Electron ejection by heavy particles as precursor of track formation in condensed matter
详细信息查看全文 | 推荐本文 |
摘要
The detailed knowledge of the structure of ion tracks is a key issue for our understanding of radiation effects in condensed matter. Important examples are the radial energy deposition profile by electronic excitation for numerical simulations of track formation (via “Coulomb explosion” or “thermal spike”) in inert matter, and calculations of the RBE (relative biological effectiveness) of heavy particles in living matter (with important applications in dosimetry and hadrontherapy). In both cases, differential electron ejection cross sections are used as input parameter. The precursor of track formation is thus electron ejection from target atoms, or from the projectile itself. These primary electrons and their subsequent secondary interactions lead to the deposition of energy along and around the ion trajectory. We first briefly discuss “primary ionization” (binary encounter and soft electron emission, multiple collision sequences: “Fermi shuttle”) common to single atoms (gas targets) and condensed matter. Then, specific effects in condensed matter (electron transport, jet-like electron spikes, wake effects due to collective excitation of plasmons and emission of shock wave electrons) will be presented. Finally, we concentrate on effects connected to the high density of deposited energy and strong perturbation induced by heavy particles such as heavy ions and clusters (reduction effects due to screening, transport and “sweeping away”, multiple ionization, electronic temperatures from Auger spectroscopy).

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700