[Gate-users] Alpha particle not depositing energy

[Amy Meldrum]

Gate Users,

I am still trying to solve my problem of not being able to generate optical
photons with an alpha source and a scintillator. When I run my current
simulation with a gamma source starting right next to my scintillator, I
generate optical photons no problem. However, when I change to an alpha
source, it seems that my alpha particles are not depositing any energy as
they travel? As my run progresses, I get messages like:


***********************************************************************************************
* G4Track Information:     Particle = alpha,  Track ID = 1, Parent ID = 0
***********************************************************************************************

Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume
 ProcName
   0          0         0         25          5.3         0             0
           0       scanner_phys InitStep
   1          0         0         25          5.3         0            0.01
        0.01  LayerOne_phys Transportation
   2          0         0         -25         5.3         0             50
           50      pmt_phys      Transportation
   3          0         0         -35         5.3         0             10
           60     scanner_phys Transportation
   4          0         0         -50         5.3         0             15
           75      world_phys    Transportation
   5          0         0         -200       5.3         0             150
         225     OutOFWorld  Transportation


LayerOne is my scintillating volume, LSO.

The physics I have included are:
hMultipleScattering alpha (sometimes included, it does not change the fact
that no energy gets deposited)
IonInelastic
G4LEAlphaInelastic alpha
Scintillation alpha
OpticalRayleigh
OpticalAbsorption
OpticalBoundary


Has anyone worked with an alpha source at all before? Is there a key
physics process I am missing? Alphas should deposit all of their energy
within a few interactions, and should most definitely be stopped by my
scintillator layer, a 5cm cube of LSO.

Any help is greatly appreciated. I have been struggling with this for quite
some time.

Thank you,

-Amy
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