Move 1D deposition into a separate function.

Author: cemitch99

src/particles/spacecharge/CMakeLists.txt

@@ -4,6 +4,7 @@ target_sources(lib
     Gauss3dPush.cpp
     Gauss2p5dPush.cpp
     GatherAndPush.cpp
+    Deposit1D.cpp
     HandleSpacecharge.cpp
     PoissonSolve.cpp
 )

src/particles/spacecharge/Deposit1D.H

@@ -0,0 +1,44 @@
+/* Copyright 2022-2025 The Regents of the University of California, through Lawrence
+ *           Berkeley National Laboratory (subject to receipt of any required
+ *           approvals from the U.S. Dept. of Energy). All rights reserved.
+ *
+ * This file is part of ImpactX.
+ *
+ * Authors: Ji Qiang
+ * License: BSD-3-Clause-LBNL
+ */
+#ifndef IMPACT_DEPOSIT1D_PUSH_H
+#define IMPACT_DEPOSIT1D_PUSH_H
+
+#include "particles/ImpactXParticleContainer.H"
+
+#include <AMReX_REAL.H>
+
+
+namespace impactx::particles::spacecharge
+{
+    /** Deposit charge using longitudinal binning for the calculation of space charge
+     *
+     *  This function performs particle binning for particles in the beam along the
+     *  longitudinal direction, for the purposes of computing space charge in
+     *  so-called 2.5D models.
+     *
+     * @param[in] pc container of the particles that deposited rho
+     * @param[out] beam_profile deposited charge density
+     * @param[out] beam_profile_slope derivative of deposited charge density
+     * @param[in] bin_max location of lower endpoint for binning
+     * @param[in] bin_max location of upper endpoint for binning
+     * @param[in] num_bins number of longitudinal bins
+     */
+    void Deposit1D (
+        ImpactXParticleContainer & pc,
+        amrex::Real * beam_profile,
+        amrex::Real * beam_profile_slope,
+        amrex::Real bin_min,
+        amrex::Real bin_max,
+        int num_bins
+    );
+
+}  // namespace impactx::particles::spacecharge
+
+#endif // IMPACT_DEPOSIT1D_H

src/particles/spacecharge/Deposit1D.cpp

@@ -0,0 +1,68 @@
+/* Copyright 2022-2025 The Regents of the University of California, through Lawrence
+ *           Berkeley National Laboratory (subject to receipt of any required
+ *           approvals from the U.S. Dept. of Energy). All rights reserved.
+ *
+ * This file is part of ImpactX.
+ *
+ * Authors: Ji Qiang
+ * License: BSD-3-Clause-LBNL
+ */
+#include "Deposit1D.H"
+
+#include "diagnostics/ReducedBeamCharacteristics.H"
+#include "particles/wakefields/ChargeBinning.H"
+
+#include <AMReX_REAL.H>
+#include <AMReX_BLProfiler.H>
+#include <AMReX_GpuContainers.H>
+#include <AMReX_ParmParse.H>
+
+#include <cmath>
+
+
+namespace impactx::particles::spacecharge
+{
+
+    void Deposit1D (
+        ImpactXParticleContainer & pc,
+        amrex::Real * beam_profile,
+        amrex::Real * beam_profile_slope,
+        amrex::Real bin_min,
+        amrex::Real bin_max,
+        int num_bins
+    )
+    {
+        BL_PROFILE("impactx::spacecharge::Deposit1D");
+
+        using namespace amrex::literals;
+
+        amrex::ParticleReal const charge = pc.GetRefParticle().charge;
+
+        // Set parameters for charge deposition
+        bool const is_unity_particle_weight = false;
+        bool const GetNumberDensity = true;
+
+        amrex::Real const bin_size = (bin_max - bin_min) / (num_bins - 1);  // number of evaluation points
+        // Allocate memory for the charge profile
+        amrex::Gpu::DeviceVector<amrex::Real> charge_distribution(num_bins + 1, 0.0);
+        // Call charge deposition function
+        impactx::particles::wakefields::DepositCharge1D(pc, charge_distribution, bin_min, bin_size, is_unity_particle_weight);
+
+        // Sum up all partial charge histograms to each MPI process to calculate
+        // the global charge slope.
+        amrex::ParallelAllReduce::Sum(
+            charge_distribution.data(),
+            charge_distribution.size(),
+            amrex::ParallelDescriptor::Communicator()
+        );
+
+        // Call charge density derivative function
+        amrex::Gpu::DeviceVector<amrex::Real> slopes(charge_distribution.size() - 1, 0.0);
+        impactx::particles::wakefields::DerivativeCharge1D(charge_distribution, slopes, bin_size,GetNumberDensity);
+
+        beam_profile = charge_distribution.data();
+        beam_profile_slope = slopes.data();
+
+    }
+
+}  // namespace impactx::particles::spacecharge

