The Stopping Cross Section ofD2O Ice

The energy loss of protons and deuterons in ${\mathrm{D}}_2$O ice has been measured over the energy range $E_p=18-541\mathrm{}$ kev using the double focusing magnetic spectrometer to measure the energy of the particles after they have traversed a known thickness of the ice target. One method of measurement is used to determine relative values of the stopping cross section as a function of energy, another method measures the absolute values. The results are in very good agreement with the values calculated from Bethe's semi-empirical formula. Possible sources of error are considered and the accuracy of these measurements is estimated to be ±4 percent.