[gate-users] spblurring folow-up

[Christian Wietholt]

Dear all,

I know I have been posting a lot about the spblurring functionality in Gate, 
and I apologize for any unnecessary posts. As I mentioned in a previous post, 
the blurring does not have any effect on the globalPosZ variable in 
gateSingles.dat file. But, when I want to create an image from the ASCII 
output for a 0 degree projection, don't I use globalPosZ as the value for the 
ordinate, and the globalPosY as the value for the abscissa in the projection 
image. Please correct me if I am wrong. If spblurring does not have any 
effect on globalPosZ, how can I create a representative projection image?

In my simulation I simulated a pointsource projecting through a 5mm pinhole 
which should result in a projected disc of 10mm radius. I did spblurring of 
0mm and 30mm (30mm is just for demonstrating the effect). 
Below please find the distribution values of globalPosX, Y, and Z in 
gateSingles.dat. Btw. I get similar results in Gate 1 & 2.

for a 0 degree simulation: Here I think x is just the depth of the Single in 
the detector and does not play a role in the image formation, but Y and Z 
should be the image coordinates.

spblurring 0mm:
	average	var		stdev
X	242.491	3.228	1.797
Y	0.528	70.873	8.419
Z	0.140	91.875	9.585

spblurring 30mm:
	average	var		stdev
X	241.315	176.202	13.274
Y	1.332	258.672	16.083
Z	0.140	91.875	9.585     

(for Z I think the stdev should be similar to the stdev of Y)

I would appreciate any comments or corrections to this line of thoughts. 
I am looking forward to hearing from you. 

Best Regards, 

Christian