Charged-particle transport in the condensed phase.
Traditionally, studies of the biological effects of ionizing radiation have rested on the triumvirate: (gas-phase) radiation physics, biophysical modeling, and radiation biology. Two technical developments, the advent of supercomputing as a routine tool in quantum solid-state material science and molecular dynamics on the one hand, and molecular biology on the other hand, have created--perhaps for the first time-the possibility of directly linking a more realistic description of the radiation field to observable events at biomolecular level. It also becomes increasingly clear that the identification of specific molecular targets imposes a challenge to the radiation physics community to be equally specific in treating the energy--deposition stage of radiation action. In this paper: a) I review--and exemplify with results from our own work--the current status in Monte Carlo simulation of gas-phase material (particle transport and stochastic chemistry); b) examine the link between these essentially geometric representations of the track and the concept of "spatial distribution of energy deposition," a staple in radiation modeling; c) advocate an effort towards developing conceptually and calculationally, the field of solid-state microdosimetry; and d) describe methods based on semi-empirical Hamiltonians or quasi-particle techniques for obtaining the frequency-dependent and wave-vector-dependent dielectric response function for biomolecular crystalline systems, which are the main ingredients for describing charged-particle transport.
Zaider
M
M
Center for Radiological Research, College of Physicians & Surgeons of Columbia University, New York.
D008433:Mathematics; D008962:Models, Theoretical; D009010:Monte Carlo Method; D011830:Radiation Effects; D011839:Radiation, Ionizing