Hi Fluka experts,
I am writing to talk about the unit of electron fluence scored by USRBIN, it seems that the unit should be particles/cm^3/primary instead of particles/cm^2/primary specified by the manual. Following are my considerations.
The electron beam is coming from the left, passing through the titanium window, the air and then into the water in the container. The water volume is a cylinder with 2.43 cm radius and 4 cm length.
Then I scored the electron in water region and the corresponding R-Phi-Z coordinate system with only 1 bin there, shown in the following two figures.
The simulation results are
3.6752E+00 and 4.9529E-02
respectively, the former is equal to the latter multiplying by the volume of water (~75ml).
If the former value is the total electrons per primary, then the unit of the latter one should be electrons per volume and per primary.
And there is a topic " The unit of energy deposition and fluence" mentioned that Fluka calculate the volume of the bin, I think that is similar to this situation.
If I set 2 bins along z direction, hold 1 bin along r direction. Then the results are
6.4229E-02 3.4828E-02
The total electrons per primary in the region can be calculated by
6.4229E-2 * 74.2/2+3.4828E-2 * 74.2/2 = 3.67,
which is around the result scored by the region.
Could you help check if this is a correct understanding? I am using this to score the 2D and 1D projection of electron fluence in the water region. Thanks.
Best,
Xi