Applying a static magnetic field in HybridPICSolver, recommended approach?

[harish-junjun]

I am working on the PIC Hall thruster example by @archermarx and modifying it into a HybridPICSolver setup following the WarpX documentation.
Most Hall thruster models treat the magnetic field as externally imposed and constant in time. In the HybridPICSolver, however, the magnetic field is evolved using Faraday’s law with substepping. What is the correct way to represent a physically static magnetic field in this framework? Is there a supported approach to keep B fixed while still using the hybrid solver, or does this require modifying the field update in the source?

[roelof-groenewald]

Hi @harish-junjun. Thank you for your question. I would think that the change to the initial magnetic field would be small, unless your system has relatively high beta. Is this the case in your simulations? If you are interested in only capturing electrostatic field response based on the electron pressure gradient (a Boltzmann-like setup) you might also consider using a custom electrostatic solver as is done in this example: https://github.com/BLAST-WarpX/warpx/blob/development/Examples/Physics_applications/capacitive_discharge/inputs_test_2d_background_mcc_picmi.py