Energy spectrum from radioisotope decay

Dear Fluka experts,

currently i am trying to simulate scintillation detectors (LaBr3, NaI) to extract the energy deposition related to radiation of different Isotopes. It is an Event-by-event simulation.When simulating a simple point source with photons (622keV) I get great results of the simulations:

But when changing the point source into an Isotope (Cs-137) I won’t get any results out of it in the second column:

In the attachment i send both input files (simple point source & Isotope Cs-137).
Is there something wrong in the Cs-137 input file? What can be changed? Or how am i be able to get the energy spectrum of isotopes?

Thanks in advance
Moritz Ganter

simple_point_source.inp (3.6 KB)
Isotope.inp (3.6 KB)

Unfortunately, @moritz, the scoring of your choice (EVENTDAT) cannot be linked to the radioactive decay radiation by means of the dedicated DCYSCORE card, which applies to several other scoring types instead. I’d suggest you to adopt EVENTBIN by region and enable it to score the electromagnetic radiation coming from the radioisotope decay by means of the aforementioned DCYSCORE in Semi-Analogue mode (WHAT(1) = -1.0).

Dear Mr. Cerutti,

thanks for your answer. I tried to implement your suggestions into the input-file. This is a part of the results I got after running the simulation:

Are the results correct? And how am I able to extract the energy spectrum out of the asc.-file? Do i have to implement an own user-routine?
Sry, for all of these questions, i am kind of new to FLUKA and not that experienced with it.
In the attachment is the input-file with the suggestions you gave me.

Isotope.inp (3.7 KB)

Thanks a lot in advance

There are several issues in your input file.
First, you left an EVENTDAT card inside, conflicting with the output unit (22) of the suggested EVENTBIN card.
Then, in the latter, you asked to score in your DETECTOR region three times.
(Also, there is no point in limiting the scoring to EM-ENRGY, what I meant in my previous post is that the deposited ENERGY will come from electromagnetic particles originated by the isotope decay).
Avoid unjustified biasing and threshold adjustment in the RADDECAY card, which you should just use to activate semi-analogue decay.
You selected in BEAMPOS a volumetric distribution for your radioactive source, over a sphere of 1 mm radius, so I do not see the point for the annular request in the BEAM card, where in addition the isotropic choice is meaningless for an ISOTOPE, which is at rest.
The produced EVENTBIN output will be a human readable sequence of energy deposition values [GeV] in your detector, such as

that is available for any kind of analysis of your own (including spectrum generation), with no need for FLUKA user routines.
Take care

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