Differential elastic cross sections for protons between 10 and 22 MeV on Ca40

The differential elastic cross sections for protons on Ca40 have been obtained at energies between 9.8 and 21.7 MeV. A mass-identification system using an E+ΔE detector was employed for the measurements. Relative uncertainties are approximately ±2%. Absolute uncertainties are approximately ±5%. An optical-model analysis of these data and the available polarization data in the same energy region have been performed. Reasonable fits were obtained by analyzing the data above and below 16.6 MeV separately. Significant differences in the imaginary and spin-orbit potentials were observed in these two regions.