[Gate-users] Back to Back source

[Alexandre Dupas]

Dear Emmanuel,

Since, I don't really know what bugs are corrected by the
BackToBack.cc you use, I would suggest to try setting the
accolinearity to 0 deg and accolinearity flag to false using the
following commands:

/gate/source/twogamma/setAccolinearityFlag false
/gate/source/twogamma/setAccoValue 0 deg

and looking if the result still contains some accolinear photon pairs.
As I said previously, using Gate v5 (with some patches), we don't have
such issues anymore but I cannot say about Gate v6.

Best regards,
Alexandre
--
Alexandre Dupas
Postdoctoral Research Fellow
INSERM U698, CHU X. Bichat, Médecine Nucléaire

2011/2/21 Emmanuel BRARD <emmanuel.brard at iphc.cnrs.fr>:
> Dear Gate users,
>
>
>
> I am still under investigation for my positron issue in the meantime though
> I have decided to try with a back to back source. I downloaded the file
> BackToBack.cc which has been sent over the maillist since the one
> distributed with 6.0.p01 does not work. The emission seemed correct to me,
> at least the random behavior disappeared but I noticed a strange behavior
> with co-linearity. I would  like to have a perfect back to back emission
> with no acolinearity at all which seems to be the default value according to
> file ./physics/src/GateVSource.cc:66:  m_accolinearityFlag = false;
>
> But I still have some non-colinear emission so I tried to force It with the
> Gate command /gate/source/twogamma/setAccolinearityFlag true but this issue
> would not disappear.
>
>
>
> Hereafter is a copy of my source file :
>
> # Back to back source for F18 (from manual)
>
>
>
> /gate/source/addSource twogamma
>
>
>
> /gate/source/twogamma/setActivity 100000. becquerel
>
> /gate/source/twogamma/setType backtoback
>
> /gate/source/twogamma/gps/particle gamma
>
> /gate/source/twogamma/gps/monoenergy 511. keV
>
> #/gate/source/twogamma/setForcedUnstableFlag true
>
> #/gate/source/twogamma/setForcedHalfLife 6586 s
>
>
>
> /gate/source/twogamma/gps/type Plane
>
> /gate/source/twogamma/gps/shape Circle
>
> /gate/source/twogamma/gps/radius 15.0 mm
>
> #/gate/source/twogamma/gps/type Point
>
> #/gate/source/twogamma/gps/centre 0.8 0.8 0. mm
>
>
>
> /gate/source/twogamma/gps/angtype iso
>
> # Uncomment the parameters below if you want the source
>
> # to emit in an XY (transverse) plane
>
> /gate/source/twogamma/gps/mintheta 90. deg
>
> /gate/source/twogamma/gps/maxtheta 90. deg
>
> # The parameters below mean that the source emits
>
> # at all angles in the transverse (XY) directions
>
> /gate/source/twogamma/gps/minphi 0. deg
>
> /gate/source/twogamma/gps/maxphi 360. deg
>
>
>
> #/gate/source/twogamma/gps/minphi 90. deg
>
> #/gate/source/twogamma/gps/maxphi 90. deg
>
>
>
> /gate/source/twogamma/setAccolinearityFlag true
>
>
>
> Thank you,
>
> Best regards,
>
>
>
> --
>
> BRARD Emmanuel
>
> emmanuel.brard at alumni.u-psud.fr
>
> Medical Physics - PhD Student
>
> IPHC IMABIO Bat 25 - 23 rue du Loess
>
> 67037 Strasbourg Cedex 2
>
> FRANCE
>
>
>
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