Electronic stopping power of diamond for electrons and positrons

Abstract

We assess a new data set of mass electronic stopping powers of diamond for electrons and positrons. To this end, an optical energy-loss function (OELF) for this material is generated from available experimental dielectric properties of the valence band and photoabsorption mass attenuation coefficients, supplemented with a Drude-type analytical expression to interpolate at intermediate energies. From this synthetic OELF, a mean excitation energy equal to (88.5 ± 2.0) eV is extracted and the density-effect correction is evaluated using Fano’s simplified method. These quantities then allow calculating the mass electronic stopping power of diamond for electrons and positrons by means of the relativistic Bethe formula. The present results for 1 keV–1 GeV electrons in diamond are 0.9%–3.3% smaller than those corresponding to graphite as tabulated in ICRU Report 90.

Energy loss of MeV protons in diamond: Stopping power and mean ionization energy

“…Since diamond is an allotropic form of carbon with strong atomic bonding and tightly-packed crystal structure, it may have a different excitation energy, expected to be somewhat higher than that of graphite [25]. In a recent paper, Fernández-Varea et al [41] estimated the I-value for diamond to be 88.5 eV, based on electron and positron stopping power data. However, the mean ionization potential calculated here is consistent with the previously reported results for graphite.…”