View More View Less
  • 1 MTA-KFKI-Atomic Energy Research Institute H-1525 Budapest 114 P.O.Box 49 Hungary
  • | 2 University of Gent Laboratory of Analytical Chemistry, Institute for Nuclear Sciences Proeftuinstraat 86 B-9000 Gent Belgium
  • | 3 University of Gent Laboratory of Analytical Chemistry, Institute for Nuclear Sciences Proeftuinstraat 86 B-9000 Gent Belgium
  • | 4 SCK·CEN, Belgian Nuclear Research Centre Boeretang 200 B-2400 Mol Belgium
  • | 5 European Commission, Joint Research Centre Institute for Reference Materials and Measurements B-2440 Geel Belgium
Restricted access

Abstract  

The k0 and Q0 values for 94Zr(n,)95Zr(E = 724.2+756.7 keV) and 96Zr(n,)97Zr() 97mNb (E = 743.4 keV) were re-investigated. The aim was to further improve the reliability of the neutron spectrum characterization (f and monitoring) in k0-NAA, based on "bare monitor" methods with the use of these Zr radionuclides. So as to achieve this goal, experimental determinations were performed in three reactor centers: KFKI AEKI, Budapest (WWR-M reactor); INW, Gent (THETIS reactor); SCK·CEN, Mol (BR1 reactor). The results were: Q0(94Zr) = 5.306; Q0(96Zr) = 251.6; k0(95Zr, 724.2+756.7 keV) = 2.000E-4; k0(97Zr/97mNb, 743.4 keV) = 1.237E-5. This means that the newly evaluated k0-values are about 4.7% lower than the formerly reported ones. It is also emphasized that the 97Zr half-life is 16.74 hours, contrary to the 1% higher values usually reported.