Isotopically resolved neutron total cross sections at intermediate energies

Abstract

The neutron total cross sections σtot of 16,18 O, 58,64 Ni, 103 Rh, and 112,124 Sn have been measured at the Los Alamos Neutron Science Center (LANSCE) from low to intermediate energies (3 ≤ E lab ≤ 450 MeV) by leveraging waveform-digitizer technology. The σtot relative differences between isotopes are presented, revealing additional information about the isovector components needed for an accurate optical-model (OM) description away from stability. Digitizer-enabled σtot-measurement techniques are discussed and a series of uncertainty-quantified dispersive optical model (DOM) analyses using these new data is presented, validating the use of the DOM for modeling light systems ( 16,18 O) and systems with open neutron shells ( 58,64 Ni and 112,124 Sn). The valence-nucleon spectroscopic factors extracted for each isotope reaffirm the usefulness of high-energy proton reaction cross sections for characterizing depletion from the mean-field expectation.