A simple functional form for proton-nucleus total reaction cross   sections
  A simple functional form has been found that gives a good representation of the total reaction cross sections for the scattering of protons from (15) nuclei spanning the mass range ${}^{9}$Be to ${}^{238}$U and for proton energies ranging from 20 to 300 MeV. 
K. Amos and P. K. Deb