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openmc-dev / openmc / 21686031975

04 Feb 2026 07:50PM UTC coverage: 81.024% (-0.7%) from 81.763%
21686031975

Pull #3755

github

web-flow
Merge 27d6053a4 into b41e22f68
Pull Request #3755: Warn users that tally heating score with photon bin but without electron and positron bins.

16378 of 22828 branches covered (71.75%)

Branch coverage included in aggregate %.

22 of 23 new or added lines in 1 file covered. (95.65%)

862 existing lines in 51 files now uncovered.

54491 of 64639 relevant lines covered (84.3%)

8259986.93 hits per line

Source File
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83.69
/src/particle.cpp
1
#include "openmc/particle.h"
2

3
#include <algorithm> // copy, min
4
#include <cmath>     // log, abs
5

6
#include <fmt/core.h>
7

8
#include "openmc/bank.h"
9
#include "openmc/capi.h"
10
#include "openmc/cell.h"
11
#include "openmc/collision_track.h"
12
#include "openmc/constants.h"
13
#include "openmc/dagmc.h"
14
#include "openmc/error.h"
15
#include "openmc/geometry.h"
16
#include "openmc/hdf5_interface.h"
17
#include "openmc/material.h"
18
#include "openmc/message_passing.h"
19
#include "openmc/mgxs_interface.h"
20
#include "openmc/nuclide.h"
21
#include "openmc/particle_data.h"
22
#include "openmc/photon.h"
23
#include "openmc/physics.h"
24
#include "openmc/physics_mg.h"
25
#include "openmc/random_lcg.h"
26
#include "openmc/settings.h"
27
#include "openmc/simulation.h"
28
#include "openmc/source.h"
29
#include "openmc/surface.h"
30
#include "openmc/tallies/derivative.h"
31
#include "openmc/tallies/tally.h"
32
#include "openmc/tallies/tally_scoring.h"
33
#include "openmc/track_output.h"
34
#include "openmc/weight_windows.h"
35

36
#ifdef OPENMC_DAGMC_ENABLED
37
#include "DagMC.hpp"
38
#endif
39

40
namespace openmc {
41

42
//==============================================================================
43
// Particle implementation
44
//==============================================================================
45

46
double Particle::speed() const
377,599,272✔
47
{
48
  if (settings::run_CE) {
377,599,272✔
49
    // Determine mass in eV/c^2
50
    double mass;
51
    switch (this->type().pdg_number()) {
189,968,598!
52
    case PDG_NEUTRON:
183,124,409✔
53
      mass = MASS_NEUTRON_EV;
183,124,409✔
54
      break;
183,124,409✔
55
    case PDG_PHOTON:
1,982,913✔
56
      mass = 0.0;
1,982,913✔
57
      break;
1,982,913✔
58
    case PDG_ELECTRON:
4,861,276✔
59
    case PDG_POSITRON:
60
      mass = MASS_ELECTRON_EV;
4,861,276✔
61
      break;
4,861,276✔
62
    default:
×
63
      fatal_error("Unsupported particle for speed calculation.");
×
64
    }
65
    // Equivalent to C * sqrt(1-(m/(m+E))^2) without problem at E<<m:
66
    return C_LIGHT * std::sqrt(this->E() * (this->E() + 2 * mass)) /
189,968,598✔
67
           (this->E() + mass);
189,968,598✔
68
  } else {
69
    auto& macro_xs = data::mg.macro_xs_[this->material()];
187,630,674✔
70
    int macro_t = this->mg_xs_cache().t;
187,630,674✔
71
    int macro_a = macro_xs.get_angle_index(this->u());
187,630,674✔
72
    return 1.0 / macro_xs.get_xs(MgxsType::INVERSE_VELOCITY, this->g(), nullptr,
187,630,674✔
73
                   nullptr, nullptr, macro_t, macro_a);
187,630,674✔
74
  }
75
}
76

77
bool Particle::create_secondary(
10,139,237✔
78
  double wgt, Direction u, double E, ParticleType type)
79
{
80
  // If energy is below cutoff for this particle, don't create secondary
81
  // particle
82
  int idx = type.transport_index();
10,139,237✔
83
  if (idx == C_NONE) {
10,139,237!
84
    return false;
×
85
  }
86
  if (E < settings::energy_cutoff[idx]) {
10,139,237✔
87
    return false;
4,847,376✔
88
  }
89

90
  auto& bank = secondary_bank().emplace_back();
5,291,861✔
91
  bank.particle = type;
5,291,861✔
92
  bank.wgt = wgt;
5,291,861✔
93
  bank.r = r();
5,291,861✔
94
  bank.u = u;
5,291,861✔
95
  bank.E = settings::run_CE ? E : g();
5,291,861!
96
  bank.time = time();
5,291,861✔
97
  bank_second_E() += bank.E;
5,291,861✔
98
  return true;
5,291,861✔
99
}
100

101
void Particle::split(double wgt)
371,452✔
102
{
103
  auto& bank = secondary_bank().emplace_back();
371,452✔
104
  bank.particle = type();
371,452✔
105
  bank.wgt = wgt;
371,452✔
106
  bank.r = r();
371,452✔
107
  bank.u = u();
371,452✔
108
  bank.E = settings::run_CE ? E() : g();
371,452✔
109
  bank.time = time();
371,452✔
110

