Using displacements.output, energy_loss.output and Other rustbca Output Files
Rustbca can track nuclear and electronic energy losses through [name]energy_loss.output spatially by using the track_energy_losses option in [options]. This data can be used as a visual aid, for example, to show the when nuclear or electronic interactions are dominant over the course of an ion trajectory. The figure below shows an example for H on Li, where the size of each circle corresponds to the nuclear energy loss at that location and the color of each circle corresponds to the electronic energy loss. It is obvious that large angles of deflection are associated with large nuclear energy transfer.
Additionally, 2D plots of energy losses can be made. Rustbca's geometry is 2D, but it does extend infinitely in z, so 3D data can be obtained for simple targets.
Additionally, through [name]displacements.output, enabled by setting track_displacements = true in [options], one can use the displacement energy to find all frenkel pairs created in the simulation:
Combining the results of all the output files of rustbca, one can plot the total effect of the ion-material interaction on the material - heating through electronic and nuclear stopping, displacement damage, and ion deposition.
Rustbca uses a static target, that is, the ion beam does not modify the target in a single simulation. However, cumulative effects of ion-material interactions such as sputtering causing changes to surface morphology can be modeled using repeated runs of rustbca allowing each simulation to converge (in the Monte Carlo sense) before proceeding to the next step. An example of such a usage would be to use the origin location of all sputtered atoms to find the distribution of locations from which atoms are sputtered to model surface morphology changes through removal of atoms by physical sputtering
Sputtered atoms are often just one or two effective monolayers below the surface.