[Gate-users] Yttrium 90 Source

[André Rodrigues Diogo]

Dear Gate users,

I have been having an issue with the fastY90 source. I’m using Gate 8.0.
I have been trying to simulate Y-90 as a positron emitter through the fastY90 source but the positron range I have obtained seems to be about half of the theoretical range (0.95mm as opposed to ~2mm)

Does anyone know why this is happening? If this is because of the source not having the right energy distribution for the positrons? And how to solve this?

I have checked many times the physics list and everything else in my files but I can’t find anything wrong.

I have defined my source as:

###### Yttrium Source -> fastY90
/gate/source/addSource						Yttrium90	fastY90
/gate/source/Yttrium90/useDefaultHalfLife		
/gate/source/Yttrium90/setActivity				2500000000.0	becquerel
/gate/source/Yttrium90/gps/energytype 			Mono
/gate/source/Yttrium90/gps/monoenergy 		0. MeV
/gate/source/Yttrium90/setMinBremEnergy		50 keV
/gate/source/Yttrium90/setPositronProbability  	0.00003186

I have also tried to define the Y-90 as an ion source but in Geant4 it is implemented as a pure beta emitter and doesn’t include positrons.


Many thanks,
André Diogo