# Energy of electrons on the target

Dear experts,
I have two simple questions.
I want to explain the energy of electrons on the target when a proton beam interaction with the Al target.
in the real experiment, I have 10^10 protons in the initial proton beam with 1mrad distribution.
So if I defined 10^6 primary particles with 1mrad distribution is it ok?
In the final step, how can report the result? Should I multiple my results to 10^10(number of protons in the initial proton beam)? and in the other hand what is the unit of energy in the 2D plot? is it GeV/cm^3/unit primary weight or GeV/cm^3?

but I need more clearly about it.
thanks so much.

Assuming you are using the USRBIN scorer, the values that are reported are indeed in GeV/cm^3 per primary particle. This is accurate if you did not use biasing, otherwise it is more general to say that results are reported per primary weight.

From the FLUKA manual Section 7.16 USRBIN note 5):

``````     5) Energy deposition will be expressed in GeV per cm3 per unit primary weight. Doses will be expressed in GeV/g per unit primary weight. To obtain dose in Gy, multiply GeV/g by 1.602176462E-7
``````

If you wish to obtain the energy deposition for a particular beam, it would be appropriate, like you suggest, to scale the results by the known number of primaries of that beam.

Deae @blefebvre ,
Thanks.
I used USRBIN and my primary particle is 10^6 protons.
But I like to report my result (electron energy deposition not proton energy) in GeV/cm^3 for a Proton beam with 10^10 protons interact by Al foil.
So is it correct I multiple electron energy to 10^10? Is it correct(primary particle = 10^6 protons)?

actually, I am a little confused about how can handle the relation of the number of simulated primary protons with the energy of the electrons produced. And convert it to a real value for comparison with experimental data
thanks
Best regards,

Using the AUXSCORE card it is possible to filter the particle type of a detector created using USRBIN.

I do not recommend filtering electrons with FLUKA because of the production cut-offs. Electrons below a predefined energy threshold are not tracked by FLUKA. If below threshold, the energy deposition of a particle is accounted in the energy deposition of the parent particle. The parent particle is almost always of a different type for EM processes.

I recommend instead that you score the electromagnetic energy deposition using the option EM-ENRGY. This option, which combines electrons, position and gamma particles, should provide more meaningful results.

In any case the results from USRBIN are reported per simulated primary particle. If you score electrons and you simulated protons, the results are expressed per primary proton, not secondary electron.

Dear @rezaei.m.p,

Fluka energy deposition results are always given in GeV/cm^3 per primary particles. It doesn’t matter how many primaries have been simulated, it could be 10 primaries or 10^6 or 10^100, results will always be per primary particles. The number of primaries makes instead a difference on the statistical uncertainty of the results, obviously a large number of primaries will give results with smaller uncertainties.

If you want to provide your results, let’s say, per bunch and a bunch is made of 10^6 primaries, than you just need to apply a 10^6 normalization.

It is a bit less clear to me what you mean with “electron energy deposition not proton energy”. It is always difficult, if not meaningless, to define the energy deposited by a primary versus that deposited by the secondaries generated, as this are indeed generated by the primaries (either directly or in a shower). Therefore, I advice to be careful if you want to follow on such approach.