FLUKA: OPT-PROP
Previous Index Next
OPT-PROP
defines optical properties of specified materials
See also OPT-PROD, Chap. 12}.
For SDUM
= WV-LIMIT: defines wavelength range for optical photon transport
WHAT(1)
> 0.0: minimum wavelength (in cm) for optical photon transport
= 0.0: ignored
< 0.0: resets to default
Default
: 2.50E-5 (250 nm)
WHAT(2)
> 0.0: central wavelength (in cm) for optical photon transport
= 0.0: ignored
< 0.0: resets to default
Default
: 5.89E-5 ((589 nm, Na D line)
WHAT(3)
> 0.0: maximum wavelength (in cm) for optical photon transport
= 0.0: ignored
< 0.0: resets to default
Default
: 6.00E-5 (600 nm)
WHAT(4-6): assignment to materials, see below
SDUM
= WV-LIMIT
For SDUM
= OM-LIMIT: defines angular frequency range for optical photon transport
WHAT(1)
> 0.0: minimum angular frequency for optical photon transport
omega = 2pi x frequency (in rad/s)
= 0.0: ignored
< 0.0: resets to default
Default
: 3.14E15 rad/s (corresponding to 600 nm)
WHAT(2)
> 0.0: central angular frequency for optical photon transport
omega = 2pi x frequency (in rad/s)
= 0.0: ignored
< 0.0: resets to default
Default
: 3.20E15 rad/s (corresponding to 589 nm, Na D line)
WHAT(3)
> 0.0: maximum angular frequency for optical photon transport
omega = 2pi x frequency (in rad/s)
= 0.0: ignored
< 0.0: resets to default
Default
: 7.53E15 rad/s (corresponding to 250 nm)
WHAT(4-6): assignment to materials, see below
SDUM
= OM-LIMIT
For SDUM
= RESET: all optical properties are zeroed
WHAT(1-3) = no meaning
WHAT(4-6): assignment to materials, see below
SDUM
= RESET
For SDUM
= METAL: flag the material as a metal
WHAT(1)
= 1st optical property (not used at the moment)
WHAT(2)
= 2nd optical property (not used at the moment)
WHAT(3)
= 3rd optical property: (1-r), where r is the reflectivity
index at the central wavelength (or at the central angular
frequency, depending on which one of the two quantities has been
defined). See also Note 2
Default
= 0.0
WHAT(4-6): assignment to materials, see below
SDUM
= METAL
For SDUM
= blank:
WHAT(1)
= 1st optical property: refraction index at the central
wavelength (or at the central angular frequency, depending
on which one of the two quantities has been defined)
< -99: forces to use user routine RFRNDX (see Note 1)
Default
= 1.0
WHAT(2)
= 2nd optical property: absorption coefficient (cm^-1) at
the central wavelength (or at the central angular
frequency, depending on which one of the two quantities has
been defined)
< -99: forces to use user routine ABSCFF (see Note 1)
Default
= 0.0
WHAT(3)
= 3rd optical property: diffusion coefficient (cm^-1) at
the central wavelength (or at the central angular
frequency, depending on which one of the two quantities has
been defined)
< -99: forces to use user routine DFFCFF (see Note 1)
Default
= 0.0
WHAT(4-6): assignment to materials, see below
SDUM
= blank
For SDUM
containing &1 (resp. &2) (resp. &3):
WHAT(1)
= 4th (resp. 7th) (resp. 10th) optical property of the material
(derivatives of the refraction index, see Note 2 below)
Default
= 0.0
WHAT(2)
= 5th (resp. 8th) (resp. 11th) optical property of the material
(derivatives of the absorption coefficient, see Note 2 below)
Default
= 0.0
WHAT(3)
= 6th (resp. 9th) (resp. 12th) optical property of the material
(derivatives of the diffusion coefficient, see Note 2 below)
Default
= 0.0
WHAT(4-6): assignment to materials, see below
SDUM
= &1, &2 or &3
For all previous SDUM
's:
WHAT(4)
= lower bound of the indices of materials to which the indicated
optical properties refer
From material WHAT(4)
...
