DSMC and PICMC documentation

2.1 Species list

The list of species is included in rvmscripts/species_definition.r below your picmc installation directory. In this file, each species is defined in one lines and takes two parameters, the relative atomic mass and the charge in units of the elemental electric charge \(e \simeq 1.6022\times 10^{-19}\) As. The entries for Ar and Arplus e.g. are written as follows:

Record Ar         = GenSPEC + { mr =  39.948;  charge =  0.0; };
Record Arplus     = GenSPEC + { mr =  39.948;  charge = +1.0; };

If additional species are needed, which are not included in the predefined species list below, they can be created as follows:

• Copy the file .../rvmscripts/species_definition.r into the local directory, where also the *.par file etc. reside, and name it e.g.  my_species_definition.r
• Add the required species into that file
• Refer to this file from inside the *.par file as shown in section (sec:par_species_cross_sections?).
• Usually, it will then be also necessary to extend the list of available cross sections.

The file rvmscripts/species.r contains some routines to load the chosen species into the actual simulation run and treat them differently according to their charge, weight etc. - this file usually shouldn’t be modified.

All names of the predefined species are listed in the following.