Nucleon-induced reactions at intermediate energies: New data at 96 MeV and theoretical status

Double-differential cross sections for light charged particle production (up to A=4) were measured in 96 MeV neutron-induced reactions, at TSL laboratory cyclotron in Uppsala (Sweden). Measurements for three targets, Fe, Pb, and U, were performed using two independent devices, SCANDAL and MEDLEY. The data were recorded with low energy thresholds and for a wide angular range (20-160 degrees). The normalization procedure used to extract the cross sections is based on the np elastic scattering reaction that we measured and for which we present experimental results. A good control of the systematic uncertainties affecting the results is achieved. Calculations using the exciton model are reported. Two different theoretical approches proposed to improve its predictive power regarding the complex particle emission are tested. The capabilities of each approach is illustrated by comparison with the 96 MeV data that we measured, and with other experimental results available in the literature.Comment: 21 pages, 28 figure

Pre-equilibrium (exciton) model and the heavy-ion reactions with cluster emission

We bring the possibility to include the cluster emission into the statistical pre-equilibrium (exciton) model enlarged for considering also the heavy ion collisions. At this moment, the calculations have been done without treatment of angular momentum variables, but all the approach can be straightforwardly applied to heavy-ion reactions with cluster emission including the angular momentum variables. The direct motivation of this paper is a possibility of producing the superdeformed nuclei, which are easier to be detected in heavy-ion reactions than in those induced by light projectiles (nucleons, deuterons, $\alpha$-particles)

New method of pure 111In production by proton-induced nuclear reactions with enriched 112 Sn

We aimed at finding out a simple and reliable way of 111In production with the highest radionuclide purity from its grand parent 111Sb and parent 111Sn nuclei, produced by the 112Sn(p,2n)111Sb and 112Sn(p,pn)111Sn reactions, respectively. The target was a metallic 112Sn sample enriched to 84%. We have measured activation cross sections for seven reactions on an enriched 112Sn sample induced by 23.6 š 0.8 MeV energy protons. Gamma-ray spectroscopy with high-purity germanium detectors has been used. We also identified the activities of 55Co (T1/2 = 17.5 h) and 60Cu (T1/2 = 23.7 min) in proton beam monitoring Ni foils, induced in the natNi(p,X)55Co and natNi(p,X)60Cu reactions at 22.8 MeV proton energy. The cross sections determined for these reactions are: s[natNi(p,X)55Co] = 36.6 š 4 mb and s[natNi(p,X)60Cu] = 64.4 š 7 mb. The measured cross sections of reactions on tin isotopes are: sigma[112Sn(p,n)112Sb] = 4 š 0.8 mb; sigma[112Sn(p,2n)111Sb] = 182 š 26 mb; sigma[112Sn(p,pn)111Sn] = 307 š 35 mb; sigma[114Sn(p,2n)113Sb] = 442 š 52 mb; s[117Sn(p,n)117Sb] = 15 š 3 mb; sigma[117Sn(p,p’gamma)117mSn] = 0.37 š 0.06 mb; s[115Sn(p,2p)114m2In] = 0.01 š 0.002 mb. Our measurements indicated the expected yield of the 111In production to be 46 MBq/mAh (1.2 mCi/mi Ah). The contamination of 111In by the undesired nuclide 114m2In was determined and belongs to the smallest ones found in the literature. The measured cross sections were compared with theoretical calculations by two top-level nuclear reaction codes EMPIRE and TALYS

Exciton-model master equations and the spin mixing

Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Hidden states and hidden entropy

SIGLEITItal