Simulate an electron shower

An electron shower simulation is a simulation to see the trajectories of electrons as they loose energy inside the sample. Currently, the trajectories are displayed as projections in the XY, YZ and XZ planes.

The setup of an electron shower simulation is very similar to an EPMA simulation. A wizard guides the user through the different parameters.


To launch the wizard, click on shower from the toolbar of pyPENELOPE’s desktop. The first step is to select a name for the simulation as well as an empty folder to save the simulation’s input and result files.

The following panels (microscope parameters, geometry and simulation parameters are identical to those for an EPMA simulation. For explanations regarding these parameters, please refer respectively to the Microscope parameters, Geometry and materials and Simulation parameters section of the Simple simulation of a substrate tutorial. Note that the simulation parameters are not critical for a shower simulation. The default values are always highly recommended.

Finally, the last panel is to select the number of trajectories to simulate. The panel gives also the option to track secondary electrons, i.e. electrons that are generated by interaction of the primary electrons. Please note that the number of trajectories correspond to the total of primary and secondary electrons (if selected). Typical number of trajectories is 150 for only primary electrons and between 300 to 500 if secondary electrons are tracked.

Running the simulation

The new shower simulation appears in the simulation tree. Click play to start the shower simulation. The simulation of a shower is typically under one minute. No progress is displayed in the status bar.


The electron trajectories are color-coded:

  • blue: absorbed within the sample
  • red: backscattered (electron exits from the same surface as it entered)
  • green: transmitted (electron exits from another surface as the one it entered)

Example of an electron shower.

Electron trajectories figures can be saved in different file formats (PNG, EPS, etc.).