The application of track calculations to radiobiology. II. Calculations of microdosimetric quantities.

In this second paper of a series, Monte Carlo-simulated proton tracks in water vapor are analyzed to yield a range of quantities that are of radiobiological interest. These include proximity functions of energy deposition, lineal energy distributions in micrometer and nanometer site sizes, and radial energy distributions. Many of these quantities cannot be measured with current experimental techniques. Some results are compared with those from analytic calculations. Also the effect on such quantities of the uncertainties in cross-sectional data used in the original Monte Carlo calculations is assessed, as is the effect of including nonionizing energy-loss events for analysis in the calculation.