Implement the new fixed source bank model. For a fixed source calcultion the primary source bank is not allocated memory and source particles can not be read/written to files. The source particles for each history are now sampled at the start of initialize_history() through call to sample_external_source() with the appropriate seed. The timing stats for sampling has been removed from the output since this processing is now part of the transport timer

include/openmc/particle.h

@@ -181,6 +181,15 @@ public:
     int delayed_group; //!< particle delayed group
   };
 
+  //! Saved ("banked") state of primary source particle, for particle restart
+  struct RestartBank {
+	    Position r;
+	    Direction u;
+	    double E;
+	    double wgt;
+  };
+
+
   //==========================================================================
   // Constructors
 
@@ -361,6 +370,8 @@ public:
   #endif
 
   int64_t n_progeny_ {0}; // Number of progeny produced by this particle
+
+  RestartBank primary_source_; // primary source particle data
 };
 
 } // namespace openmc

src/output.cpp

@@ -441,8 +441,6 @@ void print_runtime()
     show_time("Time synchronizing fission bank", time_bank.elapsed(), 1);
     show_time("Sampling source sites", time_bank_sample.elapsed(), 2);
     show_time("SEND/RECV source sites", time_bank_sendrecv.elapsed(), 2);
-  } else {
-    show_time("Time sampling source", time_sample_source.elapsed(), 1);
   }
   show_time("Time accumulating tallies", time_tallies.elapsed(), 1);
   show_time("Total time for finalization", time_finalize.elapsed());

src/particle.cpp

@@ -128,6 +128,13 @@ Particle::from_source(const Bank* src)
     E_ = data::mg.energy_bin_avg_[g_];
   }
   E_last_ = E_;
+
+  // Saved copy of primary source attributes
+  primary_source_.r = src->r;
+  primary_source_.u = src->u;
+  primary_source_.E = E_last_;
+  primary_source_.wgt = wgt_;
+
 }
 
 void
@@ -681,11 +688,10 @@ Particle::write_restart() const
     write_dataset(file_id, "id", id_);
     write_dataset(file_id, "type", static_cast<int>(type_));
 
-    int64_t i = current_work_;
-    write_dataset(file_id, "weight", simulation::source_bank[i-1].wgt);
-    write_dataset(file_id, "energy", simulation::source_bank[i-1].E);
-    write_dataset(file_id, "xyz", simulation::source_bank[i-1].r);
-    write_dataset(file_id, "uvw", simulation::source_bank[i-1].u);
+    write_dataset(file_id, "weight", primary_source_.wgt);
+    write_dataset(file_id, "energy", primary_source_.E);
+    write_dataset(file_id, "xyz", primary_source_.r);
+    write_dataset(file_id, "uvw", primary_source_.u);
 
     // Close file
     file_close(file_id);

src/simulation.cpp

@@ -69,9 +69,10 @@ int openmc_simulation_init()
   // Determine how much work each process should do
   calculate_work();
 
-  // Allocate source bank, and for eigenvalue simulations also allocate the
-  // fission bank
-  allocate_banks();
+  // Allocate source and fission banks for eigenvalue simulations
+  if (settings::run_mode == RunMode::EIGENVALUE) {
+    allocate_banks();
+  }
 
   // If doing an event-based simulation, intialize the particle buffer
   // and event queues
@@ -105,7 +106,10 @@ int openmc_simulation_init()
     load_state_point();
     write_message("Resuming simulation...", 6);
   } else {
-    initialize_source();
+	//Only initialize primary source bank for eigenvalue simulations
+	if (settings::run_mode == RunMode::EIGENVALUE) {
+	  initialize_source();
+	}
   }
 
   // Display header
@@ -271,10 +275,8 @@ void allocate_banks()
 {
   // Allocate source bank
   simulation::source_bank.resize(simulation::work_per_rank);
-
-  if (settings::run_mode == RunMode::EIGENVALUE) {
-    init_fission_bank(3*simulation::work_per_rank);
-  }
+  // Allocate fission bank
+  init_fission_bank(3*simulation::work_per_rank);
 }
 
 void initialize_batch()
@@ -350,7 +352,7 @@ void finalize_batch()
       && !settings::cmfd_run) {
     if (contains(settings::sourcepoint_batch, simulation::current_batch)
         && settings::source_write && !settings::source_separate) {
-      bool b = true;
+      bool b = (settings::run_mode == RunMode::EIGENVALUE) ? true : false;
       openmc_statepoint_write(nullptr, &b);
     } else {
       bool b = false;
@@ -358,16 +360,18 @@ void finalize_batch()
     }
   }
 
