[gate-users] cylindricalPET

[Yun Dong]

Hi Fernando,

Thanks for your reply. I give my some configures of simulation here:

Geometry: ~250mm*175mm dual-panel, distance between them is 50mm
# P H Y S I C S
/gate/physics/gamma/selectCompton standard
/gate/physics/gamma/selectPhotoelectric standard
/gate/physics/gamma/selectRayleigh lowenergy
/gate/physics/setElectronCut 300. cm
/gate/physics/setXRayCut 1. GeV
/gate/physics/setDeltaRayCut 1. GeV
# D I G I T I Z E R
/gate/digitizer/Singles/insert adder
/gate/digitizer/Singles/insert readout
/gate/digitizer/Singles/readout/setDepth 1
/gate/digitizer/Singles/insert blurring
/gate/digitizer/Singles/blurring/setResolution 0.15
/gate/digitizer/Singles/blurring/setEnergyOfReference 511. keV
/gate/digitizer/Singles/insert thresholder
/gate/digitizer/Singles/thresholder/setThreshold 250. keV
/gate/digitizer/Singles/insert upholder
/gate/digitizer/Singles/upholder/setUphold 750. keV
/gate/digitizer/Coincidences/setWindow 100. ns
# S O U R C E S
/gate/source/addSource twogamma
/gate/source/twogamma/setActivity 1000000. becquerel
/gate/source/twogamma/setType backtoback
/gate/source/twogamma/gps/particle gamma
/gate/source/twogamma/gps/energytype Mono
/gate/source/twogamma/gps/monoenergy 0.511 MeV
/gate/source/twogamma/gps/centre 0 0 0 mm
/gate/source/twogamma/gps/type Volume
/gate/source/twogamma/gps/shape Sphere
/gate/source/twogamma/gps/radius 0.5 mm
/gate/source/twogamma/gps/confine NULL
/gate/source/twogamma/gps/angtype iso
/gate/source/twogamma/gps/mintheta 0. deg
/gate/source/twogamma/gps/maxtheta 180. deg
/gate/source/twogamma/gps/minphi 0. deg
/gate/source/twogamma/gps/maxphi 360. deg

Just now I made some tests with resetting configure in "benchmarkPET"
coming with GATE package: 
1. (camera.mac 127L) /gate/head/ring/setRepeatNumber 4 (I also try 2)
2. (benchmarkPET.mac 45L)/gate/output/ascii/setOutFileCoincidencesFlag 1
(enable ascii coincindences output).
Then I find that when two heads, the size of coincindence ascii output
file is always zero after simulation start. But when 4 heads, the size
increases during the simulation. That's so confusing. 

Thank you again.

Best Regards
Yun



----- Original Message -----
From: Fernando Rannou <rannou at diinf.usach.cl>
Date: Monday, July 18, 2005 11:28 am
Subject: Re: [gate-users] cylindricalPET

> Hi Yun
> you should get coincidences. Among the questions I would ask are:
> 1) What kind of output are you using? I assume you set the digitizer
> appropriately to collect coincidences.
> 2) how much activity, for how long?
> 3) are you simulating a positron emitter (of course)?
> 4) How big are the detectors with respect to the FOV?
> 
> Fernando
> 
> 
> 
> On Mon, 2005-07-18 at 12:10 -0500, Yun Dong wrote:
> > Hi everyone,
> > I am just simulating two parallel-panels PET system through
> > cylindricalPET system in GATE. Howver, I never get coincidences, 
> just> GateSingles. Does it mean that cylindricalPET can never 
> simulate the
> > open two parallel-detector PET system? Dose anybody have some idesa?
> > Thank you so much.
> > 
> > Best Regards
> > Yun
> > _______________________________________________
> > gate-users mailing list
> > gate-users at lphe1pet1.epfl.ch
> > http://lphe1pet1.epfl.ch/mailman/listinfo/gate-users
> 
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