111
  // Convert signed index to a signed surface ID
112
  if (surface() == SURFACE_NONE) {
371,452!
113
    bank.surf_id = SURFACE_NONE;
371,452✔
114
  } else {
UNCOV
115
    int surf_id = model::surfaces[surface_index()]->id_;
×
UNCOV
116
    bank.surf_id = (surface() > 0) ? surf_id : -surf_id;
×
117
  }
118
}
371,452✔
119

120
void Particle::from_source(const SourceSite* src)
21,603,625✔
121
{
122
  // Reset some attributes
123
  clear();
21,603,625✔
124
  surface() = SURFACE_NONE;
21,603,625✔
125
  cell_born() = C_NONE;
21,603,625✔
126
  material() = C_NONE;
21,603,625✔
127
  n_collision() = 0;
21,603,625✔
128
  fission() = false;
21,603,625✔
129
  zero_flux_derivs();
21,603,625✔
130
  lifetime() = 0.0;
21,603,625✔
131
#ifdef OPENMC_DAGMC_ENABLED
132
  history().reset();
133
#endif
134

135
  // Copy attributes from source bank site
136
  type() = src->particle;
21,603,625✔
137
  wgt() = src->wgt;
21,603,625✔
138
  wgt_last() = src->wgt;
21,603,625✔
139
  r() = src->r;
21,603,625✔
140
  u() = src->u;
21,603,625✔
141
  r_born() = src->r;
21,603,625✔
142
  r_last_current() = src->r;
21,603,625✔
143
  r_last() = src->r;
21,603,625✔
144
  u_last() = src->u;
21,603,625✔
145
  if (settings::run_CE) {
21,603,625✔
146
    E() = src->E;
11,081,998✔
147
    g() = 0;
11,081,998✔
148
  } else {
149
    g() = static_cast<int>(src->E);
10,521,627✔
150
    g_last() = static_cast<int>(src->E);
10,521,627✔
151
    E() = data::mg.energy_bin_avg_[g()];
10,521,627✔
152
  }
153
  E_last() = E();
21,603,625✔
154
  time() = src->time;
21,603,625✔
155
  time_last() = src->time;
21,603,625✔
156
  parent_nuclide() = src->parent_nuclide;
21,603,625✔
157
  delayed_group() = src->delayed_group;
21,603,625✔
158

159
  // Convert signed surface ID to signed index
160
  if (src->surf_id != SURFACE_NONE) {
21,603,625✔
161
    int index_plus_one = model::surface_map[std::abs(src->surf_id)] + 1;
10,000✔
162
    surface() = (src->surf_id > 0) ? index_plus_one : -index_plus_one;
10,000!
163
  }
164
}
21,603,625✔
165

166
void Particle::event_calculate_xs()
375,104,121✔
167
{
168
  // Set the random number stream
169
  stream() = STREAM_TRACKING;
375,104,121✔
170

171
  // Store pre-collision particle properties
172
  wgt_last() = wgt();
375,104,121✔
173
  E_last() = E();
375,104,121✔
174
  u_last() = u();
375,104,121✔
175
  r_last() = r();
375,104,121✔
176
  time_last() = time();
375,104,121✔
177

178
  // Reset event variables
179
  event() = TallyEvent::KILL;
375,104,121✔
180
  event_nuclide() = NUCLIDE_NONE;
375,104,121✔
181
  event_mt() = REACTION_NONE;
375,104,121✔
182

183
  // If the cell hasn't been determined based on the particle's location,
184
  // initiate a search for the current cell. This generally happens at the
185
  // beginning of the history and again for any secondary particles
186
  if (lowest_coord().cell() == C_NONE) {
375,104,121✔
187
    if (!exhaustive_find_cell(*this)) {
20,832,426!
188
      mark_as_lost(
×
189
        "Could not find the cell containing particle " + std::to_string(id()));
×
190
      return;
×
191
    }
192

193
    // Set birth cell attribute
194
    if (cell_born() == C_NONE)
20,832,426!
195
      cell_born() = lowest_coord().cell();
20,832,426✔
196

197
    // Initialize last cells from current cell
198
    for (int j = 0; j < n_coord(); ++j) {
43,210,782✔
199
      cell_last(j) = coord(j).cell();
22,378,356✔
200
    }
201
    n_coord_last() = n_coord();
20,832,426✔
202
  }
203

204
  // Write particle track.
205
  if (write_track())
375,104,121✔
206
    write_particle_track(*this);
1,282✔
207

208
  if (settings::check_overlaps)
375,104,121!
209
    check_cell_overlap(*this);
×
210

211
  // Calculate microscopic and macroscopic cross sections
212
  if (material() != MATERIAL_VOID) {
375,104,121✔
213
    if (settings::run_CE) {
364,941,329✔
214
      if (material() != material_last() || sqrtkT() != sqrtkT_last() ||
209,226,751✔
215
          density_mult() != density_mult_last()) {
31,916,096✔
216
        // If the material is the same as the last material and the
217
        // temperature hasn't changed, we don't need to lookup cross
218
        // sections again.
219
        model::materials[material()]->calculate_xs(*this);
145,395,431✔
220
      }
221
    } else {
222
      // Get the MG data; unlike the CE case above, we have to re-calculate
223
      // cross sections for every collision since the cross sections may
224
      // be angle-dependent
225
      data::mg.macro_xs_[material()].calculate_xs(*this);
187,630,674✔
226

