Proton total reaction cross sections for [sup 42]Ca, [sup 44]Ca, and [sup 48]Ca between 21 and 48 MeV

Proton total reaction cross sections ([sigma][sub [ital R]]) have been measured for the nuclei [sup 42]Ca, [sup 44]Ca, and [sup 48]Ca at seven energies each between 20.8 and 48.0 MeV. The experimental results plus our previously measured [sigma][sub [ital R]] values for [sup 40]Ca are compared to the results of optical model analyses, both nonrelativistic and relativistic, of an extensive set of elastic scattering data for the same calcium isotopes in this energy range. The experimental results are also compared to global optical model predictions. In general, the theoretical values are in good agreement with the experimental results, with a slight preference for the relativistic analysis. In addition, our results are used in nuclear transparency calculations, which show that over the range of energies studied, the average nuclear transparency decreases by almost 15%.