title: Configuration interaction calculations of cross sections for proton stopping reactions.
abstract: OBJECTIVE
  To illustrate the role of quantum mechanical electronic structure methods in providing accurate predictions of the cross sections for ionization and electron capture processes that occur as a result of proton collisions in the high-eV to low-keV energy region.
  
  
  METHODS
  Calculations are carried out to compute potential curves and non-adiabatic coupling elements for a variety of collision partners employing the ab initio multireference single- and double-excitation configuration interaction (MRD-CI) method. These results are used as input for the electronic-state close-coupling (ESCC) method in order to compute cross sections for various transitions that occur because of collisions.
  
  
  RESULTS
  Emphasis is placed on proton-molecule collisions that play a key role in various medical applications as well as in astrophysics and nano-scale materials manufacturing. Examples discussed include the Na-He pair of atoms of interest in recent astrophysical observations, proton collisions with various hydrocarbons and also with water and oxygen, and key ionic products such as H(2)O(+) and H(3)O(+) .
  
  
  CONCLUSIONS
  The computed cross sections provide a detailed picture of radiation damage dynamics in Monte Carlo simulations. This information can potentially enhance the efficiency of proton beam focusing and also reduce undesirable side effects on body tissues.
authors: Fachbereich C-Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Wuppertal, Germany. bobwtal@yahoo.de
authors: Robert J
authors: RJ
authors: Buenker
authors: Heinz-Peter
authors: HP
authors: Liebermann
authors: Mineo
authors: M
authors: Kimura
mesh_terms: D004583:Electrons; D006838:Hydrocarbons / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D011522:Protons; D011789:Quantum Theory; D014867:Water / Q000737:chemistry
chemical_list: D006838:Hydrocarbons; D011522:Protons; D014867:Water; D010100:Oxygen