227
      // Update the particle's group while we know we are multi-group
228
      g_last() = g();
187,630,674✔
229
    }
230
  } else {
231
    macro_xs().total = 0.0;
10,162,792✔
232
    macro_xs().absorption = 0.0;
10,162,792✔
233
    macro_xs().fission = 0.0;
10,162,792✔
234
    macro_xs().nu_fission = 0.0;
10,162,792✔
235
  }
236
}
237

238
void Particle::event_advance()
375,104,121✔
239
{
240
  // Find the distance to the nearest boundary
241
  boundary() = distance_to_boundary(*this);
375,104,121✔
242

243
  // Sample a distance to collision
244
  if (type() == ParticleType::electron() ||
745,354,899✔
245
      type() == ParticleType::positron()) {
370,250,778✔
246
    collision_distance() = material() == MATERIAL_VOID ? INFINITY : 0.0;
4,861,276!
247
  } else if (macro_xs().total == 0.0) {
370,242,845✔
248
    collision_distance() = INFINITY;
10,162,792✔
249
  } else {
250
    collision_distance() = -std::log(prn(current_seed())) / macro_xs().total;
360,080,053✔
251
  }
252

253
  double speed = this->speed();
375,104,121✔
254
  double time_cutoff = settings::time_cutoff[type().transport_index()];
375,104,121✔
255
  double distance_cutoff =
256
    (time_cutoff < INFTY) ? (time_cutoff - time()) * speed : INFTY;
375,104,121✔
257

258
  // Select smaller of the three distances
259
  double distance =
260
    std::min({boundary().distance(), collision_distance(), distance_cutoff});
375,104,121✔
261

262
  // Advance particle in space and time
263
  this->move_distance(distance);
375,104,121✔
264
  double dt = distance / speed;
375,104,121✔
265
  this->time() += dt;
375,104,121✔
266
  this->lifetime() += dt;
375,104,121✔
267

268
  // Score timed track-length tallies
269
  if (!model::active_timed_tracklength_tallies.empty()) {
375,104,121✔
270
    score_timed_tracklength_tally(*this, distance);
329,847✔
271
  }
272

273
  // Score track-length tallies
274
  if (!model::active_tracklength_tallies.empty()) {
375,104,121✔
275
    score_tracklength_tally(*this, distance);
140,285,077✔
276
  }
277

278
  // Score track-length estimate of k-eff
279
  if (settings::run_mode == RunMode::EIGENVALUE && type().is_neutron()) {
375,104,121✔
280
    keff_tally_tracklength() += wgt() * distance * macro_xs().nu_fission;
310,221,562✔
281
  }
282

283
  // Score flux derivative accumulators for differential tallies.
284
  if (!model::active_tallies.empty()) {
375,104,121✔
285
    score_track_derivative(*this, distance);
155,245,880✔
286
  }
287

288
  // Set particle weight to zero if it hit the time boundary
289
  if (distance == distance_cutoff) {
375,104,121✔
290
    wgt() = 0.0;
20,448✔
291
  }
292
}
375,104,121✔
293

294
void Particle::event_cross_surface()
201,850,148✔
295
{
296
  // Saving previous cell data
297
  for (int j = 0; j < n_coord(); ++j) {
587,178,593✔
298
    cell_last(j) = coord(j).cell();
385,328,445✔
299
  }
300
  n_coord_last() = n_coord();
201,850,148✔
301

302
  // Set surface that particle is on and adjust coordinate levels
303
  surface() = boundary().surface();
201,850,148✔
304
  n_coord() = boundary().coord_level();
201,850,148✔
305

306
  if (boundary().lattice_translation()[0] != 0 ||
201,850,148✔
307
      boundary().lattice_translation()[1] != 0 ||
355,408,866✔
308
      boundary().lattice_translation()[2] != 0) {
153,558,718✔
309
    // Particle crosses lattice boundary
310

311
    bool verbose = settings::verbosity >= 10 || trace();
65,431,389!
312
    cross_lattice(*this, boundary(), verbose);
65,431,389✔
313
    event() = TallyEvent::LATTICE;
65,431,389✔
314
  } else {
315
    // Particle crosses surface
316
    const auto& surf {model::surfaces[surface_index()].get()};
136,418,759✔
317
    // If BC, add particle to surface source before crossing surface
318
    if (surf->surf_source_ && surf->bc_) {
136,418,759✔
319
      add_surf_source_to_bank(*this, *surf);
62,506,104✔
320
    }
321
    this->cross_surface(*surf);
136,418,759✔
322
    // If no BC, add particle to surface source after crossing surface
323
    if (surf->surf_source_ && !surf->bc_) {
136,418,758✔
324
      add_surf_source_to_bank(*this, *surf);
73,795,844✔
325
    }
326
    if (settings::weight_window_checkpoint_surface) {
136,418,758!
UNCOV
327
      apply_weight_windows(*this);
×
328
    }
329
    event() = TallyEvent::SURFACE;
136,418,758✔
330
  }
331
  // Score cell to cell partial currents
332
  if (!model::active_surface_tallies.empty()) {
201,850,147✔
333
    score_surface_tally(*this, model::active_surface_tallies);
3,174,797✔
334
  }
335
}
201,850,147✔
336

337
void Particle::event_collide()
247,412,721✔
338
{
339
  // Score collision estimate of keff
340
  if (settings::run_mode == RunMode::EIGENVALUE && type().is_neutron()) {
247,412,721✔
341
    keff_tally_collision() += wgt() * macro_xs().nu_fission / macro_xs().total;
193,136,276✔
342
  }
343

344
  // Score surface current tallies -- this has to be done before the collision
345
  // since the direction of the particle will change and we need to use the
346
  // pre-collision direction to figure out what mesh surfaces were crossed
347

