FLUKA: MAT-PROP
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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)
* Start_Devel_seq
For SDUM
whatever except DPA-ENER, LOWNTEMP, USERDIREctive:
* End_Devel_seq
* Start_Prod_seq
For SDUM
whatever except DPA-ENER, USERDIREctive:
* End_Prod_seq
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
< 0.0: resets to default
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
* Start_Devel_seq
For SDUM
= LOWNTEMP:
WHAT(1)
= Temperature ratio (T_actual/T_xsec) with respect to the
nominal one. The nominal temperature T_xsec (given by
WHAT(3)
, see below) is the temperature for which the
neutron cross sections of the FLUKA material(s) concerned
have been prepared (see the Table in 10}). See Notes d.1),
d.2), d.3) for more details and limitations.
= 0.0 : ignored
< 0.0 : a possible previously given value is restored to
default = 1.0
Default
= 1.0
WHAT(2)
= Number of (thermal) groups to which the temperature
ratio has to be applied. It must be <= N_th, where
N_th is the number of thermal groups in the cross section
library. If WHAT(2)
< N_th, the last WHAT(2)
groups are
affected (see the LOW-NEUT option for setting the number
of thermal groups).
= 0.0 : ignored
< 0.0 : a possible previously given value is restored to
default = 0.0
Default
= 0.0 (i.e., no correction, the whole command is
ignored).
WHAT(3)
= Nominal temperature (K) of the indicated FLUKA materials
= 0.0 : ignored
< 0.0 : a possible previously given value is restored to
default (3rd identifier, see below)
Default
= the temperature given as 3rd identifier of the
associated low energy neutron data set (see
LOW-MAT and the cross section description in 10})
WHAT(4)
= lower bound of the indices of materials, or corresponding
name, in which the temperature rescaling 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 temperature rescaling 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): No cross section re-scaling
* End_Devel_seq
For SDUM
= USERDIREctive
WHAT(1)
= 0.0 : ignored
> 0.0 : a call to the user routine USRMED (see 13.2.28}) will be
performed at run time every time a particle is going to be
transported in the selected materials (spot depositions ARE
anyway performed: i.e., they cannot be killed by USRMED)
< 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:
* Start_Devel_seq
SDUM
= blank (i.e. /= DPA-ENER, LOWNTEMP, USERDIREctive):
* End_Devel_seq
* Start_Prod_seq
SDUM
= blank (i.e. /= DPA-ENER, USERDIREctive):
* End_Prod_seq
1) When issuing a MATERIAL definition the gas pressure is set to
1 atm 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):
MATERIAL 1. 0.0 8.3748E-5 3. 0.0 1. HYDROGEN
MATERIAL 6. 0.0 2.265 6. 0.0 0. CARBON
MATERIAL 8. 0.0 0.001429 8. 0.0 0. OXYGEN
MATERIAL 14. 0.0 2.33 14. 0.0 0. SILICON
MATERIAL 22. 0.0 4.54 11. 0.0 0. TITANIUM
MATERIAL 33. 0.0 5.73 12. 0.0 0. ARSENIC
MATERIAL 82. 0.0 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:
MATERIAL 1. 0.0 8.3748E-5 0.0 0.0 1. HYDROGEN
MATERIAL 6. 0.0 2.265 0.0 0.0 0. CARBON
MATERIAL 8. 0.0 0.001429 0.0 0.0 0. OXYGEN
MATERIAL 14. 0.0 2.33 0.0 0.0 0. SILICON
MATERIAL 22. 0.0 4.54 0.0 0.0 0. TITANIUM
MATERIAL 33. 0.0 5.73 0.0 0.0 0. ARSENIC
MATERIAL 82. 0.0 11.35 0.0 0.0 0. LEAD
MATERIAL 0. 0. 6.22 0.0 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 0.0 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 (number based):
MATERIAL 1. 0.0 8.3748E-5 3. 0.0 1. HYDROGEN
MATERIAL 6. 0.0 2.265 6. 0.0 0. CARBON
MATERIAL 7. 0.0 0.0011653 7. 0.0 0. NITROGEN
MATERIAL 8. 0.0 0.001429 8. 0.0 0. OXYGEN
MATERIAL 12. 0.0 1.74 9. 0.0 0. MAGNESIU
MATERIAL 11. 0.0 0.971 10. 0.0 0. SODIUM
MATERIAL 26. 0.0 7.874 11. 0.0 0. IRON
MATERIAL 16. 0.0 2.0 12. 0.0 0. SULFUR
MATERIAL 17. 0.0 2.9947E-3 13 0.0 0. CHLORINE
MATERIAL 19. 0.0 0.862 14. 0.0 0. POTASSIU
MATERIAL 15. 0.0 2.2 16. 0.0 0. PHOSPHO
MATERIAL 30. 0.0 7.133 17. 0.0 0. ZINC
MATERIAL 20. 0.0 1.55 21. 0.0 0. CALCIUM
MATERIAL 0.0 0.0 0.3 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
MAT-PROP 0.0 3.50 75.3 18. 0. 0.
STERNHEI 3.4708 0.2261 2.8001 0.08588 3.5353 0. 18
The same example, name based:
MATERIAL 1. 0.0 8.3748E-5 0.0 0.0 1. HYDROGEN
MATERIAL 6. 0.0 2.265 0.0 0.0 0. CARBON
MATERIAL 7. 0.0 0.0011653 0.0 0.0 0. NITROGEN
MATERIAL 8. 0.0 0.001429 0.0 0.0 0. OXYGEN
MATERIAL 12. 0.0 1.74 0.0 0.0 0. MAGNESIU
MATERIAL 11. 0.0 0.971 0.0 0.0 0. SODIUM
MATERIAL 26. 0.0 7.874 0.0 0.0 0. IRON
MATERIAL 16. 0.0 2.0 0.0 0.0 0. SULFUR
MATERIAL 17. 0.0 2.9947E-3 0.0 0.0 0. CHLORINE
MATERIAL 19. 0.0 0.862 0.0 0.0 0. POTASSIU
MATERIAL 15. 0.0 2.2 0.0 0.0 0. PHOSPHO
MATERIAL 30. 0.0 7.133 0.0 0.0 0. ZINC
MATERIAL 20. 0.0 1.55 0.0 0.0 0. CALCIUM
MATERIAL 0.0 0.0 0.3 0.0 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 3.50 75.3 LUNG 0. 0.
STERNHEI 3.4708 0.2261 2.8001 0.08588 3.5353 0. LUNG
Example 3 (number based):
MATERIAL 6. 0.0 2.265 6. 0.0 0. CARBON
MATERIAL 7. 0.0 0.0011653 7. 0.0 0. NITROGEN
MATERIAL 8. 0.0 0.001429 8. 0.0 0. OXYGEN
MATERIAL 18. 0.0 1.662E-3 20. 0.0 0. ARGON
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
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
MAT-PROP 2.0 0.0 85.7 11.
STERNHEI 10.5961 1.7418 4.2759 0.10914 3.3994 0. 11
The same example, name based:
MATERIAL 6. 0.0 2.265 0.0 0.0 0. CARBON
MATERIAL 7. 0.0 0.0011653 0.0 0.0 0. NITROGEN
MATERIAL 8. 0.0 0.001429 0.0 0.0 0. OXYGEN
MATERIAL 18. 0.0 1.662E-3 0.0 0.0 0. ARGON
MATERIAL 0.0 0.0 0.001205 0.0 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 0.0 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 AIR2
STERNHEI 10.5961 1.7418 4.2759 0.10914 3.3994 0. AIR2
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