[Gate-users] Moving Point source

[Sebastien JAN]

Hi Ahmet,

To try to reduce the computing time with the "confine source" option, we 
defined a loop counter in the GateGeneralParticleSource class.
When we have more than 100000 loops without an overlaping between the 
source and the source_volume, the event is killed.

2 solutions for you:

1/ you can change this limit in the code

2/ reduce the difference between the source and volume_source sizes 
(0.0001 mm against 25 cm.....). Recommended.

Cheers

Seb




ayanas at mail.med.upenn.edu wrote:
> Hello,
> I am trying to set-up a "moving Point source". 
> I thought I could simply do it by defining a very small sphere 
> embedded in a another sphere phantom and defining GPS as a sphere as in 
> the macro below.
> 
> However, when I decrease the radius of the "movsource" below 1 cm, 
> say, to 0.0001 mm to make the sphere source point like
> I get error messages " LoopCount = 100000
> Either the source distribution >> confinement
> or any confining volume may not overlap with
> the source distribution or any confining volumes .."
> 
> Could anyone comment on what I am doing wrong in the macro below? Or any 
> other suggestions or simpler methods for a moving Point source? 
> 
> thank you very much,
> 
> ahmet.
> 
> 
> ---------------------8<----------------
> # PHANTOM
> #
> /gate/world/daughters/name Phantom
> /gate/world/daughters/insert sphere
> /gate/Phantom/geometry/setRmin 0.  cm
> /gate/Phantom/geometry/setRmax 25.  cm
> /gate/Phantom/placement/setTranslation 0 25 0 cm
> /gate/Phantom/setMaterial Air
> /gate/Phantom/vis/setColor green
> #/gate/Phantom/vis/forceWireframe
> /gate/Phantom/attachPhantomSD
> /gate/Phantom/moves/insert translation
> /gate/Phantom/translation/setSpeed 0 0.004 0 cm/s
> /gate/Phantom/vis/setVisible 0
> 
> # A d d   a n  e x t r a   o b j e c t   f o r   s o u r c e   c o n f i n e m e n t
> /gate/Phantom/daughters/name movsource
> /gate/Phantom/daughters/insert sphere
> /gate/movsource/geometry/setRmin 0 cm
> /gate/movsource/geometry/setRmax 1 cm
> /gate/movsource/placement/setTranslation 0. 0. 0 cm
> /gate/movsource/setMaterial Air
> /gate/movsource/vis/setColor magenta
> #/gate/movsource/vis/forceWireframe
> /gate/movsource/attachPhantomSD
> 
> ### M o v i n g   S o u r c e   C o n f i n e m e n t 
> /gate/source/addSource SourceConfinement
> /gate/source/SourceConfinement/gps/type Volume
> /gate/source/SourceConfinement/gps/shape Sphere
> /gate/source/SourceConfinement/gps/radius 25 cm
> /gate/source/SourceConfinement/gps/centre 0 25 0 cm
> /gate/source/SourceConfinement/gps/particle gamma
> /gate/source/SourceConfinement/setActivity 10 Bq
> /gate/source/SourceConfinement/gps/energy 122. keV
> /gate/source/SourceConfinement/gps/confine movsource_P
> /gate/source/SourceConfinement/gps/angtype iso
> /gate/source/SourceConfinement/gps/mintheta 0 deg
> /gate/source/SourceConfinement/gps/maxtheta 180 deg
> /gate/source/SourceConfinement/gps/minphi 0 deg
> /gate/source/SourceConfinement/gps/maxphi 180 deg
> -----------------8<----------------------------------
>