348
  if (!model::active_meshsurf_tallies.empty())
247,412,721✔
349
    score_surface_tally(*this, model::active_meshsurf_tallies);
5,736,266✔
350

351
  // Clear surface component
352
  surface() = SURFACE_NONE;
247,412,721✔
353

354
  if (settings::run_CE) {
247,412,721✔
355
    collision(*this);
85,316,314✔
356
  } else {
357
    collision_mg(*this);
162,096,407✔
358
  }
359

360
  // Collision track feature to recording particle interaction
361
  if (settings::collision_track) {
247,412,721✔
362
    collision_track_record(*this);
13,799✔
363
  }
364

365
  // Score collision estimator tallies -- this is done after a collision
366
  // has occurred rather than before because we need information on the
367
  // outgoing energy for any tallies with an outgoing energy filter
368
  if (!model::active_collision_tallies.empty())
247,412,721✔
369
    score_collision_tally(*this);
9,425,419✔
370
  if (!model::active_analog_tallies.empty()) {
247,412,721✔
371
    if (settings::run_CE) {
26,507,882✔
372
      score_analog_tally_ce(*this);
26,398,040✔
373
    } else {
374
      score_analog_tally_mg(*this);
109,842✔
375
    }
376
  }
377

378
  if (!model::active_pulse_height_tallies.empty() && type().is_photon()) {
247,412,721✔
379
    pht_collision_energy();
184✔
380
  }
381

382
  // Reset banked weight during collision
383
  n_bank() = 0;
247,412,721✔
384
  bank_second_E() = 0.0;
247,412,721✔
385
  wgt_bank() = 0.0;
247,412,721✔
386
  zero_delayed_bank();
247,412,721✔
387

388
  // Reset fission logical
389
  fission() = false;
247,412,721✔
390

391
  // Save coordinates for tallying purposes
392
  r_last_current() = r();
247,412,721✔
393

394
  // Set last material to none since cross sections will need to be
395
  // re-evaluated
396
  material_last() = C_NONE;
247,412,721✔
397

398
  // Set all directions to base level -- right now, after a collision, only
399
  // the base level directions are changed
400
  for (int j = 0; j < n_coord() - 1; ++j) {
260,361,578✔
401
    if (coord(j + 1).rotated()) {
12,948,857✔
402
      // If next level is rotated, apply rotation matrix
403
      const auto& m {model::cells[coord(j).cell()]->rotation_};
947,874✔
404
      const auto& u {coord(j).u()};
947,874✔
405
      coord(j + 1).u() = u.rotate(m);
947,874✔
406
    } else {
407
      // Otherwise, copy this level's direction
408
      coord(j + 1).u() = coord(j).u();
12,000,983✔
409
    }
410
  }
411

412
  // Score flux derivative accumulators for differential tallies.
413
  if (!model::active_tallies.empty())
247,412,721✔
414
    score_collision_derivative(*this);
73,724,603✔
415

416
#ifdef OPENMC_DAGMC_ENABLED
417
  history().reset();
418
#endif
419
}
247,412,721✔
420

421
void Particle::event_revive_from_secondary()
375,104,120✔
422
{
423
  // If particle has too many events, display warning and kill it
424
  ++n_event();
375,104,120✔
425
  if (n_event() == settings::max_particle_events) {
375,104,120!
426
    warning("Particle " + std::to_string(id()) +
×
427
            " underwent maximum number of events.");
428
    wgt() = 0.0;
×
429
  }
430

431
  // Check for secondary particles if this particle is dead
432
  if (!alive()) {
375,104,120✔
433
    // Write final position for this particle
434
    if (write_track()) {
20,832,480✔
435
      write_particle_track(*this);
850✔
436
    }
437

438
    // If no secondary particles, break out of event loop
439
    if (secondary_bank().empty())
20,832,480✔
440
      return;
15,169,135✔
441

442
    from_source(&secondary_bank().back());
5,663,345✔
443
    secondary_bank().pop_back();
5,663,345✔
444
    n_event() = 0;
5,663,345✔
445
    bank_second_E() = 0.0;
5,663,345✔
446

447
    // Subtract secondary particle energy from interim pulse-height results
448
    if (!model::active_pulse_height_tallies.empty() &&
5,664,754✔
449
        this->type().is_photon()) {
1,409✔
450
      // Since the birth cell of the particle has not been set we
451
      // have to determine it before the energy of the secondary particle can be
452
      // removed from the pulse-height of this cell.
453
      if (lowest_coord().cell() == C_NONE) {
55!
454
        bool verbose = settings::verbosity >= 10 || trace();
55!
455
        if (!exhaustive_find_cell(*this, verbose)) {
55!
456
          mark_as_lost("Could not find the cell containing particle " +
×
457
                       std::to_string(id()));
×
458
          return;
×
459
        }
460
        // Set birth cell attribute
461
        if (cell_born() == C_NONE)
55!
462
          cell_born() = lowest_coord().cell();
55✔
463

464
        // Initialize last cells from current cell
465
        for (int j = 0; j < n_coord(); ++j) {
110✔
466
          cell_last(j) = coord(j).cell();
55✔
467
        }
468
        n_coord_last() = n_coord();
55✔
469
      }
470
      pht_secondary_particles();
55✔
471
    }
472

473
    // Enter new particle in particle track file
474
    if (write_track())
5,663,345✔
475
      add_particle_track(*this);
720✔
476
  }
477
}
478

