Excitation

The Excitation section allows the user to assign a current excitation source onto geometry. Addtionally, the Excitation section of CHARGE allows you to add a particle flux source for internal or coupled charging simulations. This source is capable of being incorporated in the FEM solver of CHARGE allowing for the particle transport source code to simulate its interaction with matter. The types of particles used in CHARGE by this feature are electrons, positron, alpha, photon, proton, neutron, and ions. The source can be defined to be active for the entire simulation or just a portion. Multiple particle sources can be added to allow the user freedom to create the total environment they desire and allow for multi-species interactions.

CHARGE uses either a spectrum.dat file to define the particle flux, and also has the ability to convert a previous STK file from the user into a format used by CHARGE. CHARGE does not yet allow the user to create the spectrum.dat file in the GUI, and the user must export a default file that is then modified via Notepad, Notepad++ etc. and then loaded into the GUI. To do this, the user must first set the material properties and then mesh the model to export the files.

If the user is planning on using the CHARGE designated spectrum.dat file, you will need to define the Materials, and Boundary Conditions if applicable, followed by the Meshing section to mesh the model. Once you have done that you can come back to the 'Spectrum File' portion of the manual to create it.

If the user wants to convert a previously made STK file into CHARGE format, go to the 'STK File' section to see how to load that into the GUI.