Dear Fredrik,
Thank you for your reply. Back then, I chose to consider collisionless plasma to simplify the problem. However, I am now moving toward modeling collisional plasma. So, I appreciate your suggestion!
It turned out that my issue was due to an incorrect definition of the discharge channel surface in Gmsh. Once I fixed the surface definition, SPIS was able to import the thruster into my simulation.
Now, the question is how to change the thruster parameters (which, if I understand correctly, is still an open topic on this forum) and how to properly add collisions.
Sincerely,
Egor