479
void Particle::event_death()
15,169,135✔
480
{
481
#ifdef OPENMC_DAGMC_ENABLED
482
  history().reset();
483
#endif
484

485
  // Finish particle track output.
486
  if (write_track()) {
15,169,135✔
487
    finalize_particle_track(*this);
130✔
488
  }
489

490
// Contribute tally reduction variables to global accumulator
491
#pragma omp atomic
492
  global_tally_absorption += keff_tally_absorption();
15,169,135✔
493
#pragma omp atomic
494
  global_tally_collision += keff_tally_collision();
15,169,135✔
495
#pragma omp atomic
496
  global_tally_tracklength += keff_tally_tracklength();
15,169,135✔
497
#pragma omp atomic
498
  global_tally_leakage += keff_tally_leakage();
15,169,135✔
499

500
  // Reset particle tallies once accumulated
501
  keff_tally_absorption() = 0.0;
15,169,135✔
502
  keff_tally_collision() = 0.0;
15,169,135✔
503
  keff_tally_tracklength() = 0.0;
15,169,135✔
504
  keff_tally_leakage() = 0.0;
15,169,135✔
505

506
  if (!model::active_pulse_height_tallies.empty()) {
15,169,135✔
507
    score_pulse_height_tally(*this, model::active_pulse_height_tallies);
500✔
508
  }
509

510
  // Record the number of progeny created by this particle.
511
  // This data will be used to efficiently sort the fission bank.
512
  if (settings::run_mode == RunMode::EIGENVALUE) {
15,169,135✔
513
    int64_t offset = id() - 1 - simulation::work_index[mpi::rank];
12,809,200✔
514
    simulation::progeny_per_particle[offset] = n_progeny();
12,809,200✔
515
  }
516
}
15,169,135✔
517

518
void Particle::pht_collision_energy()
184✔
519
{
520
  // Adds the energy particles lose in a collision to the pulse-height
521

522
  // determine index of cell in pulse_height_cells
523
  auto it = std::find(model::pulse_height_cells.begin(),
184✔
524
    model::pulse_height_cells.end(), lowest_coord().cell());
184✔
525

526
  if (it != model::pulse_height_cells.end()) {
184!
527
    int index = std::distance(model::pulse_height_cells.begin(), it);
184✔
528
    pht_storage()[index] += E_last() - E();
184✔
529

530
    // If the energy of the particle is below the cutoff, it will not be sampled
531
    // so its energy is added to the pulse-height in the cell
532
    int photon = ParticleType::photon().transport_index();
184✔
533
    if (E() < settings::energy_cutoff[photon]) {
184✔
534
      pht_storage()[index] += E();
75✔
535
    }
536
  }
537
}
184✔
538

539
void Particle::pht_secondary_particles()
55✔
540
{
541
  // Removes the energy of secondary produced particles from the pulse-height
542

543
  // determine index of cell in pulse_height_cells
544
  auto it = std::find(model::pulse_height_cells.begin(),
55✔
545
    model::pulse_height_cells.end(), cell_born());
55✔
546

547
  if (it != model::pulse_height_cells.end()) {
55!
548
    int index = std::distance(model::pulse_height_cells.begin(), it);
55✔
549
    pht_storage()[index] -= E();
55✔
550
  }
551
}
55✔
552

553
void Particle::cross_surface(const Surface& surf)
136,598,533✔
554
{
555

556
  if (settings::verbosity >= 10 || trace()) {
136,598,533✔
557
    write_message(1, "    Crossing surface {}", surf.id_);
3✔
558
  }
559

560
// if we're crossing a CSG surface, make sure the DAG history is reset
561
#ifdef OPENMC_DAGMC_ENABLED
562
  if (surf.geom_type() == GeometryType::CSG)
563
    history().reset();
564
#endif
565

566
  // Handle any applicable boundary conditions.
567
  if (surf.bc_ && settings::run_mode != RunMode::PLOTTING &&
199,148,341!
568
      settings::run_mode != RunMode::VOLUME) {
62,549,808✔
569
    surf.bc_->handle_particle(*this, surf);
62,538,904✔
570
    return;
62,538,904✔
571
  }
572

573
  // ==========================================================================
574
  // SEARCH NEIGHBOR LISTS FOR NEXT CELL
575

576
#ifdef OPENMC_DAGMC_ENABLED
577
  // in DAGMC, we know what the next cell should be
578
  if (surf.geom_type() == GeometryType::DAG) {
579
    int32_t i_cell = next_cell(surface_index(), cell_last(n_coord() - 1),
580
                       lowest_coord().universe()) -
581
                     1;
582
    // save material, temperature, and density multiplier
583
    material_last() = material();
584
    sqrtkT_last() = sqrtkT();
585
    density_mult_last() = density_mult();
586
    // set new cell value
587
    lowest_coord().cell() = i_cell;
588
    auto& cell = model::cells[i_cell];
589

590
    cell_instance() = 0;
591
    if (cell->distribcell_index_ >= 0)
592
      cell_instance() = cell_instance_at_level(*this, n_coord() - 1);
593

594
    material() = cell->material(cell_instance());
595
    sqrtkT() = cell->sqrtkT(cell_instance());
596
    density_mult() = cell->density_mult(cell_instance());
597
    return;
598
  }
599
#endif
600

601
  bool verbose = settings::verbosity >= 10 || trace();
74,059,629!
602
  if (neighbor_list_find_cell(*this, verbose)) {
74,059,629✔
603
    return;
74,056,908✔
604
  }
605

