[Gate-users] Moving Point source

[ayanas at mail.med.upenn.edu]

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<----------------------------------

-- 
Ahmet Sedat Ayan, Ph.D

Department of Radiology
University of Pennsylvania
Philadelphia, PA 19104

Voice      : (++ 1 215) 349-5751 (W) (GMT-5)