title: Double differential cross sections for proton induced electron emission from molecular analogues of DNA constituents for energies in the Bragg peak region.
abstract: For track structure simulations in the Bragg peak region, measured electron emission cross sections of DNA constituents are required as input for developing parameterized model functions representing the scattering probabilities. In the present work, double differential cross sections were measured for the electron emission from vapor-phase pyrimidine, tetrahydrofuran, and trimethyl phosphate that are structural analogues to the base, the sugar, and the phosphate residue of the DNA, respectively. The range of proton energies was from 75 keV to 135 keV, the angles ranged from 15° to 135°, and the electron energies were measured from 10 eV to 200 eV. Single differential and total electron emission cross sections are derived by integration over angle and electron energy and compared to the semi-empirical Hansen-Kocbach-Stolterfoht (HKS) model and a quantum mechanical calculation employing the first Born approximation with corrected boundary conditions (CB1). The CB1 provides the best prediction of double and single differential cross section, while total cross sections can be fitted with semi-empirical models. The cross sections of the three samples are proportional to their total number of valence electrons.
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Rudek
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bennett
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Marion U
authors.initials: MU
authors.lastname: Bug
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Mingjie
authors.initials: M
authors.lastname: Wang
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Woon Yong
authors.initials: WY
authors.lastname: Baek
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Ticia
authors.initials: T
authors.lastname: Buhr
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Hilgers
authors.affiliation: Université de Bordeaux, CNRS/IN2P3, Centre d'Etudes Nucléaires de Bordeaux Gradignan, 33 175 Gradignan Cedex, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Champion
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Rabus
mesh_terms: D004247:DNA / Q000737:chemistry*; D004583:Electrons; D005663:Furans / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D010755:Organophosphates / Q000737:chemistry; D011522:Protons; D011743:Pyrimidines / Q000737:chemistry; D014835:Volatilization
chemical_list: D005663:Furans; D010755:Organophosphates; D011522:Protons; D011743:Pyrimidines; C018674:tetrahydrofuran; D004247:DNA; C030986:pyrimidine; C003715:trimethyl phosphate