606
  // ==========================================================================
607
  // COULDN'T FIND PARTICLE IN NEIGHBORING CELLS, SEARCH ALL CELLS
608

609
  // Remove lower coordinate levels
610
  n_coord() = 1;
2,721✔
611
  bool found = exhaustive_find_cell(*this, verbose);
2,721✔
612

613
  if (settings::run_mode != RunMode::PLOTTING && (!found)) {
2,721!
614
    // If a cell is still not found, there are two possible causes: 1) there is
615
    // a void in the model, and 2) the particle hit a surface at a tangent. If
616
    // the particle is really traveling tangent to a surface, if we move it
617
    // forward a tiny bit it should fix the problem.
618

619
    surface() = SURFACE_NONE;
529✔
620
    n_coord() = 1;
529✔
621
    r() += TINY_BIT * u();
529✔
622

623
    // Couldn't find next cell anywhere! This probably means there is an actual
624
    // undefined region in the geometry.
625

626
    if (!exhaustive_find_cell(*this, verbose)) {
529!
627
      mark_as_lost("After particle " + std::to_string(id()) +
1,586✔
628
                   " crossed surface " + std::to_string(surf.id_) +
2,114✔
629
                   " it could not be located in any cell and it did not leak.");
630
      return;
528✔
631
    }
632
  }
633
}
634

635
void Particle::cross_vacuum_bc(const Surface& surf)
3,155,026✔
636
{
637
  // Score any surface current tallies -- note that the particle is moved
638
  // forward slightly so that if the mesh boundary is on the surface, it is
639
  // still processed
640

641
  if (!model::active_meshsurf_tallies.empty()) {
3,155,026✔
642
    // TODO: Find a better solution to score surface currents than
643
    // physically moving the particle forward slightly
644

645
    r() += TINY_BIT * u();
85,202✔
646
    score_surface_tally(*this, model::active_meshsurf_tallies);
85,202✔
647
  }
648

649
  // Score to global leakage tally
650
  keff_tally_leakage() += wgt();
3,155,026✔
651

652
  // Kill the particle
653
  wgt() = 0.0;
3,155,026✔
654

655
  // Display message
656
  if (settings::verbosity >= 10 || trace()) {
3,155,026!
657
    write_message(1, "    Leaked out of surface {}", surf.id_);
1✔
658
  }
659
}
3,155,026✔
660

661
void Particle::cross_reflective_bc(const Surface& surf, Direction new_u)
59,270,392✔
662
{
663
  // Do not handle reflective boundary conditions on lower universes
664
  if (n_coord() != 1) {
59,270,392!
665
    mark_as_lost("Cannot reflect particle " + std::to_string(id()) +
×
666
                 " off surface in a lower universe.");
667
    return;
×
668
  }
669

670
  // Score surface currents since reflection causes the direction of the
671
  // particle to change. For surface filters, we need to score the tallies
672
  // twice, once before the particle's surface attribute has changed and
673
  // once after. For mesh surface filters, we need to artificially move
674
  // the particle slightly back in case the surface crossing is coincident
675
  // with a mesh boundary
676

677
  if (!model::active_surface_tallies.empty()) {
59,270,392✔
678
    score_surface_tally(*this, model::active_surface_tallies);
25,911✔
679
  }
680

681
  if (!model::active_meshsurf_tallies.empty()) {
59,270,392✔
682
    Position r {this->r()};
4,262,317✔
683
    this->r() -= TINY_BIT * u();
4,262,317✔
684
    score_surface_tally(*this, model::active_meshsurf_tallies);
4,262,317✔
685
    this->r() = r;
4,262,317✔
686
  }
687

688
  // Set the new particle direction
689
  u() = new_u;
59,270,392✔
690

691
  // Reassign particle's cell and surface
692
  coord(0).cell() = cell_last(0);
59,270,392✔
693
  surface() = -surface();
59,270,392✔
694

695
  // If a reflective surface is coincident with a lattice or universe
696
  // boundary, it is necessary to redetermine the particle's coordinates in
697
  // the lower universes.
698
  // (unless we're using a dagmc model, which has exactly one universe)
699
  n_coord() = 1;
59,270,392✔
700
  if (surf.geom_type() != GeometryType::DAG &&
118,540,784!
701
      !neighbor_list_find_cell(*this)) {
59,270,392!
702
    mark_as_lost("Couldn't find particle after reflecting from surface " +
×
703
                 std::to_string(surf.id_) + ".");
×
704
    return;
×
705
  }
706

707
  // Set previous coordinate going slightly past surface crossing
708
  r_last_current() = r() + TINY_BIT * u();
59,270,392✔
709

710
  // Diagnostic message
711
  if (settings::verbosity >= 10 || trace()) {
59,270,392!
712
    write_message(1, "    Reflected from surface {}", surf.id_);
×
713
  }
714
}
715

716
void Particle::cross_periodic_bc(
204,892✔
717
  const Surface& surf, Position new_r, Direction new_u, int new_surface)
718
{
719
  // Do not handle periodic boundary conditions on lower universes
720
  if (n_coord() != 1) {
204,892!
721
    mark_as_lost(
×
722
      "Cannot transfer particle " + std::to_string(id()) +
×
723
      " across surface in a lower universe. Boundary conditions must be "
724
      "applied to root universe.");
725
    return;
×
726
  }
727

