Une Etude du Desaccord Entre les Valeurs Calculee et Mesuree de l'Integrale Effective de l'Uranium 238

摘要

Up to now, there was a discrepancy between the computed value and the measured value of the uranium 238 effective capture integral. The former has been always greater than the latter. For this reason, the reactor physicists have used an adjustement of the computed value. Nowadays the accuracy of the cross section knowledge is increased and the reactor computation codes are almost exact. Such an adjustment is no more justified. Recently several new measurements of the resonance parameters were carried out and the use of a multilevel formalism was suggested to compute the uranium 238 cross sections. It is shown in this work that the simultaneous use of recent parameters and Reich and Moore formalism explain the discrepancy. For the thermal neutron reactors, two thirds of this discrepancy are explained by the neutron data and the last third by the multilevel formalism. (Atomindex citation 10:494900)