The Cu(n; 2n) Excitation Function and the Knock-out Process in Nuclear Reactions

The (n; 2n) excitation cross section in copper is calculated on the basis of the compound nucleus formalism. If the probability for the formation of the compound nucleus by the incident neutron is assumed to be equal to unity, the calculated cross section becomes much larger than the experimental one. When the knock-out process is taken into account and a smaller probability is adopted, the agreement with the experiment can be made better to some extent. The estimate of the cross section of the knock-out process is obtained by the use of a very simplified model.