I'm not sure I can help you but COMSOL has plasma simulation module for Inductively or capacitively coupled plasma and also gas discharge I guess. If you plasma generation mechanism is typical, then COMSOL might be good for you.

Dr. Mark Kushner is an leading expert in this field.

check out his publication :

http://uigelz.eecs.umich.edu/publications.html

Plasimo code can be used for the modelling of non-thermal plasma. It is freeware and you can request to the concerned faculty for the use of that code. Check this website

https://plasimo.phys.tue.nl/

COMSOL also provides the facility of simulation for non-thermal plasmas using Finite element method, however, you need to buy a licence to use that code.

Before use of any code, make sure which technique you like to use, Finite difference method or Finite element method.