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CORRFACT

allows to alter material density for dE/dx and nuclear processes on a region-by-region basis

See also ASSIGNMAt, COMPOUND, LOW--MAT, MATERIAL, MAT-PROP

     WHAT(1) >= 0.0 : density scaling factor for charged particle ionisation
                      processes (dE/dx, delta ray production, M\oller and Bhabha
                      scattering)
              = 0.0 : ignored
              < 0.0 : reset to default
              Default: 1.0

     WHAT(2) >= 0.0 : density scaling factor for all other processes
              = 0.0 : ignored
              < 0.0 : reset to default
              Default: 1.0

     WHAT(3): not used

     WHAT(4): lower index bound (or corresponding name) of regions where the
              scaling factors shall apply
               "From region WHAT(4)..."
              Default: 2.0

     WHAT(5): upper index bound (or corresponding name) of regions where the
              scaling factors shall apply
               "...to region WHAT(5)..."
              Default: WHAT(4)

     WHAT(6): step length in assigning region numbers
               "...in steps of WHAT(6)"
              Default: 1.0

     SDUM   : not used

     Default (option CORRFACT not requested): no density scaling factors are
             applied

Note:

• 1) Option CORRFACT is mainly used in connection with voxel geometries derived from a CT scan, where particle transport is done often in an equivalent material (e.g., water), but accounting for the density variations provided by scan at the voxel level. While this approach is reliable for what concerns ionisation, other reactions, which do not scale with density, must be simulated for the actual material composition.

Example, in a number-based input:

 *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
 * Multiply density by  a 0.85 factor for what concerns atomic processes
 * in regions 7, 8, 9, 10, 11, 12
 CORRFACT        0.85       0.0       0.0       7.0       12.

The same example, in a name-based input, supposing that the geometry is made of 12 regions:

 CORRFACT        0.85       0.0       0.0  The7thRg  @LASTREG
 * Note the use of the name @LASTREG to indicate the maximum number of regions
 * in the problem