Understanding geometrical efficiency

Scoring
1

pointsource.flair (1.7 KB)
pointsource.inp (1.1 KB)
Dear Experts,

I am trying to understand geometrical efficiency of a given detector geometry. In the file attached I am simulating a plastic scintillator of shape circular disk. I am using USRTRACK card in order to score fluence of particles passing through the detector volume.
The geometrical efficiency is defined as
=Number of particles falling on detector/ Number of particles emitted from source

I intend to integrate the fluence scored from USRTRACK card over all energies further multiplied by surface area of the detector. Since the fluence response is already per primary the value obtained should be geometrical efficiency.
Is my approach correct in order to obtain geometrical efficiency?

Thanks in advance.

3

Dear Mayank Singh,
in general Yes, but there is a detail in normalization factor.
I thin that the most comprehensive answer will be a quote from the user manual for USRTRACK card:

As scoring particle fluence with USRTRACK the resulting value will actually
be in cm -2 only if the user has provided the region volume (area) in the respective card field. Nevertheless, this is far from being needed, since the desired normalization can be naturally applied at post-processing level.

So yes, but keep in mind that output date is particle fluence, normalize to the region volume.

Kind regards,
Illia