From: Paolo MAESTRO (paolo.maestro@pi.infn.it)
Date: Sun Dec 04 2005 - 05:29:21 CET
Hi fluka developers,
I would like to simulate transition radiation in a plastic
foam with holes punched, in which Xenon-Methane filled proportional tubes
are inserted. According to some experimental measurements
(P.J. Boyle et al., Proc. of 28th ICRC, 2003),
TR photons with an energy distributions in the range 1-100 keV
are expected to be produced in the foam radiatior.
I tried to switch on Trasition Radiation production and propagation
in my simulation program with the following cards:
********************************************************************************
* Polyethilene foam (Ethafoam) C2H4
MATERIAL 0. 0. 0.035 30.0 0. 0.
POLYETHY
COMPOUND 2.0 6.0 4.0 3.0 0.0 0.0
POLYETHY
* Metano CH4
MATERIAL 0. 0. 6.6715E-4 31.0 0. 0.
METHAN
COMPOUND 1.0 6.0 4.0 3.0 0. 0.
METHAN
* 95% XE 5% CH4 mixture
MATERIAL 0. 0. 5.25E-3 32.0 0. 0.
XECH4
COMPOUND -0.9934 11.0 -6.6E-3 31.0 0. 0.
XECH4
* gas XECH4 and CH4 at 1 atm pressure
MAT-PROP 1.0 0.0 0.0 31.0 32.0 1.0
* MYLAR = Polyethylene terephthalate C10H8O4
MATERIAL 0. 0. 1.4 33.0 0. 0.
MYLAR
COMPOUND 10.0 6.0 8.0 3.0 4.0 8.0
MYLAR
* 1 keV 100 keV
OPT-PROD 1E-6 100E-6 0. 30.0 TR-RADIA
OPT-PROP 1.5193E18 1.5193E19 1.5193E20 30.0 OM-LIMIT
OPT-PROP 1.5193E18 1.5193E19 1.5193E20 32.0 33.0 1.0 OM-LIMIT
OPT-PROP 1.0 0.0623 0.011 30.0
OPT-PROP 1.0 0.1054 0.00183 32.0
OPT-PROP 1.0 4.41 0.4634 33.0
*********************************************************************************
but at runtime I got no result, e.g. I modified the mgdraw.f routine to
print out optical photons tracks and energy deposits, but it seems that no optical
photons are generated.
In the OPT-PROP cards with SDUM=OM-LIMIT I calculated the omega
corresponding to energy 1, 10, 100 keV.
In OPT-PROP with SDUM=blank, I filled WHAT(2) and WHAT(3) with the
linear attenuation coefficients (cm^-1) respectively for photoelectric
absorption and Compton+Rayleigh scattering, at 10 keV. At this energy the refractive
index WHAT(1) can be taken equals to 1 for the three materials.
I wonder if transition radiation generation in Fluka is intended to
address such kind of problem and, in case, if TR X-rays are handled as
optical photons (fluka particle id=-1) or photons (fluka particle id=7).
Many thanks for your help.
Best regards
Paolo Maestro
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