|Message: Re: Simulating and calculating Geometric Factors in GEANT4||Not Logged In (login)|
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thank you for you answer. I found out that original expressions was indeed wrong, but the one I found after is also different from yours.
The expressions I found for the Geometric Factor G, is:
G = (Nc/Ne) * 4 * Pi^2 * R^2
where: Nc = Number of captured particles Ne = N. emitted particles R =Source radius
I came to this by using a paper from Sullivan, 1971.
The Counting rate C is related to the Isotropic source intensity (I0) by: C = G * I0
Excluding any time dependency, the Intensity becomes the number of emitted, and captured particles.
If I define a source sphere where the particles are only emitted inwards, then the solid angle, O, comprised by those particles is: O = Pi
and the source intensity becomes: I0 = Ne / (S * O) = Ne / (4 * Pi^2 * R^2)
where: S = Surface area
and using the definition of G from Sullivan, I arrive at the GF I've given before.
All the best, Bruno
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