Mean multiple scattering correction to the energy loss of heavy particles

Abstract

The mean increase in energy loss δT m due to multiple scattering of heavy particles is treated for thick absorbers. Using Molière's theory with the improvements by Nigam et al., the mean square and mean fourth power of the reduced scattering angle are calculated for all absorber materials, for incident energies larger than a few MeV, for energy losses up to 80% of the incident energy, and for circular detectors with angles of acceptance up to ±35°. A method is given for computing the mean energy correction δT m from the incident and outgoing energies, from the stopping power of the absorber, and from the detector angle of acceptance. A typical value for δT m of 650 keV is obtained for 40 MeV protons loosing 32 MeV in a gold absorber and seen under a detector angle of ±29°.