Use the Particle-Matter Interactions node to model the propagation of energetic ions through solid material. The
Ionization Loss and
Nuclear Stopping subnodes are available from the context menu (right-click the parent node) or from the
Physics toolbar,
Attributes menu. In order to model the interaction of particles with the target material, at least one subnode must be added.
By default, the Density ρ (SI unit: kg/m
2) is taken
From material. For
User defined enter another value or expression.
Enter a value or expression for the Atomic mass A (SI unit: kg). The default value is
28.0855 amu, the relative atomic mass of silicon. Then enter a value or expression for the
Atomic number Zm (dimensionless). The default value is
14.
Enter a value or expression for the Atomic number Zp (dimensionless). The default value is 1. The particle atomic number is used to define screened Coulomb potentials for the
Nuclear Stopping node.
Select the Stop particles with energy below cutoff to cause particles to stop moving when their energy is less than a specified value. This check box is selected by default. Then enter a value or expression for the
Cutoff energy Ec (SI unit: J). The default value is
8.6 eV.
By default, all of these check boxes are cleared. If any of the three check boxes are selected, enter a value or expression for the Quality factor Q (dimensionless). This quality factor is used to convert between absorbed dose and dose equivalent, either of which can be plotted. The default is 1. If the model particles represent a heavy species such as protons or alpha particles, then a larger value of
Q should be entered.