title: Limitations (and merits) of PENELOPE as a track-structure code.
abstract: OBJECTIVE
  To outline the limitations of PENELOPE (acronym of PENetration and Energy LOss of Positrons and Electrons) as a track-structure code, and to comment on modifications that enable its fruitful use in certain microdosimetry and nanodosimetry applications.
  
  
  METHODS
  Attention is paid to the way in which inelastic collisions of electrons are modelled and to the ensuing implications for microdosimetry analysis.
  
  
  RESULTS
  Inelastic mean free paths and collision stopping powers calculated with PENELOPE and two well-known optical-data models are compared. An ad hoc modification of PENELOPE is summarized where ionization and excitation of liquid water by electron impact is simulated using tables of realistic differential and total cross sections.
  
  
  CONCLUSIONS
  PENELOPE can be employed advantageously in some track-structure applications provided that the default model for inelastic interactions of electrons is replaced by suitable tables of differential and total cross sections.
authors.affiliation: Facultat de Física (ECM and ICC), Universitat de Barcelona, Barcelona, Spain. jose@ecm.ub.es
authors.forename: José M
authors.initials: JM
authors.lastname: Fernández-Varea
authors.forename: Gloria
authors.initials: G
authors.lastname: González-Muñoz
authors.forename: Mariel E
authors.initials: ME
authors.lastname: Galassi
authors.forename: Kristin
authors.initials: K
authors.lastname: Wiklund
authors.forename: Bengt K
authors.initials: BK
authors.lastname: Lind
authors.forename: Anders
authors.initials: A
authors.lastname: Ahnesjö
authors.forename: Nina
authors.initials: N
authors.lastname: Tilly
mesh_terms: D004548:Elasticity; D004583:Electrons; D009010:Monte Carlo Method; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water