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13-Sep-2023

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( 10.04.2024 )
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MAT-PROP

Provides extra information about materials

See also MATERIAL, STERNHEIme

This command can be used for several different tasks:

1) to supply extra information about gaseous materials and materials with fictitious or effective density.
2) to override the default average ionisation potential.
3) to set a flag to call the user routine USRMED every time a particle is going to be transported in the selected material(s)
4) to set the energy threshold for DPAs (Displacements Per Atom)

For SDUM whatever except DPA-ENER, USERDIREctive:

     WHAT(1) = Gas pressure in atmospheres.
              0.0   : ignored
              < 0.0 : resets to 1 atm a possible previously input
                      pressure value

     WHAT(2) = RHOR factor : this factor multiplies the density of the
              material(s) when calculating the density effect parameters
              (e.g. if a reduced density is used to simulate voids, but
              of course the density effect parameters must be computed
              with the actual local physical density at the microscopic
              level). See Note 3) below.
             = 0.0 : ignored
             < 0.0 : a possible previously input value is restored to
                     default = 1.0
              Default = 1.0

     WHAT(3) > 0: average ionisation potential to be used for dE/dx
                  calculations (eV)
             < 0: a default value of the average ionisation potential
                  is obtained from the systematics of Ziegler [Zie77]
                  or Sternheimer, Berger and Seltzer [Ste84]
             = 0: ignored
              Default: ionisation potential calculated from systematics

     WHAT(4) = lower bound of the indices of materials, or corresponding
               name, in which gas pressure, RHOR factor or ionisation
               potential are set
               ("From material WHAT(4)...")
               Default = 3.0

     WHAT(5) = upper bound of the indices of materials, or corresponding
               name, in which gas pressure, RHOR factor or ionisation
               potential are set
               ("... to material WHAT(5)...")
               Default = WHAT(4)

     WHAT(6) = step length in assigning indices
               ("...in steps of WHAT(6)")
               Default = 1.

     Default (option MAT-PROP not given): if the density of the default
            material or that assigned by a MATERIAL card is > 0.01, the
            material is not assumed to be a gas. Otherwise it is a gas
            at a default pressure of 1 atmosphere. If the material is a
            compound, the average ionisation potential is that resulting
            from applying Bragg's rule of additivity to stopping power.

For SDUM = DPA-ENER:

     WHAT(1) > 0.0: Damage energy threshold (eV) for the given materials
                    (see Note 5)
             = 0.0: ignored
               Default = 30 eV

     WHAT(2) = Not used

     WHAT(3) = Not used

     WHAT(4) = lower bound of the indices of materials, or corresponding
               name, in which the damage energy threshold has to be applied
               ("From material WHAT(4)...")
               Default = 3.0

     WHAT(5) = upper bound of the indices of materials, or corresponding
               name, in which the damage energy threshold has to be applied
               ("... to material WHAT(5)...")
               Default = WHAT(4)

     WHAT(6) = step length in assigning indices
               ("...in steps of WHAT(6)")
               Default = 1.

     Default (option MAT-PROP not given): Damage energy threshold = 30 eV
               for all materials

For SDUM = USERDIREctive

     WHAT(1) = 0.0 : ignored
             > 0.0 : a call to the user routine USRMED will be performed
                     at run time every time a particle is going to be transported
                     in the selected materials (spot depositions ARE anyway performed)
             < 0.0 : a possible previously given value is restored to
                     default = no call
               Default = no call (-1.0)

     WHAT(2) = Not used

     WHAT(3) = Not used

     WHAT(4) = lower bound of the indices of materials for which the
               call to USRMED has to be performed
               ("From material WHAT(4)...")
               Default = 3.0

     WHAT(5) = upper bound of the indices of materials for which the
               call to USRMED has to be performed
               ("... to material WHAT(5)...")
               Default = WHAT(4)

     WHAT(6) = step length in assigning indices
               ("...in steps of WHAT(6)")
               Default = 1.

     Default (option MAT-PROP not given): no extra information about the
           assigned materials is supplied.

Notes:

         SDUM = blank (i.e. /= DPA-ENER, USERDIREctive):

1) When issuing a MATERIAL definition the gas pressure is set to 1 if the density RHO is < 0.01. If this value is not acceptable to the user, a MAT-PROP card must be issued AFTER the MATERIAL card to force a different value of the gas pressure. Note that this is one of the rare cases (with GLOBAL, DEFAULTS and PLOTGEOM) where sequential order of input cards is of importance in FLUKA. A non-zero value of WHAT(1) must be given only for gases: it is important when calculating the density effect parameters of the stopping power (see Note 1 to option STERNHEIme and Note 2 here below).

2) If WHAT(1) is set to a value > 0.0, the transport of charged particles will be calculated according to a density RHO defined at the actual pressure by the corresponding MATERIAL card, while the density effect correction to stopping power will be calculated using a density RHO(NTP) = RHO/WHAT(1) and then re-scaled to the actual density RHO.

