Include `J` in diagnostic output when an electromagnetic solver is not used (#4116)

* include current density in diagnostic output even if an electromagnetic solver is not used

* do not redeposit current for the magnetostatic solver

* update CI benchmarks for tests that previously did not register current density

* fix remaining failing CI test

* Apply suggestions from code review

Co-authored-by: Edoardo Zoni <59625522+EZoni@users.noreply.github.com>

* do not output current density in collision tests

* update `JFunctor` constructor doc-string

* code cleanup - reduce code duplication

* specify `Ex Ey Ez Bx By Bz` fields to plot for collision CI tests

* specify `Er Et Ez Br Bt Bz` as output for rz collision test

* rename `InterpolateToDst` to `InterpolateMFForDiag`

* only deposit current density once per diagnostic output (if not already deposited)

* write deposited current for all directions into `current_fp` during diagnostic step deposition

* use `amrex::make_alias` to directly deposit current density into `warpx.current_fp` during diagnostic step deposition

* add class variable `solver_deposits_current` to `FullDiagnostics` so that there is only one place where the determination is made whether current should be deposited during diagnostic output

* correct logic to determine `m_solver_deposits_current`

---------

Co-authored-by: Edoardo Zoni <59625522+EZoni@users.noreply.github.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/Source/Diagnostics/FullDiagnostics.H b/Source/Diagnostics/FullDiagnostics.H
index a20b44397..4bb3e2789 100644
--- a/Source/Diagnostics/FullDiagnostics.H
+++ b/Source/Diagnostics/FullDiagnostics.H
@@ -22,6 +22,10 @@ private:
     bool m_plot_raw_fields_guards = false;
     /** Whether to dump the RZ modes */
     bool m_dump_rz_modes = false;
+    /** Whether the field solver deposits current density, if not it will be done
+     * before writing the diagnostic.
+     */
+    bool m_solver_deposits_current = true;
     /** Flush m_mf_output and particles to file for the i^th buffer */
     void Flush (int i_buffer) override;
     /** Flush raw data */