-  // Write out a separate source point if it's been specified for this batch
-  if (contains(settings::sourcepoint_batch, simulation::current_batch)
-      && settings::source_write && settings::source_separate) {
-    write_source_point(nullptr);
-  }
+  if (settings::run_mode == RunMode::EIGENVALUE) {
+    // Write out a separate source point if it's been specified for this batch
+    if (contains(settings::sourcepoint_batch, simulation::current_batch)
+        && settings::source_write && settings::source_separate) {
+      write_source_point(nullptr);
+    }
 
-  // Write a continously-overwritten source point if requested.
-  if (settings::source_latest) {
-    auto filename = settings::path_output + "source.h5";
-    write_source_point(filename.c_str());
+    // Write a continously-overwritten source point if requested.
+    if (settings::source_latest) {
+      auto filename = settings::path_output + "source.h5";
+      write_source_point(filename.c_str());
+    }
   }
 }
 
@@ -429,18 +433,24 @@ void finalize_generation()
       }
     }
 
-  } else if (settings::run_mode == RunMode::FIXED_SOURCE) {
-    // For fixed-source mode, we need to sample the external source
-    simulation::time_sample_source.start();
-    fill_source_bank_fixedsource();
-    simulation::time_sample_source.stop();
   }
 }
 
 void initialize_history(Particle* p, int64_t index_source)
 {
   // set defaults
-  p->from_source(&simulation::source_bank[index_source - 1]);
+  if(settings::run_mode == RunMode::FIXED_SOURCE) {
+	// initialize random number seed
+	int64_t id = (simulation::total_gen + overall_generation() - 1)*settings::n_particles +
+	  simulation::work_index[mpi::rank] + index_source;
+	uint64_t seed = init_seed(id, STREAM_SOURCE);
+	// sample external source distribution then set
+	Particle::Bank site = sample_external_source(&seed);
+	p->from_source(&site);
+  } else if (settings::run_mode == RunMode::EIGENVALUE) {
+	// set defaults for eigenvalue simulations from primary bank
+    p->from_source(&simulation::source_bank[index_source - 1]);
+  }
   p->current_work_ = index_source;
 
   // set identifier for particle

src/source.cpp

@@ -396,21 +396,4 @@ void fill_source_bank_custom_source()
 #endif
 }
 
-void fill_source_bank_fixedsource()
-{
-  if (settings::path_source.empty() && settings::path_source_library.empty()) {
-    for (int64_t i = 0; i < simulation::work_per_rank; ++i) {
-      // initialize random number seed
-      int64_t id = (simulation::total_gen + overall_generation()) *
-        settings::n_particles + simulation::work_index[mpi::rank] + i + 1;
-      uint64_t seed = init_seed(id, STREAM_SOURCE);
-
-      // sample external source distribution
-      simulation::source_bank[i] = sample_external_source(&seed);
-    }
-  } else if (settings::path_source.empty() && !settings::path_source_library.empty()) {
-     fill_source_bank_custom_source();
-  }
-}
-
 } // namespace openmc

src/state_point.cpp

@@ -387,6 +387,7 @@ void load_state_point()
 
   // Logical flag for source present in statepoint file
   bool source_present;
+  read_attribute(file_id, "source_present", source_present);
 
   // Read information specific to eigenvalue run
   if (settings::run_mode == RunMode::EIGENVALUE) {
@@ -397,7 +398,6 @@ void load_state_point()
     settings::n_inactive = std::max(settings::n_inactive, temp);
 
     // Check to make sure source bank is present
-    read_attribute(file_id, "source_present", source_present);
     if (settings::path_sourcepoint == settings::path_statepoint &&
 	    !source_present) {
 	  fatal_error("Source bank must be contained in statepoint restart file");
@@ -409,7 +409,11 @@ void load_state_point()
 
   // Set k_sum, keff, and current_batch based on whether restart file is part
   // of active cycle or inactive cycle
-  restart_set_keff();
+  if (settings::run_mode == RunMode::EIGENVALUE) {
+    restart_set_keff();
+  }
+
+  // Set current batch number
   simulation::current_batch = simulation::restart_batch;
 
   // Read tallies to master. If we are using Parallel HDF5, all processes