src/particles/spacecharge/GatherAndPush.cpp

@@ -11,6 +11,7 @@
 
 #include "initialization/Algorithms.H"
 #include "particles/wakefields/ChargeBinning.H"
+#include "particles/spacecharge/Deposit1D.H"
 
 #include <ablastr/particles/NodalFieldGather.H>
 
@@ -37,6 +38,23 @@ namespace impactx::particles::spacecharge
 
         amrex::ParticleReal const charge = pc.GetRefParticle().charge;
 
+        // Deposit 1D charge density in cases where it is required.
+        amrex::Real * beam_profile = nullptr;
+        amrex::Real * beam_profile_slope = nullptr;
+        int num_bins = 129;
+
+        [[maybe_unused]] auto const [x_min, y_min, t_min, x_max, y_max, t_max] =
+            pc.MinAndMaxPositions();
+
+        amrex::Real bin_min = t_min; 
+        amrex::Real bin_max = t_max;
+        amrex::Real const bin_size = (bin_max - bin_min) / (num_bins - 1);
+
+        if (space_charge == SpaceChargeAlgo::True_2p5D) {
+
+            Deposit1D ( pc, beam_profile, beam_profile_slope, bin_min, bin_max, num_bins);
+        }
+
         // loop over refinement levels
         int const nLevel = pc.finestLevel();
         for (int lev = 0; lev <= nLevel; ++lev)
@@ -120,43 +138,6 @@ namespace impactx::particles::spacecharge
                     auto prob_lo_2D = gm.ProbLoArray();
                     prob_lo_2D[2] = 0.0_rt;
 
-                    // Calculate z-dependent scaling by current
-                    int tp5d_bins = 129;
-                    amrex::ParmParse pp_algo("algo.space_charge");
-                    pp_algo.queryAddWithParser("gauss_charge_z_bins", tp5d_bins);
-
-                    // Set parameters for charge deposition
-                    bool const is_unity_particle_weight = false;
-                    bool const GetNumberDensity = true;
-
-                    // Measure beam size, extract the min, max of particle positions
-                    [[maybe_unused]] auto const [x_min, y_min, t_min, x_max, y_max, t_max] =
-                    pc.MinAndMaxPositions();
-
-                    int const num_bins = tp5d_bins;  // Set resolution
-                    amrex::Real const bin_min = t_min;
-                    amrex::Real const bin_max = t_max;
-                    amrex::Real const bin_size = (bin_max - bin_min) / (num_bins - 1);  // number of evaluation points
-                    // Allocate memory for the charge profile
-                    amrex::Gpu::DeviceVector<amrex::Real> charge_distribution(num_bins + 1, 0.0);
-                    // Call charge deposition function
-                    impactx::particles::wakefields::DepositCharge1D(pc, charge_distribution, bin_min, bin_size, is_unity_particle_weight);
-
-                    // Sum up all partial charge histograms to each MPI process to calculate
-                    // the global charge slope.
-                    amrex::ParallelAllReduce::Sum(
-                        charge_distribution.data(),
-                        charge_distribution.size(),
-                        amrex::ParallelDescriptor::Communicator()
-                    );
-
-                    // Call charge density derivative function
-                    amrex::Gpu::DeviceVector<amrex::Real> slopes(charge_distribution.size() - 1, 0.0);
-                    impactx::particles::wakefields::DerivativeCharge1D(charge_distribution, slopes, bin_size,GetNumberDensity);
-
-                    amrex::Real const * const beam_profile_slope = slopes.data();
-                    amrex::Real const * const beam_profile = charge_distribution.data();
-
                     // group together constants for the momentum push
                     amrex::ParticleReal const chargesign = charge / std::abs(charge);