I’m working on the reproduction of a calibration test with a Am-241 source. The source is a small sphere inside a plexiglass holder.
I generate the ions through GPS:
# Source: Americium-241 (Am-241)
/gps/particle ion
/gps/ion 95 241 0 0
/grdm/nucleusLimits 237 241 93 95 # Limited to Np-237
# Set the kinetic energy of the ion to 0 keV
/gps/energy 0 eV
/gps/pos/type Volume
/gps/pos/shape Sphere
/gps/pos/centre 12.28 -2. -18.37 mm
/gps/pos/radius 0.5 mm
/gps/ang/type iso
However, when looking directly to what comes out to a sensitive detector used to check the radioactive decay, what I found are events like these:
Why not just simulate a 59.541 gamma source instead?
You could keep the simulation as is but do something like this to remove the decay time of the Am241 from the timestamp. Lastly, you will get the products since the decay will impart kinetic energy to the Np237 and alpha particles. You should just filter those out in your sensitive detector by checking the particle type.
I’ve conducted some tests both on version 10.4.3 and 11.2.1, looking at the decay products of the Am241.
V 10.4.3
Limiting its chain at the Am-241 I obtained the Np237[59.541] with a probability of 97.90%, higher than the expected one of 84.6%.
Limiting its chain at the Np-237 the probability it’s almost the same, at 96.90%.
This let me think that there is some issue in how the decay chain is built.
V 11.2.1
Doing the same test I obtained the probability of 97.50%, suggesting that the problem in v10.4.3 is still there.
At this point my main strategy will be to set up through GPS a macro to simulate correctly the decay spectrum of the Americium taking the probabilities from reference table at least of the Am241 and Np237 which we see in the experimental spectrum of our detector.
