Is the PML wave condition available in 1D3V geometry?

[YifanWu-USTC]

Dear Warpx team,
I want to use an absorbing field condition in a 1D cartesian simulation, so I set:

boundary.field_lo = pml
boundary.field_hi = pml
boundary.particle_lo = Reflecting
boundary.particle_hi = Reflecting

and some guard cells with particles so reflecting particles does not mirror the wave back

warpx.do_pml_in_domain = 1
warpx.pml_has_particles = 1
warpx.do_pml_j_damping = 1

but running it will crash without very meaningful diagnostic messages.

If I remove the three lines about do_pml_in_domain/has_particles/j_damping,
it will simply report a clear error:
amrex::Abort::7::PML not implemented in 1D geometry !!!

A possible walk around is to use 2D coordinate with nx=1, where the pml can work fine.
However, it might be not as "elegant" or direct.

Therefore, my question is that: is the PML possible to be implemented for 1D geometry?
And: is PML planned to be implemented to 1D geometry?

[RemiLehe]

Hi @YifanWu-USTC

Thanks for your question.
You are correct that the PML is unavailable in 1D, but you can instead use the Silver-Mueller boundary condition, which should be near-optimal for 1D simulations:

boundary.field_lo = absorbing_silver_mueller
boundary.field_hi = absorbing_silver_mueller

(The Silver-Mueller boundary condition is less ideal for 2D and 3D simulations for waves in oblique incidence, and this is why one would use PML instead in those cases.)

[YifanWu-USTC]

Thank you very much for the kind explanation! I will try with Silver-Mueller boundary condition.