728
  // Score surface currents since reflection causes the direction of the
729
  // particle to change -- artificially move the particle slightly back in
730
  // case the surface crossing is coincident with a mesh boundary
731
  if (!model::active_meshsurf_tallies.empty()) {
204,892!
732
    Position r {this->r()};
×
733
    this->r() -= TINY_BIT * u();
×
734
    score_surface_tally(*this, model::active_meshsurf_tallies);
×
735
    this->r() = r;
×
736
  }
737

738
  // Adjust the particle's location and direction.
739
  r() = new_r;
204,892✔
740
  u() = new_u;
204,892✔
741

742
  // Reassign particle's surface
743
  surface() = new_surface;
204,892✔
744

745
  // Figure out what cell particle is in now
746
  n_coord() = 1;
204,892✔
747

748
  if (!neighbor_list_find_cell(*this)) {
204,892!
749
    mark_as_lost("Couldn't find particle after hitting periodic "
×
750
                 "boundary on surface " +
×
751
                 std::to_string(surf.id_) + ".");
×
752
    return;
×
753
  }
754

755
  // Set previous coordinate going slightly past surface crossing
756
  r_last_current() = r() + TINY_BIT * u();
204,892✔
757

758
  // Diagnostic message
759
  if (settings::verbosity >= 10 || trace()) {
204,892!
760
    write_message(1, "    Hit periodic boundary on surface {}", surf.id_);
×
761
  }
762
}
763

764
void Particle::mark_as_lost(const char* message)
529✔
765
{
766
  // Print warning and write lost particle file
767
  warning(message);
529✔
768
  if (settings::max_write_lost_particles < 0 ||
529✔
769
      simulation::n_lost_particles < settings::max_write_lost_particles) {
500✔
770
    write_restart();
39✔
771
  }
772
  // Increment number of lost particles
773
  wgt() = 0.0;
529✔
774
#pragma omp atomic
775
  simulation::n_lost_particles += 1;
529✔
776

777
  // Count the total number of simulated particles (on this processor)
778
  auto n = simulation::current_batch * settings::gen_per_batch *
529✔
779
           simulation::work_per_rank;
780

781
  // Abort the simulation if the maximum number of lost particles has been
782
  // reached
783
  if (simulation::n_lost_particles >= settings::max_lost_particles &&
529✔
784
      simulation::n_lost_particles >= settings::rel_max_lost_particles * n) {
1!
785
    fatal_error("Maximum number of lost particles has been reached.");
1✔
786
  }
787
}
528✔
788

789
void Particle::write_restart() const
39✔
790
{
791
  // Dont write another restart file if in particle restart mode
792
  if (settings::run_mode == RunMode::PARTICLE)
39✔
793
    return;
2✔
794

795
  // Set up file name
796
  auto filename = fmt::format("{}particle_{}_{}.h5", settings::path_output,
797
    simulation::current_batch, id());
74✔
798

799
#pragma omp critical(WriteParticleRestart)
800
  {
801
    // Create file
802
    hid_t file_id = file_open(filename, 'w');
37✔
803

804
    // Write filetype and version info
805
    write_attribute(file_id, "filetype", "particle restart");
37✔
806
    write_attribute(file_id, "version", VERSION_PARTICLE_RESTART);
37✔
807
    write_attribute(file_id, "openmc_version", VERSION);
37✔
808
#ifdef GIT_SHA1
809
    write_attr_string(file_id, "git_sha1", GIT_SHA1);
810
#endif
811

812
    // Write data to file
813
    write_dataset(file_id, "current_batch", simulation::current_batch);
37✔
814
    write_dataset(file_id, "generations_per_batch", settings::gen_per_batch);
37✔
815
    write_dataset(file_id, "current_generation", simulation::current_gen);
37✔
816
    write_dataset(file_id, "n_particles", settings::n_particles);
37✔
817
    switch (settings::run_mode) {
37!
818
    case RunMode::FIXED_SOURCE:
25✔
819
      write_dataset(file_id, "run_mode", "fixed source");
25✔
820
      break;
25✔
821
    case RunMode::EIGENVALUE:
12✔
822
      write_dataset(file_id, "run_mode", "eigenvalue");
12✔
823
      break;
12✔
824
    case RunMode::PARTICLE:
×
825
      write_dataset(file_id, "run_mode", "particle restart");
×
826
      break;
×
827
    default:
×
828
      break;
×
829
    }
830
    write_dataset(file_id, "id", id());
37✔
831
    write_dataset(file_id, "type", type().pdg_number());
37✔
832

833
    int64_t i = current_work();
37✔
834
    if (settings::run_mode == RunMode::EIGENVALUE) {
37✔
835
      // take source data from primary bank for eigenvalue simulation
836
      write_dataset(file_id, "weight", simulation::source_bank[i - 1].wgt);
12✔
837
      write_dataset(file_id, "energy", simulation::source_bank[i - 1].E);
12✔
838
      write_dataset(file_id, "xyz", simulation::source_bank[i - 1].r);
12✔
839
      write_dataset(file_id, "uvw", simulation::source_bank[i - 1].u);
12✔
840
      write_dataset(file_id, "time", simulation::source_bank[i - 1].time);
12✔
841
    } else if (settings::run_mode == RunMode::FIXED_SOURCE) {
25!
842
      // re-sample using rng random number seed used to generate source particle
843
      int64_t id = (simulation::total_gen + overall_generation() - 1) *
25✔
844
                     settings::n_particles +
25✔
845
                   simulation::work_index[mpi::rank] + i;
25✔
846
      uint64_t seed = init_seed(id, STREAM_SOURCE);
25✔
847
      // re-sample source site
848
      auto site = sample_external_source(&seed);
25✔
849
      write_dataset(file_id, "weight", site.wgt);
25✔
850
      write_dataset(file_id, "energy", site.E);
25✔
851
      write_dataset(file_id, "xyz", site.r);
25✔
852
      write_dataset(file_id, "uvw", site.u);
25✔
853
      write_dataset(file_id, "time", site.time);
25✔
854
    }
855

