Experimental determination of the resonance integral for Np-237 in a heavywater solution

Experimental determination of the resonance neutron absorption in a heavy w ater solution of 2.57 g/l Np-237 is presented. Experimental samples were ir radiated in the MAKET critical plant. Prior to irradiation, Np-237 was radi ochemically purified to remove Pa-233. The experimental samples were prepar ed by evaporating two aliquot samples taken from the irradiated solution. T he nuclide composition of the samples was analyzed using a GC-2518 Ge detec tor 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 neut ron flux was measured by two methods using Al + Mn-55 + Cu-nat + Au-197 + L u-nat alloy foils.