Total (p, n) reaction cross-section measurements on ⁵⁰Ti, ⁵⁴Cr, and ⁵⁹Co

Abstract

The total (p, n) reaction cross sections, integrated over the 4Π solid angle and summed over all neutron groups, for ⁵⁰Ti, ⁵⁴Cr, and ⁵⁹Co have been measured as a function of proton energy in the energy range 3.0-4.9, 2.2-5.2, and 2.0-5.1 MeV in 5 keV steps, respectively. No strong isobaric analog resonances were seen in the data. The fluctuations in the excitation functions were analyzed to extract <Γ>_av values using the "counting of maxima" method. The excitation functions, averaged over 100 keV energy interval reveal prominent intermediate width structures in the case of ⁵⁰Ti. All the three excitation functions were averaged over suitable energy intervals and compared with the total reaction cross sections calculated utilizing the optical model. The data on ⁵⁹Co and ⁵⁴Cr agreed, while the data on ⁵⁰Ti indicated a marked discrepancy with these optical model calculations. In the latter case, detailed Hauser-Feshbach (HF) and Hauser-Feshbach-Moldauer (HFM) calculations were carried out. The HFM calculations fit the data quite well. The importance of σ(p, n) measurements in determining the imaginary potential of the optical model at sub-Coulomb energies has been indicated.