3) When giving a WHAT(2) non-zero value, remember that if RHO (defined by a MATERIAL card) indicates the "transport (effective) density", the "physical density" used to calculate the density effect on stopping power will be RHOR*RHO = WHAT(2)*RHO

         SDUM = DPA-ENER:

4) Displacement damage can be induced by all particles produced in a cascade, including high energy photons. The latter, however, have to initiate a reaction producing charged particles, neutrons or ions.

5) The damage threshold is the minimum energy needed to produce a defect. Typical values used in the NJOY99 code [NJOY] are: Li: 10 eV, C in SiC: 20 eV, Graphite: 30...35 eV, Al: 27 eV, Si: 25 eV, Mn, Fe, Co, Ni, Cu, Nb: 40 eV, Mo: 60 eV, W: 90 eV, Pb: 25 eV

6) In most problems, the expected DPA values are generally expressed by very small numbers.

         SDUM = USERDIREctive:

7) User routine USRMED is typically used to implement albedo and refraction, especially in connection with optical photon transport as defined by OPT-PROP. See (13) for instructions.

Example 1 (number based):

 * Call USRMED every time a particle is going to be transported in Pb Glass or
 * in plexiglas (PMMA)
 *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
 MATERIAL          1.   1.00794 8.3748E-5        3.       0.0       1. HYDROGEN
 MATERIAL          6.    12.011     2.265        6.       0.0       0. CARBON
 MATERIAL          8.   15.9994  0.001429        8.       0.0       0. OXYGEN
 MATERIAL         14.   28.0855      2.33       14.       0.0       0. SILICON
 MATERIAL         22.     47.88      4.54       11.       0.0       0. TITANIUM
 MATERIAL         33.   74.9216      5.73       12.       0.0       0. ARSENIC
 MATERIAL         82.     207.2     11.35       17.       0.0       0. LEAD
 MATERIAL          0.        0.      6.22       18.       0.0       0. LEADGLAS
 COMPOUND   -0.156453        8. -0.080866       14. -0.008092      11. LEADGLAS
 COMPOUND   -0.002651       12. -0.751938       17.       0.0       0. LEADGLAS
 MATERIAL          0.        0.      1.19       15.       0.0       0. PMMA
 COMPOUND   -0.080538        3. -0.599848        6. -0.319614       8. PMMA
 MAT-PROP         1.0       0.0       0.0       15.       18.       3. USERDIRE

The same example, name based:

 *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
 MATERIAL          1.   1.00794 8.3748E-5        3.       0.0       1. HYDROGEN
 MATERIAL          6.    12.011     2.265        6.       0.0       0. CARBON
 MATERIAL          8.   15.9994  0.001429        8.       0.0       0. OXYGEN
 MATERIAL         14.   28.0855      2.33       14.       0.0       0. SILICON
 MATERIAL         22.     47.88      4.54       11.       0.0       0. TITANIUM
 MATERIAL         33.   74.9216      5.73       12.       0.0       0. ARSENIC
 MATERIAL         82.     207.2     11.35       17.       0.0       0. LEAD
 MATERIAL          0.        0.      6.22       18.       0.0       0. LEADGLAS
 COMPOUND   -0.156453    OXYGEN -0.080866   SILICON -0.008092 TITANIUM LEADGLAS
 COMPOUND   -0.002651   ARSENIC -0.751938      LEAD       0.0       0. LEADGLAS
 MATERIAL          0.        0.      1.19       15.       0.0       0. PMMA
 COMPOUND   -0.080538  HYDROGEN -0.599848    CARBON -0.319614   OXYGEN PMMA
 MAT-PROP         1.0       0.0       0.0      PMMA  LEADGLAS       3. USERDIRE

Example 2:

 * Lung tissue with ICRP composition and Sternheimer parameters
 *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
 MATERIAL          1.   1.00794 8.3748E-5        3.       0.0       1. HYDROGEN
 MATERIAL          6.    12.011     2.265        6.       0.0       0. CARBON
 MATERIAL          7.  14.00674 0.0011653        7.       0.0       0. NITROGEN
 MATERIAL          8.   15.9994  0.001429        8.       0.0       0. OXYGEN
 MATERIAL         12.    24.305      1.74        9.       0.0       0. MAGNESIU
 MATERIAL         11.  22.98977     0.971       10.       0.0       0. SODIUM
 MATERIAL         26.    55.847     7.874       11.       0.0       0. IRON
 MATERIAL         16.    32.066       2.0       12.       0.0       0. SULFUR
 MATERIAL         17.   35.4527 2.9947E-3       13        0.0       0. CHLORINE
 MATERIAL         19.   39.0983     0.862       14.       0.0       0. POTASSIU
 MATERIAL         15.  30.97376       2.2       16.       0.0       0. PHOSPHO
 MATERIAL         30.     65.39     7.133       17.       0.0       0. ZINC
 MATERIAL         20.    40.078      1.55       21.       0.0       0. CALCIUM
 * Local density of lung is 1.05 g/cm3
 MATERIAL         0.0       0.0      1.05       18.       0.0       0. LUNG
 COMPOUND   -0.101278        3.  -0.10231        6.  -0.02865       7. LUNG
 COMPOUND   -0.757072        8.  -0.00184       10.  -0.00073       9. LUNG
 COMPOUND     -0.0008       16.  -0.00225       12.  -0.00266      13. LUNG
 COMPOUND    -0.00194       14.  -0.00009       21.  -0.00037      11. LUNG
 COMPOUND    -0.00001       17.        0.        0.        0.       0. LUNG
 * Average density of lung is 1.05*0.286 = 0.3 g/cm3. Average ionisation
 * potential is 75.3 eV (At. Data Nucl. Data Tab. 30, 261 (1984))
 MAT-PROP         0.0     0.286      75.3       18.        0.       0.
 STERNHEI      3.4708    0.2261    2.8001   0.08588    3.5353       0.  18

