[Gate-users] system choice for energy centroid

Devin VanElburg vanelbud at tbh.net
Wed Jun 3 20:52:30 CEST 2015


Here is what I get with the describe command:

Idle> /gate/systems/cylindricalPET/describe                             
   

GATE object:        'systems/cylindricalPET'
Components:    

GATE object:        'systems/cylindricalPET/base'
Attached to volume: cylindricalPET
Nb of children:       1

    GATE object:        'systems/cylindricalPET/rsector'
    Attached to volume: headblock
    Nb of children:       1

        GATE object:        'systems/cylindricalPET/module'
        Attached to volume: crystalboard
        Nb of children:       1

            GATE object:        'systems/cylindricalPET/submodule'
            Attached to volume: ---
            Nb of children:       1

                GATE object:        'systems/cylindricalPET/crystal'
                Attached to volume: crystal
                Nb of children:       4

                    GATE object:        'systems/cylindricalPET/layer0'
                    Attached to volume: lyso
                    Nb of children:       0

                    GATE object:        'systems/cylindricalPET/layer1'
                    Attached to volume: ---
                    Nb of children:       0

                    GATE object:        'systems/cylindricalPET/layer2'
                    Attached to volume: ---
                    Nb of children:       0

                    GATE object:        'systems/cylindricalPET/layer3'
                    Attached to volume: ---
                    Nb of children:       0
geometrical design type: 1
ring diameter: 8.014 cm 
rsector axial pitch: 0 fm 
rsector azimuthal pitch: 180 degree
rsector tangential size: 5.766 cm 
rsector axial size: 5.766 cm 
module axial size: 5.766 cm 
module tangential size: 5.766 cm 
module axial pitch: 0 fm 
module tangential pitch: 0 fm 
submodule axial size: 5.766 cm 
submodule tangential size: 5.766 cm 
submodule axial pitch: 0 fm 
submodule tangential pitch: 0 fm 
crystal radial size: 1.3 cm 
crystal axial size: 2.32 mm 
crystal tangential size: 2.32 mm 
crystal axial pitch: 2.4 mm 
crystal tangential pitch: 2.4 mm 
layer0 radial size: 1.3 cm 
in layer0 interaction length: 6.5 mm 
Axial nb of rsectors: 1
Azimuthal nb of rsectors: 2
Axial nb of modules: 1
Tangential nb of modules: 1
Axial nb of submodules: 1
Tangential nb of submodules: 1
Axial nb of crystals: 24
Tangential nb of crystals: 24
Radial nb of layers: 1
Idle> 


Regards,
Devin Van Elburg

------------------------
Physics w/ c/ Biomedical Physics
Lakehead University


>>> Marc Chamberland  06/03/15 11:46 AM >>>
I had a quick look at the source code and can’t see anything obvious.
However, it was recently re-written, so there might still be bugs in it.
>From my limited experience and knowledge, I’d stick with the cylindrical
PET system for now. Also, can you post what you get when you do:

/gate/systems/cylindricalPET/describe

after you’ve defined your entire system? No idea if it’ll be of any
help, but when I run into bugs like this, I throw everything at the wall
and see what sticks, so to speak. 