Default
= 3
WHAT(5)
= upper bound of the indices of materials to which the indicated
optical properties refer
...To material WHAT(5)
...
Default
= WHAT(4)
WHAT(6)
= ... in step of WHAT(6)
Default
= 1
For SDUM
= SENSITIV: sets up the optical photon detection sensitivity parameters
(See also SDUM
= WV-SENSI, SDUM
= OM-SENSI, Note 3 below and the examples in
Chap. 12})
WHAT(1)
= 0th photon sensitivity parameter
< -99: forces to use user routine QUEFFC (see Note 1)
WHAT(2)
= 1st optical property (not used at the moment)
WHAT(3)
= 2nd optical property (not used at the moment)
WHAT(4)
= 3rd optical property: (1-r), where r is the reflectivity
index at the central wavelength (or at the central angular
frequency, depending on which one of the two quantities has been
defined). See also Note 2
Default
= 0.0
WHAT(5)
= maximum optical photon sensitivity over the allowed range (must be
consistent with the previous values). It can be overestimated.
Default
= 1.0
WHAT(6)
: not used
SDUM
= SENSITIV
For SDUM
= WV-SENSI: setup the wavelength of the optical photon sensitivity
(See also SDUM
= SENSITIV, SDUM
= OM-SENSI and Note 3 below)
WHAT(1)
> 0.0: minimum wavelength (in cm) for optical photon sensitivity
= 0.0: ignored
< 0.0: resets to default
Default
= 2.5 x 1.0E-5 (250 nm)
WHAT(2)
> 0.0: central wavelength (in cm) for optical photon sensitivity
= 0.0: ignored
< 0.0: resets to default
Default
= 5.89 x 1.0E-5 (589 nm, Na D line)
WHAT(3)
> 0.0: maximum wavelength (in cm) for optical photon sensitivity
= 0.0: ignored
< 0.0: resets to default
Default
= 6.0 x 1.0E-5 (600 nm)
WHAT(4)
-WHAT(6)
: not used
SDUM
= WV-SENSI
For SDUM
= OM-SENSI: setup the angular frequency of the optical photon sensitivity
(See also SDUM
= SENSITIV, SDUM
= WV-SENSI and Note 3 below)
WHAT(1)
> 0.0: minimum angular frequency for optical photon sensitivity
omega = 2 pi x frequency in rad/s
= 0.0: ignored
< 0.0: resets to default
Default
= 3.14E15 rad/s (corresponding to 600 nm)
WHAT(2)
> 0.0: central angular frequency for optical photon sensitivity
omega = 2 pi x frequency in rad/s
= 0.0: ignored
< 0.0: resets to default
Default
= 3.20E15 rad/s (corresponding to 589 nm, Na D line)
WHAT(3)
> 0.0: maximum angular frequency for optical photon sensitivity
omega = 2 pi x frequency in rad/s
Default
= 7.53E15 rad/s (corresponding to 250 nm)
WHAT(4)
-WHAT(6)
: not used
SDUM
= OM-SENSI
For SDUM
= SPEC-BDX: flags special boundary crossings for optical photons
At the selected boundary crossings special user-defined properties
are defined by means of the user routine OPHBDX (see Note 1 below).
A maximum of 40 boundaries can be flagged by issuing option OPT-PROP with
SDUM
= SPEC-BDX as many times as needed.
WHAT(1)
>= 1.0: special boundary treatment activated for the n-th+1 boundary
= 0.0: ignored
=< -1.0: special boundary treatment deactivated for the n-th+1 boundary
WHAT(2)
= One of the two regions defining the n-th+1 boundary
WHAT(3)
= The other region defining the n-th+1 boundary
WHAT(4)
>= 1.0: special boundary treatment activated for the n-th+2 boundary
= 0.0: ignored
=< -1.0: special boundary treatment deactivated for the n-th+2 boundary
WHAT(5)
= One of the two regions defining the n-th+2 boundary
WHAT(6)
= The other region defining the n-th+2 boundary
SDUM
= SPEC-BDX
Default
(option OPT-PROP not given): no optical photon transport
Notes:
1) The optional user routines concerning optical photons are:
* RFRNDX: to specify a refraction index as a function of wavelength,
frequency or energy. Activated by setting WHAT(1)
< -99 when
SDUM
= blank.