The same example, name based:

 *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
 MATERIAL          1.   1.00794 8.3748E-5        3.       0.0       1. HYDROGEN
 MATERIAL          6.    12.011     2.265        6.       0.0       0. CARBON
 MATERIAL          7.  14.00674 0.0011653        7.       0.0       0. NITROGEN
 MATERIAL          8.   15.9994  0.001429        8.       0.0       0. OXYGEN
 MATERIAL         12.    24.305      1.74        9.       0.0       0. MAGNESIU
 MATERIAL         11.  22.98977     0.971       10.       0.0       0. SODIUM
 MATERIAL         26.    55.847     7.874       11.       0.0       0. IRON
 MATERIAL         16.    32.066       2.0       12.       0.0       0. SULFUR
 MATERIAL         17.   35.4527 2.9947E-3       13        0.0       0. CHLORINE
 MATERIAL         19.   39.0983     0.862       14.       0.0       0. POTASSIU
 MATERIAL         15.  30.97376       2.2       16.       0.0       0. PHOSPHO
 MATERIAL         30.     65.39     7.133       17.       0.0       0. ZINC
 MATERIAL         20.    40.078      1.55       21.       0.0       0. CALCIUM
 MATERIAL         0.0       0.0      1.05       18.       0.0       0. LUNG
 COMPOUND   -0.101278  HYDROGEN  -0.10231    CARBON  -0.02865 NITROGEN LUNG
 COMPOUND   -0.757072    OXYGEN  -0.00184    SODIUM  -0.00073 MAGNESIU LUNG
 COMPOUND     -0.0008   PHOSPHO  -0.00225    SULFUR  -0.00266 CHLORINE LUNG
 COMPOUND    -0.00194  POTASSIU  -0.00009   CALCIUM  -0.00037     IRON LUNG
 COMPOUND    -0.00001      ZINC        0.        0.        0.       0. LUNG
 MAT-PROP         0.0     0.286      75.3      LUNG        0.       0.
 STERNHEI      3.4708    0.2261    2.8001   0.08588    3.5353       0. LUNG

Example 3 (number based):

 * Definition of air at non-standard pressure.
 *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
 MATERIAL          6.    12.011     2.265        6.       0.0       0. CARBON
 MATERIAL          7.  14.00674 0.0011653        7.       0.0       0. NITROGEN
 MATERIAL          8.   15.9994  0.001429        8.       0.0       0. OXYGEN
 MATERIAL         18.    39.948  1.662E-3       20.       0.0       0. ARGON
 * AIR defined as air with normal NTP density (0.001205)
 MATERIAL         0.0       0.0  0.001205       10.       0.0       0. AIR
 COMPOUND   -0.000124        6. -0.755267        7. -0.231781       8. AIR
 COMPOUND   -0.012827       20.                                        AIR
 * AIR2 defined as air with a density 0.002410, double of that at NTP
 MATERIAL         0.0       0.0  0.002410       11.       0.0       0. AIR2
 COMPOUND   -0.000124        6. -0.755267        7. -0.231781       8. AIR2
 COMPOUND   -0.012827       20.                                        AIR2
 * The pressure of AIR2 is 2 atm. Set also the ionisation potential = 85.7 eV
 MAT-PROP         2.0       0.0      85.7       10.
 STERNHEI     10.5961    1.7418    4.2759   0.10914    3.3994       0.  11

The same example, name based:

 *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
 MATERIAL          6.    12.011     2.265        6.       0.0       0. CARBON
 MATERIAL          7.  14.00674 0.0011653        7.       0.0       0. NITROGEN
 MATERIAL          8.   15.9994  0.001429        8.       0.0       0. OXYGEN
 MATERIAL         18.    39.948  1.662E-3       20.       0.0       0. ARGON
 MATERIAL         0.0       0.0  0.001205       10.       0.0       0. AIR
 COMPOUND   -0.000124    CARBON -0.755267  NITROGEN -0.231781   OXYGEN AIR
 COMPOUND   -0.012827     ARGON                                        AIR
 MATERIAL         0.0       0.0  0.002410       11.       0.0       0. AIR2
 COMPOUND   -0.000124    CARBON -0.755267  NITROGEN -0.231781   OXYGEN AIR2
 COMPOUND   -0.012827     ARGON                                        AIR2
 MAT-PROP         2.0       0.0      85.7       AIR
 STERNHEI     10.5961    1.7418    4.2759   0.10914    3.3994       0. AIR2

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