Boundary distort the field in refinement.

[jiecaix]

I'm using the refinement mesh in simulation, and i find some problem in it.

1. I set a small laser pulse at Level 1 region, and the field is indeed a good small laser pulse in level 1 region. But the level 0 field with the low frequency projection of level 1 laser field will gradually expand longer and longer and shift back.

Field of Level 0 at end of timestep

2. The level 1 window following a field look like Numerical Cherenkov radiation.

Field of Level 0 at end of timestep

3. Near the boundary of level 1, the FieldProbe module will probe a strong field compared to others region.

Field probe by FieldProbe

[ax3l]

@zhazhajust it is a bit hard to follow here, but you might want to post more details and try higher resolution and/or other field solvers.

There is also an option lasers.deposit_on_main_grid that you can try:
https://warpx.readthedocs.io/en/latest/usage/parameters.html#laser-initialization