irradiation Channel, ko-ENAA
JOURNAL NAME:
World Journal of Nuclear Science and Technology,
Vol.5 No.3,
July
31,
2015
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.