crp/OpenMC
1
0
Fork 0
mirror of https://github.com/openmc-dev/openmc.git synced 2026-07-28 06:05:58 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 5

account for differences in band probabilities at different energies

Browse source
This commit is contained in:
Jon Walsh 2014-07-28 23:22:46 -06:00
parent ec21addbee
commit 6bfc2f73e0
1 changed files with 28 additions and 22 deletions
Download patch file Download diff file Expand all files Collapse all files

50
src/cross_section.F90
View file

@ -340,7 +340,8 @@ contains
real(8), intent(in) :: E ! energy
integer :: i_energy ! index for energy
integer :: i_table ! index for table
integer :: i_low ! band index at lower bounding energy
integer :: i_up ! band index at upper bounding energy
real(8) :: f ! interpolation factor
real(8) :: r ! pseudo-random number
real(8) :: elastic ! elastic cross section
@ -371,21 +372,26 @@ contains
! sample probability table using the cumulative distribution
r = prn()
i_table = 1
i_low = 1
do
if (urr % prob(i_energy, URR_CUM_PROB, i_table) > r) exit
i_table = i_table + 1
if (urr % prob(i_energy, URR_CUM_PROB, i_low) > r) exit
i_low = i_low + 1
end do
i_up = 1
do
if (urr % prob(i_energy + 1, URR_CUM_PROB, i_up) > r) exit
i_up = i_up + 1
end do
! determine elastic, fission, and capture cross sections from probability
! table
if (urr % interp == LINEAR_LINEAR) then
elastic = (ONE - f) * urr % prob(i_energy, URR_ELASTIC, i_table) + &
f * urr % prob(i_energy + 1, URR_ELASTIC, i_table)
fission = (ONE - f) * urr % prob(i_energy, URR_FISSION, i_table) + &
f * urr % prob(i_energy + 1, URR_FISSION, i_table)
capture = (ONE - f) * urr % prob(i_energy, URR_N_GAMMA, i_table) + &
f * urr % prob(i_energy + 1, URR_N_GAMMA, i_table)
elastic = (ONE - f) * urr % prob(i_energy, URR_ELASTIC, i_low) + &
f * urr % prob(i_energy + 1, URR_ELASTIC, i_up)
fission = (ONE - f) * urr % prob(i_energy, URR_FISSION, i_low) + &
f * urr % prob(i_energy + 1, URR_FISSION, i_up)
capture = (ONE - f) * urr % prob(i_energy, URR_N_GAMMA, i_low) + &
f * urr % prob(i_energy + 1, URR_N_GAMMA, i_up)
elseif (urr % interp == LOG_LOG) then
! Get logarithmic interpolation factor
f = log(E / urr % energy(i_energy)) / &
@ -393,29 +399,29 @@ contains
! Calculate elastic cross section/factor
elastic = ZERO
if (urr % prob(i_energy, URR_ELASTIC, i_table) > ZERO .and. &
urr % prob(i_energy + 1, URR_ELASTIC, i_table) > ZERO) then
if (urr % prob(i_energy, URR_ELASTIC, i_low) > ZERO .and. &
urr % prob(i_energy + 1, URR_ELASTIC, i_up) > ZERO) then
elastic = exp((ONE - f) * log(urr % prob(i_energy, URR_ELASTIC, &
i_table)) + f * log(urr % prob(i_energy + 1, URR_ELASTIC, &
i_table)))
i_low)) + f * log(urr % prob(i_energy + 1, URR_ELASTIC, &
i_up)))
end if
! Calculate fission cross section/factor
fission = ZERO
if (urr % prob(i_energy, URR_FISSION, i_table) > ZERO .and. &
urr % prob(i_energy + 1, URR_FISSION, i_table) > ZERO) then
if (urr % prob(i_energy, URR_FISSION, i_low) > ZERO .and. &
urr % prob(i_energy + 1, URR_FISSION, i_up) > ZERO) then
fission = exp((ONE - f) * log(urr % prob(i_energy, URR_FISSION, &
i_table)) + f * log(urr % prob(i_energy + 1, URR_FISSION, &
i_table)))
i_low)) + f * log(urr % prob(i_energy + 1, URR_FISSION, &
i_up)))
end if
! Calculate capture cross section/factor
capture = ZERO
if (urr % prob(i_energy, URR_N_GAMMA, i_table) > ZERO .and. &
urr % prob(i_energy + 1, URR_N_GAMMA, i_table) > ZERO) then
if (urr % prob(i_energy, URR_N_GAMMA, i_low) > ZERO .and. &
urr % prob(i_energy + 1, URR_N_GAMMA, i_up) > ZERO) then
capture = exp((ONE - f) * log(urr % prob(i_energy, URR_N_GAMMA, &
i_table)) + f * log(urr % prob(i_energy + 1, URR_N_GAMMA, &
i_table)))
i_low)) + f * log(urr % prob(i_energy + 1, URR_N_GAMMA, &
i_up)))
end if
end if