Experimental Determination of the Resonance Integral for ²³⁷Np in a Heavy Water Solution

Experimental determination of the resonance neutron absorption in a heavy water solution of 2.57 g/litre ²³⁷Np is presented. Experimental samples were irradiated in the MAKET critical plant. Prior to irradiation, ²³⁷Np was radiochemically purified to remove ²³³Pa. The experimental samples were prepared by evaporating two aliquot samples taken from the irradiated solution. The nuclide composition of the samples was analyzed using a GC-2518 Ge detector, a 1510 module, and an S-100 plate to emulate a multichannel analyzer in an IBM personal computer. The spectrometric resolution was 1.8 keV at the 1332-keV line. The gamma spectra were processed by the ASPRO code. The neutron flux was measured by two methods using Al + ⁵⁵Mn + ^natCu + ¹⁹⁷Au + ^natLu alloy foils.