Charged Particle Range
Published 2014 · Physics
This chapter considers one of the main manifestations of charged particle energy loss that of the penetration into matter. It begins with the derivation of the continuous slowing down approximation (CSDA) range for heavy charged particles and presents the Bragg peak. As electrons remain currently the most commonly used charged particles in radiation oncology, we review the depth–dose curves of electrons in soft tissue. Unlike energetic heavy charged particles, multiple Coulomb scatter is a significant effect upon the radiation transport of electrons and cannot be excluded in the determination of the range, as has already been examined in the context of the Fermi–Eyges theory of Sect. 6.3.7. We conclude the chapter with an examination of the ranges of positrons in matter and the probabilities of in-flight annihilation.