Evidence for an absorption effect in neutron emission in the20Ne +58Ni reaction at 30 MeV per nucleon

Zeitschrift für Physik A Atomic Nuclei - Tập 335 Số 1 - Trang 77-85 - 1990
Cheynis, B.1, Chambon, B.1, Drain, D.1, Pastor, C.1, Heuer, D.2, Dauchy, A.2, Giorni, A.2, Morand, C.2, Stassi, P.2
1Institut de Physique Nucléaire de Lyon, CNRS Université Claude Bernard, Villeurbanne, France
2Institut des Sciences Nucléaires de Grenoble, CNRS, Université Joseph Fourier, Grenoble, France

Tóm tắt

Neutron energy spectra were analysed at various angles in coincidence with projectile-like fragments in the reaction20Ne +58Ni at 30 MeV per nucleon. The data have been parametrized with a three moving source fit, taking into account the emission from discrete excited states of the coincident light fragments and the recoil effect due to the emission of neutrons by light nuclei. A nucleon-nucleon scattering description of the intermediate velocity source gives good fits to the data. However the necessity of introducing a reabsorption effect in the projectile-like and target-like nuclei for the nucleons from that source is demonstrated by testing the momentum and energy balances in the fitting procedure. The mean free path of nucleons in nuclear matter is determined. A good agreement is then obtained for the lowest momentum transfers where single scattering dominates. For the largest momentum transfer another mechanism such as double scattering or one-body friction must be introduced in order to reproduce the data.

Tài liệu tham khảo

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