Radiotherapy Proton Interactions in Matter

A survey of physics useful to proton radiotherapy, centered on stopping, scattering and hard scatters: 1. Introduction 2. The fundamental formula dose = fluence x mass stopping power. Practical units, comments on effective stopping power. 3. Range: experimental definition, Beth-Bloch CSDA theory, range-energy tables and approximations, range straggling. 4. Multiple Coulomb Scattering: suggested reading, elements of Moliere theory, the Gaussian approximation, scattering power. 5. Hard scatters (nuclear interactions): contributing reactions, shape and size of the halo, experiment, halo as a Monte Carlo test. 6. Bragg curve (effective stopping power): limiting cases S_em and S_mixed, transverse equilibrium, computing S_em, measuring S_mixed, parameterizing the nuclear halo. 7. Looking ahead: Fermi-Eyges theory, the Preston and Koehler rules, a proton dose algorithm from first principles. Appendices: A. Acronyms B. Symbols C. Gaussians D. Relativistic kinematics E. Simple design problems.