Comments on ICRU-49: Stopping Powers and Ranges for Protons and Alpha Particles

The international Commission on Radiation Units and Measurements (ICRU) published report #49 in 1993 on Stopping Powers and Ranges and Alpha Particles. Since the report does not discuss its accuracy, and shows only limited comparisons to experimental data, this Comment concerns estimates of the accuracy of its tables. Some of the stopping tabulations appear to have unusual variations for high energies (>1MeV/u) of the order of 2-4%, while the lower energies have possible errors of 10-20% for those targets which were not fitted with new data.