[Gate-users] Ion source - timestamp problem Gate 6.0.1

[Mercedes Rodriguez]

Dear Gate Users,

I'm trying to use an ion source (18F, 22Na or 15O) for a PETscanner 
geometry and the simulation provides strange results for the timestamps. 
For instance, I run the simulation using 18F, setTimeSlice=60 s and the 
time histogram for coincidence events goes from 0 to ~100000 s, 
following an exponential decay. No randoms and no scattered events are 
produced. My guess is that time sampling is incorrect when using an ion 
source.

When I run the simulation for e+ that have an 18F energy spectrum (and 
the corresponding half life) I obtain randoms and scattered events 
different from zero and the time histogram is what I expect, flat from 0 
to 60 s. I'm attaching a pdf file with a couple of graphs for 18F (ion 
source and e+), Ao=4e5 Bq, TimeSlice=60s.

Any idea of what could be happening?

Regards.
Mercedes

-- 
Mercedes Rodriguez Villafuerte, Ph.D.
Visiting Professor, Cherry's Lab
BME, UC Davis
451 Health Sciences Drive, GBSF 2505
Davis, CA 95616

Tel: 530-752-6387

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