A PRECISE MEASUREMENT OF THE RANGE OF 100-MEV PROTONS IN ALUMINIUM

Abstract
The range of 100-MeV protons in aluminium has been determined using the external beam of the McGill synchrocyclotron. The energy and range were determined for a finely collimated pencil beam with an energy spread of 0.12 MeV. Beam energy was measured by the floating-wire technique. Two range determinations yielded values of 9 840 ± 9 mg/cm2 at 99.88 ± 0.08 MeV and 9 768 ± 10 mg/cm2 at 99.58 ± 0.08 MeV. Range straggling was found to be in agreement with theory. The mean excitation potential in aluminium has been estimated from these results to be 156 ± 2 eV.