Vay current deposition (#1051)

* Added stub for current correction in RZ spectral solver

* Start implementation of Vay deposition

* Continue implementation of Vay deposition

* Correct deposition of D

* Add phase shift for staggered currents

* Small clean-up

* Fix units in deposition of D

* Implement average of cumulative sum (needs bug fix)

* Start fixing bug in average of cumulative sum

* Still debugging

* Cumulative sums should be correct now

* Subtract averages of cumulative sums:

- current implementation: cumulative sums, inverse Fourier transform, subtraction of averages
- needs to be tested (including units of D after Vay deposition)
- needs to be shortened (too many loops over boxes and ParallelFors)

* [skip CI] Clean up and fix units

* Still fixing units

* [skip CI] Remove temporarily averages of cumulative sums

* [skip CI] Remove distinction between staggered and nodal

* Vay and Esirkepov similar results on periodic single box:

TODO:
- debug (charge not conserved);
- try using compute_shifted_shape_factor as in Esirkepov deposition;
- clean up;
- try on multiple boxes and with correction of mode at 0 frequency.

* [skip CI] Clean up

* Fix bug in 3D deposition

* [skip CI] Clean up

* Fix 2D and 3D implementation:

- simulation results agree between direct and Vay deposition in both 2D and 3D
- Travis CI tests should pass except for check of charge conservation (debug)

* Small clean-up

* Fix bug when compiling in RZ geometry

* Add benchmark json files (will be reset later)

* Do not set zero current at zero frequency

* [skip CI] Revert last commit and clean up

* Fix small bug after reverting commit

* Set nodal test first on Travis

* Fix benchmark for nodal test in 3D

* Fix particle output for nodal test in 3D

* Fix bugs due to staggering

* Rename current nodal Travis tests

* Add Travis tests staggered in 2D and 3D

* Further clean-up after bug fix

* Abort when using Vay deposition with domain decomposition

* Add optional argument of index type to forward FFT

* Fourier shifts can be private members as before

* Small clean-up

* Clean up and improve Doxygen documentation

* Fix small bug in analysis script for 2D tests

* Fix tests (remove E and B fields from particle diags)

* Add option to fill guard cells and docs

* Fix value of last guard cell by enforcing periodicity

* Revert changes merged from #1121

* Clean up style

* Improve docs

* Fix forgotten alignment

* Improve docs

* Make base class functions VayDeposition pure

Co-authored-by: Dave Grote <dpgrote@lbl.gov>

1 files changed, 20 insertions, 6 deletions

diff --git a/Source/Evolve/WarpXEvolve.cpp b/Source/Evolve/WarpXEvolve.cpp
index 674680773..fda7100d4 100644
--- a/Source/Evolve/WarpXEvolve.cpp
+++ b/Source/Evolve/WarpXEvolve.cpp
@@ -296,6 +296,9 @@ WarpX::OneStep_nosub (Real cur_time)
     if ( !fft_periodic_single_box && current_correction )
         amrex::Abort("\nCurrent correction does not guarantee charge conservation with local FFTs over guard cells:\n"
                      "set psatd.periodic_single_box_fft=1 too, in order to guarantee charge conservation");
+    if ( !fft_periodic_single_box && (WarpX::current_deposition_algo == CurrentDepositionAlgo::Vay) )
+        amrex::Abort("\nVay current deposition does not guarantee charge conservation with local FFTs over guard cells:\n"
+                     "set psatd.periodic_single_box_fft=1 too, in order to guarantee charge conservation");
 #endif
 
 #ifdef WARPX_QED
@@ -310,6 +313,8 @@ WarpX::OneStep_nosub (Real cur_time)
 // without guard cells, apply this after calling SyncCurrent
 #ifdef WARPX_USE_PSATD
     if ( fft_periodic_single_box && current_correction ) CurrentCorrection();
+    if ( fft_periodic_single_box && (WarpX::current_deposition_algo == CurrentDepositionAlgo::Vay) )
+        VayDeposition();
 #endif
 
 
@@ -792,19 +797,28 @@ WarpX::applyMirrors(Real time){
     }
 }
 
+// Apply current correction in Fourier space
 #ifdef WARPX_USE_PSATD
 void
 WarpX::CurrentCorrection ()
 {
     for ( int lev = 0; lev <= finest_level; ++lev )
     {
-        // Apply correction on fine patch
         spectral_solver_fp[lev]->CurrentCorrection( current_fp[lev], rho_fp[lev] );
-        if ( spectral_solver_cp[lev] )
-        {
-            // Apply correction on coarse patch
-            spectral_solver_cp[lev]->CurrentCorrection( current_cp[lev], rho_cp[lev] );
-        }
+        if ( spectral_solver_cp[lev] ) spectral_solver_cp[lev]->CurrentCorrection( current_cp[lev], rho_cp[lev] );
+    }
+}
+#endif
+
+// Compute current from Vay deposition in Fourier space
+#ifdef WARPX_USE_PSATD
+void
+WarpX::VayDeposition ()
+{
+    for (int lev = 0; lev <= finest_level; ++lev)
+    {
+        spectral_solver_fp[lev]->VayDeposition(current_fp[lev]);
+        if (spectral_solver_cp[lev]) spectral_solver_cp[lev]->VayDeposition(current_cp[lev]);
     }
 }
 #endif