[Gate-users] Pixelated detectors (Lee, Sam (SAM LEE))

[Ricardo Capote]

Hi Sam Lee,

Here you have an example code that I use to simulate pixelated detectors:


# crystals.mac

##### Detector or Crystal Matrix Volume #####
/gate/SPECThead/daughters/name crystal
/gate/SPECThead/daughters/insert box
/gate/crystal/geometry/setXLength 10. mm
/gate/crystal/geometry/setYLength 110.1 mm
/gate/crystal/geometry/setZLength 146.9 mm
/gate/crystal/placement/setTranslation 0. 0. 0. mm
/gate/crystal/setMaterial Plastic
/gate/crystal/vis/setColor white
/gate/crystal/vis/forceWireframe

##### Individual Module #####
/gate/crystal/daughters/name module
/gate/crystal/daughters/insert box
/gate/module/geometry/setXLength 10. mm
/gate/module/geometry/setYLength 8.9 mm
/gate/module/geometry/setZLength 18.1 mm
/gate/module/placement/setTranslation 0. 0. 0. mm
/gate/module/setMaterial Plastic
/gate/module/vis/setColor green
/gate/module/vis/forceWireframe

##### Individual Crystal #####
/gate/module/daughters/name pixel
/gate/module/daughters/insert box
/gate/pixel/geometry/setXLength 10. mm
/gate/pixel/geometry/setYLength 2. mm
/gate/pixel/geometry/setZLength 2. mm
/gate/pixel/placement/setTranslation 0. 0. 0. mm
/gate/pixel/setMaterial NaI
/gate/pixel/vis/setColor blue
#/gate/pixel/vis/forceWireframe

## Repeat the crystals in an array 4x8
## (Create a complete module --> 32 crystals)
/gate/pixel/repeaters/insert cubicArray
/gate/pixel/cubicArray/setRepeatNumberX 1
/gate/pixel/cubicArray/setRepeatNumberY 4
/gate/pixel/cubicArray/setRepeatNumberZ 8
/gate/pixel/cubicArray/setRepeatVector 0. 2.3 2.3 mm

## Repeat the module (32 crystals) in an array 12x8
## (Create the complete detector --> 12x8=96 modules)
/gate/module/repeaters/insert cubicArray
/gate/module/cubicArray/setRepeatNumberX 1
/gate/module/cubicArray/setRepeatNumberY 12
/gate/module/cubicArray/setRepeatNumberZ 8
/gate/module/cubicArray/setRepeatVector 0. 9.2 18.4 mm

##### SYSTEM #####
# The system acts as an interpretor between the GATE geometry and data
# outputs for reconstruction, in our case, the ROOT/Interfile writer.
# A system must know which components of the geometry are parts of the
# scanner, and what their role are. For the moment, there is only a system:
# SPECThead; which was built when the SPECThead volume was inserted.

# The SPECThead system is made of three levels: base (for the head),
# crystal (for the crystal and crystal matrix) and pixel (for individual
# crystals for pixellated gamma camera)
# For now, only the base of the system is attached to a volume: the volume
SPECThead
# For the system to get information about your crystal and pixel, these
# levels (crystal and pixel) must be attached to their respective volumes.
/gate/systems/SPECThead/crystal/attach module
/gate/systems/SPECThead/pixel/attach pixel

# Look at the system
/gate/systems/SPECThead/describe

#### CRYSTAL SD ####
# The crystal SD makes it possible to record hits in a sensitive volume
# (e.g.,. in a scintillation crystal)
# It must be attached to any volume for which hit-data must be obtained
# For recording hits in the NaI volume only (the name of which is
# pixel) this volume is attached to the crystal SD.
# These command line must be inserted after the description of the
attachment
# to the system.
#/gate/crystal/attachCrystalSD  #Uncomment this line if you want to record
the hits in the crystal volume (In this case is made of Plastic)
/gate/pixel/attachCrystalSD

#####################################


All you have to do is:
- Change the dimensions and material of each volume;
- Configure the repeaters;
and good simulations :)  Notice that you can build your pixelated detector
without the "module" volume.


Best regards,

------------------------------------
Ricardo Capote

Institute of Biophysics and Biomedical Engineering
Faculty of Sciences, University of Lisbon
Campo Grande
1749-016 Lisbon

Tel. + 351 21 750 01 77; Fax: + 351 21 750 00 30
Extensão: 20510
Email: rmcapote at fc.ul.pt





> From: "Lee, Sam (SAM LEE)" <<mailto:slee91 at utk.edu>>
>
> Subject: [Gate-users] Pixelated detectors
> Date: February 3, 2012 8:58:29 PM GMT+00:00
> To: "gate-users at lists.opengatecollaboration.org<mailto:
> gate-users at lists.opengatecollaboration.org>" <
> gate-users at lists.opengatecollaboration.org<mailto:
> gate-users at lists.opengatecollaboration.org>>
>
> Hey all,
>
> I am trying to model a pix-elated detectors for my SPECT system.
>
> In Gate manual(In User Guide V6: Defining a system: SPECTHead), it says
> that I need to use "pixel" which can be used for modeling pixelated
> detectors. but it does not give any examples (as far as I know).
>
> What I do now is that I use cubic array to create an array of crystals and
> attach crystal-SD to it. I am not sure if this is the right way to do it.
>
> I was wondering if anyone can direct me to an example code containing
> pixelated detectors.
>
> Thanks,
>
> Sam Lee
>
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