856
    // Close file
857
    file_close(file_id);
37✔
858
  } // #pragma omp critical
859
}
37✔
860

861
void Particle::update_neutron_xs(
657,088,749✔
862
  int i_nuclide, int i_grid, int i_sab, double sab_frac, double ncrystal_xs)
863
{
864
  // Get microscopic cross section cache
865
  auto& micro = this->neutron_xs(i_nuclide);
657,088,749✔
866

867
  // If the cache doesn't match, recalculate micro xs
868
  if (this->E() != micro.last_E || this->sqrtkT() != micro.last_sqrtkT ||
896,812,931✔
869
      i_sab != micro.index_sab || sab_frac != micro.sab_frac ||
1,126,866,276✔
870
      ncrystal_xs != micro.ncrystal_xs) {
230,053,345!
871
    data::nuclides[i_nuclide]->calculate_xs(i_sab, i_grid, sab_frac, *this);
427,035,404✔
872

873
    // If NCrystal is being used, update micro cross section cache
874
    micro.ncrystal_xs = ncrystal_xs;
427,035,404✔
875
    if (ncrystal_xs >= 0.0) {
427,035,404✔
876
      data::nuclides[i_nuclide]->calculate_elastic_xs(*this);
1,001,723✔
877
      ncrystal_update_micro(ncrystal_xs, micro);
1,001,723✔
878
    }
879
  }
880
}
657,088,749✔
881

882
//==============================================================================
883
// Non-method functions
884
//==============================================================================
885
void add_surf_source_to_bank(Particle& p, const Surface& surf)
136,301,948✔
886
{
887
  if (simulation::current_batch <= settings::n_inactive ||
242,870,527✔
888
      simulation::surf_source_bank.full()) {
106,568,579✔
889
    return;
136,290,053✔
890
  }
891

892
  // If a cell/cellfrom/cellto parameter is defined
893
  if (settings::ssw_cell_id != C_NONE) {
31,878✔
894

895
    // Retrieve cell index and storage type
896
    int cell_idx = model::cell_map[settings::ssw_cell_id];
24,236✔
897

898
    if (surf.bc_) {
24,236✔
899
      // Leave if cellto with vacuum boundary condition
900
      if (surf.bc_->type() == "vacuum" &&
17,786!
901
          settings::ssw_cell_type == SSWCellType::To) {
3,075✔
902
        return;
1,126✔
903
      }
904

905
      // Leave if other boundary condition than vacuum
906
      if (surf.bc_->type() != "vacuum") {
13,585✔
907
        return;
11,636✔
908
      }
909
    }
910

911
    // Check if the cell of interest has been exited
912
    bool exited = false;
11,474✔
913
    for (int i = 0; i < p.n_coord_last(); ++i) {
30,894✔
914
      if (p.cell_last(i) == cell_idx) {
19,420✔
915
        exited = true;
6,888✔
916
      }
917
    }
918

919
    // Check if the cell of interest has been entered
920
    bool entered = false;
11,474✔
921
    for (int i = 0; i < p.n_coord(); ++i) {
27,468✔
922
      if (p.coord(i).cell() == cell_idx) {
15,994✔
923
        entered = true;
5,452✔
924
      }
925
    }
926

927
    // Vacuum boundary conditions: return if cell is not exited
928
    if (surf.bc_) {
11,474✔
929
      if (surf.bc_->type() == "vacuum" && !exited) {
1,949!
930
        return;
1,349✔
931
      }
932
    } else {
933

934
      // If we both enter and exit the cell of interest
935
      if (entered && exited) {
9,525✔
936
        return;
2,656✔
937
      }
938

939
      // If we did not enter nor exit the cell of interest
940
      if (!entered && !exited) {
6,869✔
941
        return;
1,041✔
942
      }
943

944
      // If cellfrom and the cell before crossing is not the cell of
945
      // interest
946
      if (settings::ssw_cell_type == SSWCellType::From && !exited) {
5,828✔
947
        return;
1,097✔
948
      }
949

950
      // If cellto and the cell after crossing is not the cell of interest
951
      if (settings::ssw_cell_type == SSWCellType::To && !entered) {
4,731✔
952
        return;
1,078✔
953
      }
954
    }
955
  }
956

957
  SourceSite site;
11,895✔
958
  site.r = p.r();
11,895✔
959
  site.u = p.u();
11,895✔
960
  site.E = p.E();
11,895✔
961
  site.time = p.time();
11,895✔
962
  site.wgt = p.wgt();
11,895✔
963
  site.delayed_group = p.delayed_group();
11,895✔
964
  site.surf_id = surf.id_;
11,895✔
965
  site.particle = p.type();
11,895✔
966
  site.parent_id = p.id();
11,895✔
967
  site.progeny_id = p.n_progeny();
11,895✔
968
  int64_t idx = simulation::surf_source_bank.thread_safe_append(site);
11,895✔
969
}
970

971
} // namespace openmc
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