title: Deceleration processes of secondary electrons produced by a high-energy Auger electron in a biological context.
abstract: To simulate the deceleration processes of secondary electrons produced by a high-energy Auger electron in water, and particularly to focus on the spatial and temporal distributions of the secondary electron and the collision events (e.g. ionization, electronic excitation, and dissociative electron attachment) that are involved in the multiplication of lesions at sites of DNA damage.
  
  
  
  We developed a dynamic Monte Carlo code that considers the Coulombic force between an ejected electron and its parent cation produced by the Auger electron in water. Thus our code can simulate some return electrons to the parent cations. Using the code, we calculated to within the order of femtoseconds the temporal evolution of collision events, the mean energy, and the mean traveling distance (including its spatial probability distribution) of the electron at an ejected energy of 20 eV.
  
  
  
  Some of the decelerating electrons in water in the Coulombic field were attracted to the ionized atoms (cations) by the Coulombic force within hundreds of femtoseconds, although the force did not significantly enhance the number of ionization, electronic excitation, and dissociative electron attachment collision events leading to water radiolysis.
  
  
  
  The secondary electrons are decelerated in water by the Coulombic force and recombined to the ionized atoms (cations). Furthermore, the some return electrons might be prehydrated in water layer near the parent cation in DNA if the electrons might be emitted from the DNA. The prehydrated electron originated from the return electron might play a significant role in inducing DNA damage.
authors.affiliation: a Nuclear Science and Engineering Center , Japan Atomic Energy Agency , Tokai , Naka , Ibaraki , Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kai
authors.affiliation: b Quantum Beam Science Center , Japan Atomic Energy Agency , Tokai , Naka , Ibaraki , Japan.
authors.forename: Akinari
authors.initials: A
authors.lastname: Yokoya
authors.affiliation: c Department of Applied Physics , Tokyo University of Agriculture and Technology , Koganei-shi , Tokyo Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ukai
authors.affiliation: b Quantum Beam Science Center , Japan Atomic Energy Agency , Tokai , Naka , Ibaraki , Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Fujii
authors.affiliation: b Quantum Beam Science Center , Japan Atomic Energy Agency , Tokai , Naka , Ibaraki , Japan.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Watanabe
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D004583:Electrons; D004735:Energy Transfer / Q000528:radiation effects*; D008954:Models, Biological; D008956:Models, Chemical; D015233:Models, Statistical; D009010:Monte Carlo Method; D011829:Radiation Dosage
chemical_list: D004247:DNA
keywords: Clustered DNA damage; dissociative electron transfer; dynamic Monte Carlo method; electron deceleration in water; prehydration; thermalization