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  • 1 Delft University of Technology Interfaculty Reactor Institute Delft The Netherlands
  • 2 Czechoslovak Academy of Sciences Nuclear Physics Institute Řež Czechoslovakia
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Abstract  

Profiles of thermal flux, epithermal flux, f and have been determined for a multisample irradiation container in use with k0-based NAA. It could be concluded that for accurate NAA with the IRI-reactor, samples should be surrounded by at least two thermal flux monitors. Since f and values were found to vary considerably between irradiations as compared to the variations within one container, the possibility of determining f and just once for the irradiation facility used, and monitoring only the thermal flux in future irradiations, was ruled out. The use of average values for f and within a container was shown to yield unacceptable inaccuracies mainly for Zr and U determinations.