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Merge pull request #328 from paulromano/urr-zeros

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Check for negative values when calculating cross sections from probability tables
This commit is contained in:
walshjon 2014-10-02 19:38:36 -04:00
commit 68bfb1a49a
1 changed files with 11 additions and 6 deletions
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17
src/cross_section.F90
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@ -113,7 +113,7 @@ contains
atom_density * micro_xs(i_nuclide) % elastic
! Add contributions to material macroscopic absorption cross section
material_xs % absorption = material_xs % absorption + &
material_xs % absorption = material_xs % absorption + &
atom_density * micro_xs(i_nuclide) % absorption
! Add contributions to material macroscopic fission cross section
@ -123,7 +123,7 @@ contains
! Add contributions to material macroscopic nu-fission cross section
material_xs % nu_fission = material_xs % nu_fission + &
atom_density * micro_xs(i_nuclide) % nu_fission
! Add contributions to material macroscopic energy release from fission
material_xs % kappa_fission = material_xs % kappa_fission + &
atom_density * micro_xs(i_nuclide) % kappa_fission
@ -214,7 +214,7 @@ contains
! Calculate microscopic nuclide nu-fission cross section
micro_xs(i_nuclide) % nu_fission = (ONE - f) * nuc % nu_fission( &
i_grid) + f * nuc % nu_fission(i_grid+1)
! Calculate microscopic nuclide kappa-fission cross section
! The ENDF standard (ENDF-102) states that MT 18 stores
! the fission energy as the Q_value (fission(1))
@ -276,7 +276,7 @@ contains
f = ZERO
else
i_grid = binary_search(sab % inelastic_e_in, sab % n_inelastic_e_in, E)
f = (E - sab%inelastic_e_in(i_grid)) / &
f = (E - sab%inelastic_e_in(i_grid)) / &
(sab%inelastic_e_in(i_grid+1) - sab%inelastic_e_in(i_grid))
end if
@ -475,6 +475,11 @@ contains
fission = fission * micro_xs(i_nuclide) % fission
end if
! Check for negative values
if (elastic < ZERO) elastic = ZERO
if (fission < ZERO) fission = ZERO
if (capture < ZERO) capture = ZERO
! Set elastic, absorption, fission, and total cross sections. Note that the
! total cross section is calculated as sum of partials rather than using the
! table-provided value
@ -538,11 +543,11 @@ contains
if (nuc % energy_0K(i_grid) == nuc % energy_0K(i_grid+1)) then
i_grid = i_grid + 1
end if
! calculate interpolation factor
f = (E - nuc % energy_0K(i_grid)) &
& / (nuc % energy_0K(i_grid + 1) - nuc % energy_0K(i_grid))
! Calculate microscopic nuclide elastic cross section
xs_out = (ONE - f) * nuc % elastic_0K(i_grid) &
& + f * nuc % elastic_0K(i_grid + 1)