Creating a new method instead of a flag

include/openmc/particle.h

@@ -50,10 +50,14 @@ class Particle : public ParticleData {
   //! \param wgt Weight of the secondary particle
   //! \param u Direction of the secondary particle
   //! \param E Energy of the secondary particle in [eV]
-  //! \param accumulate_E Whether to accumulate the energy of the secondary
-  //!        for adjustment to heating tallies
   //! \param type Particle type
-  void create_secondary(double wgt, Direction u, double E, ParticleType type, bool accumulate_E = true);
+  void create_secondary(double wgt, Direction u, double E, ParticleType type);
+
+  //! split a particle
+  //
+  //! creates a new particle with weight wgt
+  //! \param wgt Weight of the new particle
+  void split(double wgt);
 
   //! initialize from a source site
   //

src/particle.cpp

@@ -83,7 +83,7 @@ void Particle::move_distance(double length)
 }
 
 void Particle::create_secondary(
-  double wgt, Direction u, double E, ParticleType type, bool accumulate_E)
+  double wgt, Direction u, double E, ParticleType type)
 {
   // If energy is below cutoff for this particle, don't create secondary
   // particle
@@ -100,9 +100,18 @@ void Particle::create_secondary(
   bank.u = u;
   bank.E = settings::run_CE ? E : g();
   bank.time = time();
+  bank_second_E() += bank.E;
+}
 
-  if (accumulate_E)
-    bank_second_E() += bank.E;
+void Particle::split(double wgt) {
+  secondary_bank().emplace_back();
+  auto& bank {secondary_bank().back()};
+  bank.particle = type();
+  bank.wgt = wgt;
+  bank.r = r();
+  bank.u = u();
+  bank.E = settings::run_CE ? E() : g();
+  bank.time = time();
 }
 
 void Particle::from_source(const SourceSite* src)

src/weight_windows.cpp

@@ -114,7 +114,7 @@ void apply_weight_windows(Particle& p)
     // Create secondaries and divide weight among all particles
     int i_split = std::round(n_split);
     for (int l = 0; l < i_split - 1; l++) {
-      p.create_secondary(weight / n_split, p.u(), p.E(), p.type(), false);
+      p.split(weight / n_split);
     }
     // remaining weight is applied to current particle
     p.wgt() = weight / n_split;