* ABSCFF: to specify an absorption coefficient as a function of wavelength,
frequency or energy. This is activated by setting WHAT(2)
< -99 when
SDUM
= blank.
* DFFCFF: to specify a diffusion coefficient as a function of wavelength,
frequency or energy. Activated by setting WHAT(3)
< -99 when
SDUM
= blank.
* RFLCTV: to specify the reflectivity of a material.
This can be activated with SDUM
= METAL and WHAT(3)
< -99
* OPHBDX: to set optical properties of a boundary surface. The call is
activated with SDUM
= SPEC-BDX
* FRGHNS: to set a possible degree of surface roughness, in order to have
both diffusive and specular reflectivity from a given material surface
* QUEFFC: to introduce Quantum efficiency. This is activated by setting
the 0-th photon sensitivity parameter to a value < -99 with
SDUM
= SENSITIV .
2) The 9 material properties input by the user with SDUM
= &1, &2 and &3
are derivatives of order 1 to 3 of the three basic quantities which are
input with SDUM
= blank or SDUM
= METAL. The three basic quantities and
their derivatives are used to perform three series expansions centred
on the selected central wavelength (if SDUM
= WV-LIMIT has been used
for the material concerned) or on the selected central angular frequency
(if SDUM
= OM-LIMIT has been used). The variable x used in the expansion
is adimensional:
x = ( lambda - lambda_central ) / lambda_central or
x = ( omega - omega_central ) / omega_central
3) The three basic quantities are:
If SDUM
= blank: 1) refraction index n_refr
2) absorption coefficient mu_abs
3) diffusion coefficient mu_diff
If SDUM
= METAL: 1) (not implemented yet)
2) (not implemented yet),
3) (1-r) (r = reflectivity index)
The 4th, 5th, 6th material properties are:
d n_refr/ dx, d mu_abs/dx, d mu_diff/dx
the 7th, 8th, 9th material properties are:
d2 n_refr/ dx^2, d2 mu_abs/dx^2, d2 mu_diff/dx^2
the 10th, 11th, 12th material properties are:
d3 n_refr/ dx^3, d3 mu_abs/dx^3, d3 mu_diff/dx^3
4) SDUM
= SENSITIV can be used to set the quantum efficiency as a
function of photon energy OVERALL through the problem and it is not
material/region dependent.
The reason is that it is applied "a priori" at photon generation time.
If a quantum efficiency curve is to be introduced AT DETECTION,
then a weighting user routine should be used, such as FLUSCW or COMSCW.
It is advantageous to reduce computer time avoiding to generate and
transport a photon which would have a significant probability to remain
undetected.
5) The optical photon sensitivity parameters are:
epsilon(0), d epsilon/dx, d2 epsilon/dx2, d3 epsilon/dx3 where x is:
x = (lambda - lambda_central)/lambda_central
or
x = (omega - omega_central)/omega_central
Example 1:
OPT-PROP 3.E15 6.E15 7.E15 6.0 18.0 3. OM-LIMIT
MAT-PROP 1.0 0.0 0.0 6.0 18.0 6. USERDIRE
Example 2:
OPT-PROP 0.0 0.0 0.32 11.0 0.0 0. METAL
Example 3:
MATERIAL 1.0 0.0 .0000899 3.0 0.0 1. HYDROGEN
MATERIAL 8.0 0.0 0.00143 5.0 0.0 0. OXYGEN
MATERIAL 0.0 0.0 1.0 21.0 0.0 0. WATER
COMPOUND 2.0 3.0 1.0 5.0 0.0 0. WATER
OPT-PROP 3.E-5 5.89E-5 6.E-5 21.0 0.0 0. WV-LIMIT
OPT-PROP 1.33299 0.0013 1.22E-5 21.0 0.0 0.
Previous Index Next
