I’m very new at FLUKA and trying to build an RTG simulation with a cylindrical radioisotope source. I was wondering, is it possible to simulate/calculate the heating effects of a gamma beam source and heating transfer? Or is ENERGY option at USRBIN is enough to indicate the heating effect?
Also, I am having troubles with adjusting the beam source, DOSE-EQ values for the specified beam that I use seems low, how should I adjust the intensity of a radiation source? Is adjusting the volume of the cylindrical beam is enouh-gh or should I use other cards to correctly simulate a cylindrical gamma source?
With FLUKA, as you noticed, you can get energy deposition with a cartesian or cylindrical USRBIN -expressed in GeV/cm3 per unit primary weight (your primary particle). Then you should normalize your results multiplying by the photon intensity (rate). To get e.g. a power deposited per cm3, (W/cm3) you need to convert GeV to J (1.6022e-10).
For what concerns the photon source definition (not a radioisotope), you need the following cards: BEAM to define your primary beam – particles (photons) and their energy etc., BEAMPOS where you specify a cylindrical source (Type:CYLI-VOL) – with all dimensions Rin/Rout, Hin/Hout and the second BEAMPOS card with a center coordinates of your cylindrical source.
Normalization, as mentioned before, is done at the last step by multiplying your results by the photon intensity/rate.
If instead you want to define a radioisotope uniformly distributed in a cylinder, you need a BEAM card with ISOTOPE (particle) and HI-PROPE card with A,Z of your isotope, as well as two BEAMPOS cards as explained above. A RADDECAY card is then needed to let it decay.
Let me know if you need further help or explanation.