EMFRAY

Activates Rayleigh (coherent) scattering and Compton binding and profile function corrections in selected regions. Only meaningful when the EMF option has been requested, explicitly or implicitly via option DEFAULTS.

See also EMF

     WHAT(1) = 1.0 : both Rayleigh scattering and Compton binding corrections
                     are activated, no Compton profile function
               2.0 : only Rayleigh scattering activated
               3.0 : only Compton binding corrections are activated
               4.0 : all Rayleigh, binding corrections, and profile function in
                     Compton activated
               5.0 : only Rayleigh scattering is activated
               6.0 : only binding corrections and profile function in Compton
                     are activated, no Rayleigh
               0.0 : ignored
             < 0.0 : no Rayleigh scattering and neither binding corrections nor
                     Compton profile function
               Default: if option DEFAULTS is used with SDUM = NEW-DEFAults, or
                     it is not used, the default is 3.0.
                     If it is used with SDUM = CALORIMEtry, EM-CASCAde, ICARUS,
                     HADROTHErapy or PRECISIOn, the default is 4.0.
                     With any other value of SDUM, the default is 0.0.

     WHAT(2) = lower bound (or corresponding name) of the region indices where
               Rayleigh scattering and/or Compton binding corrections and/or
               Compton profile function are requested.
               ("From region WHAT(2)...")
               Default = 2.0

     WHAT(3) = upper bound (or corresponding name) of the region indices where
               Rayleigh scattering and/or Compton binding corrections and/or
               Compton profile function are requested.
               ("...to region WHAT(3)...")
               Default = WHAT(2)

     WHAT(4) = step length in assigning indices.
               ("...in steps of WHAT(4)").
               Default = 1.0

     WHAT(5), WHAT(6), SDUM : not used

     Default (option EMFRAY not requested): if option DEFAULTS is used with
               SDUM = NEW-DEFAults or HADROTHErapy, binding corrections in
               Compton scattering are activated, but not Rayleigh scattering.
               If DEFAULTS is not used, or is used with SDUM = CALORIMEtry,
               EM-CASCAde, ICARUS or PRECISIOn, both are activated.
               With any other value of SDUM, binding corrections and Rayleigh
               scattering are not activated.

Notes:

1) The treatment of Rayleigh scattering is rather poor for non monoatomic materials (it assumes additivity and does not take into account important molecular effects). However, Rayleigh scattering, in general, has little effect on energy deposition and on particle transport.

2) The full treatment of electron binding and motion in Compton scattering (referred above as "binding corrections and profile function") is now available. It is particular important for low energies and/or heavy materials, and in general for all problems where the best accuracy for photon transport is requested.

Example (number based):

 *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
 EMF
 EMFRAY           1.0       8.0      12.0       4.0
 EMFRAY           3.0       9.0      15.0       2.0
 EMFRAY           1.0  EightReg  TwelvReg       4.0
 EMFRAY           3.0   NineReg  FifteenR       2.0
 *   In the above example, Compton binding corrections are requested in
 *   regions 8 to 15, excluding regions 10 and 14.
 *   Rayleigh scattering is requested only in regions 8 and 12

The same example, name-based:

 EMF
 EMFRAY           1.0  EightReg  TwelvReg       4.0
 EMFRAY           3.0   NineReg  FifteenR       2.0

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