Cross Section Measurements of (n,x) Reactions at 17.9 and 18.9 MeV Using Highly Enriched Ge Isotopes

Nine neutron induced reactions on Ge isotopes ( 70 Ge(n,2n) 69 Ge, 76 Ge(n,2n) 75 Ge, 73 Ge(n,p) 73 Ga, 72 Ge(n,p) 72 Ga, 73 Ge(n,d/np) 72 Ga, 74 Ge(n,d/np) 73 Ga, 74 Ge(n,α) 71m Zn, 72 Ge(n,α) 69m Zn, 73 Ge(n,nα) 69m Zn) have been measured in this work at energies 16.4-18.9 MeV. For these reactions, most of the experimental datasets in literature were obtained with a nat Ge target. However, the residual nucleus produced by some reaction channels can also be produced from neighboring isotopes, acting as a contamination for the measured reactions. This contribution must be subtracted, based on theoretical calculations, bearing their own uncertainties. The use of enriched targets however, does not suffer from such contaminations, leading to accurate experimental results. In this scope, five highly isotopically enriched Ge samples have been used in this work. The quasi-monoenergetic neutron beams were produced via the 3 H(d,n) 4 He reaction at the 5.5 MV Tandem Van de Graaff accelerator of N.C.S.R. ‘Demokritos’. The cross section of these nine reactions were measured using the activation method, with respect to the 27 Al(n,α) 24 Na reference reaction.