Thoughts about particle pusher #473
Description
As I am thinking about the further development of this package with a PIC model in mind, making the particle pusher part a standalone module is intriguing.
- For TestParticle.jl and PIC.jl, the particle pusher methods are shared. The difference is that in TestParticle.jl there would be no feedback from particles on the field, whereas in PIC.jl there is an extra field solver that needs particle information. Being it explicit or implicit, a generic particle pusher is always needed.
- Instead of creating a new package, we can simply come up with clean APIs from TestParticle.jl and utilize them directly in the PIC model.
- In the PIC model, by turning off the field update, we essentially fall back to the test particle model.