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Add Reaction::xs methods

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This commit is contained in:
Paul Romano 2022-02-10 10:05:50 -06:00
parent 831c8d1c50
commit 8d002454f0
4 changed files with 56 additions and 57 deletions
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45
src/physics.cpp
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@ -541,23 +541,15 @@ Reaction& sample_fission(int i_nuclide, Particle& p)
}
}
// Get grid index and interpolatoin factor and sample fission cdf
int i_temp = p.neutron_xs(i_nuclide).index_temp;
int i_grid = p.neutron_xs(i_nuclide).index_grid;
double f = p.neutron_xs(i_nuclide).interp_factor;
// Get grid index and interpolation factor and sample fission cdf
const auto& micro = p.neutron_xs(i_nuclide);
double cutoff = prn(p.current_seed()) * p.neutron_xs(i_nuclide).fission;
double prob = 0.0;
// Loop through each partial fission reaction type
for (auto& rx : nuc->fission_rx_) {
// if energy is below threshold for this reaction, skip it
int threshold = rx->xs_[i_temp].threshold;
if (i_grid < threshold)
continue;
// add to cumulative probability
prob += (1.0 - f) * rx->xs_[i_temp].value[i_grid - threshold] +
f * rx->xs_[i_temp].value[i_grid - threshold + 1];
prob += rx->xs(micro);
// Create fission bank sites if fission occurs
if (prob > cutoff)
@ -573,25 +565,20 @@ void sample_photon_product(
int i_nuclide, Particle& p, int* i_rx, int* i_product)
{
// Get grid index and interpolation factor and sample photon production cdf
int i_temp = p.neutron_xs(i_nuclide).index_temp;
int i_grid = p.neutron_xs(i_nuclide).index_grid;
double f = p.neutron_xs(i_nuclide).interp_factor;
double cutoff = prn(p.current_seed()) * p.neutron_xs(i_nuclide).photon_prod;
const auto& micro = p.neutron_xs(i_nuclide);
double cutoff = prn(p.current_seed()) * micro.photon_prod;
double prob = 0.0;
// Loop through each reaction type
const auto& nuc {data::nuclides[i_nuclide]};
for (int i = 0; i < nuc->reactions_.size(); ++i) {
const auto& rx = nuc->reactions_[i];
int threshold = rx->xs_[i_temp].threshold;
// if energy is below threshold for this reaction, skip it
if (i_grid < threshold)
continue;
// Evaluate neutron cross section
double xs = ((1.0 - f) * rx->xs_[i_temp].value[i_grid - threshold] +
f * (rx->xs_[i_temp].value[i_grid - threshold + 1]));
const auto& rx = nuc->reactions_[i];
double xs = rx->xs(micro);
// if cross section is zero for this reaction, skip it
if (xs == 0.0)
continue;
for (int j = 0; j < rx->products_.size(); ++j) {
if (rx->products_[j].particle_ == ParticleType::photon) {
@ -663,8 +650,6 @@ void scatter(Particle& p, int i_nuclide)
const auto& nuc {data::nuclides[i_nuclide]};
const auto& micro {p.neutron_xs(i_nuclide)};
int i_temp = micro.index_temp;
int i_grid = micro.index_grid;
double f = micro.interp_factor;
// For tallying purposes, this routine might be called directly. In that
// case, we need to sample a reaction via the cutoff variable
@ -718,14 +703,8 @@ void scatter(Particle& p, int i_nuclide)
fatal_error("Did not sample any reaction for nuclide " + nuc->name_);
}
// if energy is below threshold for this reaction, skip it
const auto& xs {nuc->reactions_[i]->xs_[i_temp]};
if (i_grid < xs.threshold)
continue;
// add to cumulative probability
prob += (1.0 - f) * xs.value[i_grid - xs.threshold] +
f * xs.value[i_grid - xs.threshold + 1];
prob += nuc->reactions_[i]->xs(micro);
}
// Perform collision physics for inelastic scattering