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OPT-PROD


    requests and controls production of Cherenkov, Transition and Scintillation
    Radiation in specified materials

    See also OPT-PROP, Chap. 12}.

  For 
SDUM
= CERE-OFF: switches off Cherenkov production WHAT(1-3): not used WHAT(4-6): assignment to materials, see below
SDUM
= CERE-OFF For
SDUM
= TRD-OFF: switches off Transition Radiation production WHAT(1-3): not used WHAT(4-6): assignment to materials, see below
SDUM
= TRD-OFF For
SDUM
= SCIN-OFF: switches off Scintillation light production WHAT(1-3): not used WHAT(4-6): assignment to materials, see below
SDUM
= SCIN-OFF For
SDUM
= CERENKOV: switches on Cherenkov production and defines photon energy range
WHAT(1)
= minimum Cherenkov photon emission energy in GeV
Default
: 2.07E-9 GeV (2.07 eV, corresponding to 600 nm)
WHAT(2)
= maximum Cherenkov photon emission energy in GeV
Default
: 4.96E-9 GeV (4.96 eV, corresponding to 250 nm)
WHAT(3)
: not used WHAT(4-6): assignment to materials, see below
SDUM
= CERENKOV For
SDUM
= CEREN-WV: switches on Cherenkov production and defines photon wavelength range
WHAT(1)
= minimum Cherenkov photon emission wavelength in cm
Default
: 2.50E-5 cm (250 nm, or 1.2E6 GHz)
WHAT(2)
= maximum Cherenkov photon emission wavelength in cm
Default
: 6.00E-5 cm (600 nm, or 5.E5 GHz)
WHAT(3)
: not used WHAT(4-6): assignment to materials, see below
SDUM
= CEREN-WV For
SDUM
= CEREN-OM: switches on Cherenkov production and defines photon angular frequency range
WHAT(1)
= minimum Cherenkov photon angular frequency omega = 2 x pi x frequency (in rad/s)
Default
: 3.14E15 rad/s (corresponding to 600 nm)
WHAT(2)
= maximum Cherenkov photon angular frequency omega = 2 x pi x frequency (in rad/s)
Default
: 7.53E15 rad/s (corresponding to 250 nm)
WHAT(3)
: not used WHAT(4-6): assignment to materials, see below
SDUM
= CEREN-OM * Start_Devel_seq For
SDUM
= TR-RADIA: switches on Transition Radiation production and defines its energy range *** not yet implemented*****
WHAT(1)
= minimum TRD photon emission energy
WHAT(2)
= maximum TRD photon emission energy
WHAT(3)
: not used WHAT(4-6): assignment to materials, see below
SDUM
= TR-RADIA * End_Devel_seq For
SDUM
= SCINTILL: switches on Scintillation Light production and defines photon energy
WHAT(1)
= i-th scintillation photon emission energy in GeV (i_max =3, see Note 4)
WHAT(2)
> 0: fraction of energy loss going into i-th scintillation photon emission. =< -100: forces to use a user routine (see SPHSPC, USFSCI) >= -99.0 and =< 0.0: ignored
WHAT(3)
: time constant of scintillation light in seconds WHAT(4-6): assignment to materials, see below
SDUM
= SCINTILL For
SDUM
= SCINT-WV: switches on Scintillation Light production and defines photon wavelength
WHAT(1)
= i-th scintillation photon emission wavelength in cm (i_max =3, see Note 4)
Default
: 2.50E-5 cm (250 nm, or 1.2E6 GHz)
WHAT(2)
> 0: fraction of energy loss going into i-th scintillation photon emission =< -100: forces to use a user routine (see SPHSPC, USFSCI) >= -99.0 and =< 0.0: ignored
WHAT(3)
: time constant of scintillation light in seconds WHAT(4-6): assignment to materials, see below
SDUM
= SCINT-WV For
SDUM
= SCINT-OM: switches on Scintillation Light production and defines photon angular frequency range
WHAT(1)
= i-th scintillation photon emission angular frequency omega = 2 x pi x frequency (in rad/s), (i_max =3, see Note 4)
Default
: 3.14E15 rad/s (corresponding to 600 nm)
WHAT(2)
> 0: fraction of energy loss going into i-th scintillation photon emission =< -100: forces to use a user routine (see SPHSPC, USFSCI) >= -99.0 and =< 0.0: ignored
WHAT(3)
: time constant of scintillation light in seconds WHAT(4-6): assignment to materials, see below
SDUM
= SCINT-OM For all previous
SDUM
's:
WHAT(4)
= lower bound of the indices of materials in which the indicated Cherenkov, Scintillation or TRD photon emission range is defined From material
WHAT(4)
...
Default
= 3
WHAT(5)
= upper bound of the indices of materials in which the indicated Cherenkov or TRD photon emission range is defined ...To material
WHAT(5)
...
Default
=
WHAT(4)
WHAT(6)
= step length in assigning indices ...in step of
WHAT(6)
Default
= 1
Default
: (option OPT-PROD not given): no Cherenkov, scintillation or TRD photon production
Notes:
1) Optical photons such as those produced by Cherenkov effect are distinguished by their FLUKA name (OPTIPHOT) and by their FLUKA id number (-1), as shown in 5}. 2) To transport optical photons, it is necessary to define the optical properties of the relevant materials by means of option OPT-PROP. Users can also write their own routines USRMED (which is called at every step and at boundary crossings when activated with MAT-PROP) and FRGHNS (which defines surface roughness). 3) The energy/wavelength/frequency range as defined by OPT-PROD for Cherenkov photon production is not necessarily the same as that defined for transport by means of OPT-PROP. The default values, however, are the same. 4) In case of scintillation light, only monochromatic photons are considered for the moment, with a maximum of 3 different lines. The lines can be defined repeating i times the OPT-PROD card with
SDUM
= SCINTILL. The energy lost by ionizing particles is partially spent to produce optical photons, according to the fraction entered in what(2). The sum of what(2) for all OPT-PROD cards in a given material must be <1 (usually much less).
Example:
* Request production of Cherenkov photons with energies between 2 and 3 eV in
* materials 16, 17, 19 and 20, with wavelengths between 300 and 600 nm in
* materials 18, 20 and 22, and with frequencies between 0.5 and 1 million GHz
* in material 21
*...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+...
OPT-PROD 2.E-9 3.E-9 0.0 16.0 17.0 0. CERENKOV OPT-PROD 2.E-9 3.E-9 0.0 19.0 20.0 0. CERENKOV OPT-PROD 3.E-5 6.E-5 0.0 18.0 22.0 2. CEREN-WV OPT-PROD 3.14E15 6.28E15 0.0 21.0 0.0 0. CEREN-OM
* Optical photon transport requested between 300 and 500 nm for all materials
* with number between 16 and 21
OPT-PROP 3.E-5 5.E-5 6.E-5 16.0 22.0 0. WV-LIMIT
* User routine USRMED called when an optical photon is going to be transported
* in materials 17 and 21
MAT-PROP 1.0 0.0 0.0 17. 21. 4. USERDIRE

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