AUTHOR=Salvat Francesc , Quesada José Manuel 

TITLE=Collisions of Nucleons with Atoms: Calculated Cross Sections and Monte Carlo Simulation

JOURNAL=Frontiers in Physics

VOLUME=Volume 9 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2021.733949

DOI=10.3389/fphy.2021.733949

ISSN=2296-424X

ABSTRACT=After a summary description of the theory of elastic collisions of nucleons with atoms, we
present the calculation of a generic database of differential and integrated cross sections for the
simulation of multiple elastic collisions of protons and neutrons with kinetic energies larger than
100 keV. The relativistic plane-wave Born approximation, with binding and Coulomb-deflection
corrections, has been used to calculate a database of proton-impact ionization of K-shell and
L-, M-, and N-subshells of neutral atoms These databases cover the whole energy range of
interest for all the elements in the periodic system, from hydrogen to einsteinium ( Z = 1 –99);
they are provided as part of the PENH distribution package. The Monte Carlo code system PENH
for the simulation of coupled electron-photon-proton transport is extended to account for the
effect of the transport of neutrons (released in proton-induced nuclear reactions) in calculations
of dose distributions from proton beams. A simplified description of neutron transport, in which
neutron-induced nuclear reactions are described as a fractionally absorbing process, is shown to
give simulated depth-dose distributions in good agreement with those generated by the G EANT 4
code. The proton-impact ionization database, combined with the description of atomic relaxation
data and electron transport in PENELOPE , allows the simulation of proton-induced x-ray emission
spectra from targets with complex geometries.