Added cell_born attribute on Particle type.

src/particle_header.f90

@@ -26,6 +26,7 @@ module particle_header
 
      ! Indices for various arrays
      integer    :: cell          ! index for current cell
+     integer    :: cell_born     ! index for cell particle was born in
      integer    :: universe      ! index for current universe
      integer    :: lattice       ! index for current lattice
      integer    :: surface       ! index for current surface

src/physics.f90

@@ -49,6 +49,9 @@ contains
                "Could not locate cell for particle at: ", p % xyz
           call fatal_error(msg)
        end if
+
+       ! set birth cell attribute
+       p % cell_born = p % cell
     end if
 
     if (verbosity >= 9) then

src/source.f90

@@ -172,6 +172,7 @@ contains
     p % wgt           = ONE
     p % alive         = .true.
     p % cell          = 0
+    p % cell_born     = 0
     p % universe      = 0
     p % lattice       = 0
     p % surface       = 0

src/tally.f90

@@ -297,7 +297,7 @@ contains
 
        ! determine next bornin bin
        if (t % n_bornin_bins > 0) then
-          ! bornin_bin = get_next_bin(MAP_BORNIN, p % bornin, i)
+          bornin_bin = get_next_bin(MAP_BORNIN, p % cell_born, i)
           if (bornin_bin == NO_BIN_FOUND) cycle
        else
           bornin_bin = 1