Irradiation-Induced Processes with Atomic Clusters and Nanoparticles

Abstract

This chapter gives an overview of theoretical and computational studies of physical phenomena manifesting themselves in photon, electron and ion collisions with atomic clusters and nanoparticles (NPs). The emphasis is made on ion and electron scattering as well as photoabsorption of metal NPs which are of current interest in application in cancer treatments with ionizing radiation. Although the number of reports on dose enhancement and radiosensitization due to metal NPs has been rapidly increasing during the past years, physical mechanisms of enhanced production of secondary electrons and reactive species due to sensitizing NPs are still a debated issue and require thorough investigation. In this chapter, we elucidate the essential role of collective electron excitations in the formation of electron emission spectra of metal clusters and NPs. These effects appear also in other types of nanoscale systems, such as carbon-based NPs. We also briefly overview a number of recent Monte Carlo-based studies devoted to the investigation of radiosensitization and dose enhancement effects for proton irradiation combined with metal NPs.