[Gate-users] Source definition in STL complex geometry

[Josh Knowland]

Ashok,
I am not sure, but I believe "attach to" is used to move a source with geometry. By doing this, a small tight-fitting source can move around with geometry if it moves. Using confine to do this would mean that the source needs to be large enough to encompass the geometry as it moves without the source itself moving.

If you are moving geometry, I believe "attach to" is the right way to do it. If you are not moving, either should work. 

For lungs, I have created the lungs in STL and assign the Lung material. Obviously this isn't ideal because I don't currently leave space for air itself. Maybe I should do that. When placing the lungs inside the chest, I don't believe you have to carve our space. If you  make the lungs a daughter of the chest and confine a source to each, Gate will do the intersection for you. I think this is true, but you should probably test it.



-----Original Message-----
From: Ashok Tiwari <tiwarias at yahoo.com> 
Sent: Tuesday, January 15, 2019 12:32 PM
To: gate-users at lists.opengatecollaboration.org; Josh Knowland <jknowland at lucernodynamics.com>
Subject: Source definition in STL complex geometry

Hi Josh, 

I was also thinking in the similar way i.e, create a source that is slightly larger than STL file’s approximate size. 

Which command is best, confine or attach in source definition? I’m using attachTo instead of ../gps/confine  [volume].

Another thing: In my STL phantom, I’ve added lungs cavity and some spheres (lesions). I want to define a lung cavity so that it mimics the lung. In real phantoms styrofoam is added to mimic the lung. Any thoughts on this matter?

Thank you.

Ashok