Marc



> On Jun 3, 2015, at 11:14, Devin VanElburg  wrote:
> 
> Thanks for your input Marc!
> 
> I'm not particularly comfortable with C++, so I don't want to be
poking around at the code. There must be something I'm missing. I'll
keep plugging away, and hopefully I find out what's causing my issue.
> 
> Devin Van Elburg
> 
> ------------------------
> Physics w/ c/ Biomedical Physics
> Lakehead University
> 
> 
> >>> Marc Chamberland 06/03/15 10:16 AM >>>
> Thanks, Devin. That’s much more clear.
> 
> I’ve never used anything but the default policy. However at first
sight, it looks like you’re doing everything right. Maybe someone with
more experience can chime in, but it’s also possible this is a bug. If
you’re comfortable with C++, I’d suggest you take a quick look at the
area of the code where the error message is produced and see if anything
jumps at you.
> 
> Marc
> 
> 
>> On Jun 3, 2015, >> I'll try and explain a little better what I'm trying to do. I have
defined my system as a PETscanner and attached the daughter volumes as
follows:
>> 
>> /gate/systems/PETscanner/level1/attach headblock
>> /gate/systems/PETscanner/level2/attach crystalboard
>> /gate/systems/PETscanner/level3/attach crystal
>> /gate/systems/PETscanner/layer0/attach lyso
>> /gate/lyso/attachCrystalSD
>> 
>> where 'crystal' is repeated as a cubicArray (24x24) and 'headblock'
is repeated twice with a ring repeater. I now have two opposing lyso
crystals with the attached CrystalSD. When using the default readout
policy:
>> 
>> /gate/digitizer/Singles/readout/setPolicy TakeEnergyWinner
>> 
>> My simulation runs fine, and the root output I receive is expected
(511keV peak as I am using a Na-22 source for positron annihilation) for
both Singles and Coincidences. However, when I try:
>> 
>> /gate/digitizer/Singles/readout/setPolicy TakeEnergyCentroid
>> 
>> I get a break with the following message:
>> 
>> [systems/PETscanner::FindComponent]:
>>     Could not find the request system component 'crystal'!
>> 
>> -------- EEEE ------- G4Exception-START -------- EEEE -------
>> *** G4Exception : ProcessPulseList
>>       issued by : GateReadout::ProcessPulseList
>> Failed to get the array component corresponding to the crystal.
Abort.
>> 
>> *** Fatal Exception *** core dump ***
>> -------- EEEE -------- G4Exception-END --------- EEEE -------
>> 
>> 
>> *** G4Exception: Aborting execution ***
>> Aborted (core dumped)
>> 
>> 
>> What I take from this is that I need to use a system that I can
attach a volume to a so-called 'crystal' level. I've been playing with
cylindricalPET and redefined my system as follows:
>> 
>> /gate/systems/cylindricalPET/rsector/attach headblock
>> /gate/systems/cylindricalPET/module/attach crystalboard
>> /gate/systems/cylindricalPET/crystal/attach crystal
>> /gate/systems/cylindricalPET/layer0/attach lyso
>> /gate/lyso/attachCrystalSD
>> 
>> that way, I have attached my 'crystal' volume to a 'crystal' level in
the system hierarchy as I assume the error message suggested. Even
still, I get the break segmentation violation. I also get the same error
when switching to TakeEnergyCentroid for the cylindricalPET example that
GATE supplies. The wiki says to ensure the Depth is taken just above the
crystal, which I did. In fact I tried running it with the depth at all
levels and they all failed. I'm at a loss, I can't seem to get the
TakeEnergyCentroid policy to work despite my best efforts!
>> 
>> By the way, ignore my comment with my previous email concerning the
number of plates with a ring repeater. That was a readout depth issue
and it's working now.
>> 
>> I'd appreciate any help I can get here!
>> 
>> Regards,
>> Devin Van Elburg
>> 
>> ------------------------
>> Physics w/ c/ Biomedical Physics
>> Lakehead University
>> 
>> 
>> 
>> 
>> >>> Marc Chamberland 06/02/15 5:00 PM >>>
>> Hi Devin,
>> 
>> I’m not sure I understand what you’re trying to do and what failed to
work. Can you provide more details?
>> 
>> Also, did you attach a crystalSD to your plates, as outlined here:
http://wiki.opengatecollaboration.org/index.php/Users_Guide_V7.1:Attaching_the_sensitive_detectors#The_crystalSD
>> 
>> Cheers,
>> Marc
>> 
>> 
>> 
>> __________________________
>> 
>> Marc Chamberland, PhD
>> Department of Physics
>> Carleton University
>> Ottawa (ON)
>> 
>>> On Jun 2, 2015, at 16:49, Devin VanElburg  wrote:
>>> 
>>> Hello gate users,
>>> 
>>> I am simulating a PET system with two plates. I would like to use
the takeEnergyCentroid option for the digitizer's readout. However, I
need to attach a volume to a 'crystal' of a system (according to the
error message I keep getting). Thus a PETscanner system cannot work
since it uses level1-4 and layers for system attachment. The I tried a
cylindricalPET system with a ring repeater of 2, and that also didn't
work. Interestingly, cylindricalPET works for a 4+ plate ring system,
buthe ring repeat number changed). Can anyone offer any insight as to what
I should do?
>>> 
>>> Regards,
>>> Devin Van Elburg
>>> 
>>> ------------------------
>>> Physics w/ c/ Biomedical Physics
>>> Lakehead University
>>> _______________________________________________
>>> Gate-users mailing list
>>> Gate-users at lists.opengatecollaboration.org
>>> http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
>> 
> 


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