search

ComputationalRadiationPhysics / picongpu

Performance-Portable Particle-in-Cell Simulations for the Exascale Era :sparkles:
https://picongpu.readthedocs.io
Other
689 stars 216 forks source link

FieldToParticleInterpolation: Smooth #2001

Open n01r opened 7 years ago

n01r commented 7 years ago

It seems that for certain setups the "noise" created by local electric fields of free electrons is enough to ionize atoms/ions in an unphysical way.

@ax3l proposed that smoothing the used FieldToParticleInterpolation to more physical scales between smallest resolved wavelength and cell size will reduce the numerical noise and produce results of better quality. (updated 2017-04-28)

This issue is relevant especially for solid density targets.

ax3l commented 7 years ago

Thanks for already opening an issue! :sparkles:

To be more precise, it's not about the Debye lengths but about smoothing to a scale between the cell size (arbitrary, non-physical, not necessarily in the order of the Debye length) and the smallest resolved wavelength.

In the case we are looking in (solid target) this is a smoothing to better account for the effects of plasma waves (while cutting their top amplitude a little) and reducing small ringing from few-cell noise.