[Gate-users] Potential bug in ring repeaters in GATE

[Zhengzhi Liu]

It looks like ring repeaters does not like twice, other times of
repartition seem to work fine.

On Sat, Jan 25, 2020 at 3:53 PM Zhengzhi Liu <zliu36 at stanford.edu> wrote:

> Dear GATE developers and users,
>
> I recently came across a weird situation in GATE and have spent a few days
> on it, but still could not figure it out why. Here is the problem:
>
> In benchPET
> <https://github.com/OpenGATE/Gate/blob/develop/benchmarks/benchPET/camera.mac> and
> GateContrib
> <https://github.com/OpenGATE/GateContrib/blob/master/imaging/PET/PET_CylindricalPET_System.mac>,
> the original code works fine, but soon as I change the times in the ring
> repeater to 2 in the following code, there will be no coincidence event
> recorded:
>
> /gate/head/repeaters/insert                          ring
> /gate/head/ring/setRepeatNumber               4
>
> I did check all the details and nothing seems to have been changed
> fundamentally, except that there are fewer detectors in the transaxial
> plane. Even so, there are still two detector panels facing each other as
> shown in the attached figure (benchPET_ring_repeaters_2.png). Each detector
> panel has registered many singles as shown in the root plot
> (hits_on_detectors.png). However, there was no coincidence event
> registered, not event a single coincidence event. Originally I thought it
> might be due to low geometrical sensitivity but after moving these detector
> panels closer to each other and increasing simulation time, there was still
> no coincidence event registered.
>
> This phenomenon happens in both PET simulation cases mentioned above and
> other PET simulations. Has anyone come across this problem before? Is this
> a bug or simply my mistake?  Please give me any thoughts or help.
>
> Thank you very much,
> Sincere regards.
>
> Zhengzhi
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20200125/40fc4829/attachment.html>