# EVENTBIN with optiphot count

Dear experts,
I want to know how the mass ratio of 6LiF/ZnS:Ag impact the number of generated optical photon(just generated, not after transported), my work is below:
1、Calculate the thickness required to deposit full energy at each mass ratio；
2、Select the maximum thickness value and calculate the sum of photons counted by EVENTBIN at each mass ratio.
What I understand is that at this maximum thickness, the energy generated at all mass ratios will be fully deposited. So the best mass ratio can be determined by changing the mass ratio and observing when to get the maximum number of photons produced.
In theory, the larger 6LiF, the more photon number, but actually is opposite.
My question is if EVENTBIN card is not suitable at here or I am use it wrong?
I just want to know the number of photons that were generated initially, not the number of photons that have been transmitted and attenuated.
The attachment is my file and hopefully get your help.mixture.flair (3.3 KB)

This maybe not a software question, I request withdraw it

Dear @xiongbp,

The production of optical photons is controlled by the user by means of the OPT-PROD card. In particular, WHAT(2) of the card for SDUM = SCINT-WV controls the fraction of deposited energy going into scintillation photon emission. Therefore, the production of photons in your material as simulated by FLUKA will only be influenced by the mass ratio of its components as a consequence of the possible variation in the deposited energy in the region containing 6LiF/ZnS:Ag. As your OPT-PROD card is defined, 13.2 % of the deposited energy will be invested in the emission of photons of 4.5\cdot10^{-5} cm wavelength. If you increase its dimensions you may generate more photons, but just as a consequence of depositing more energy.

Regarding the scoring, if you would be interested in the number of photons exiting your 6LiF/ZnS:Ag, then probably the best option is to score current by means of a USRBDX scoring.
I am not sure why are you interested in using EVENTBIN, which gives you information after each event. In case you would like to see the spatial distribution of your photons then you could use USRBIN instead.

If you still want to know the number of photons generated, today is your lucky day : it is printed for free in the standard FLUKA output (you can search for “optical photons”). But note that it is the addition of all events in the cycle, to get it per primary neutron you need to divide by the number of primaries used in the cycle of interest.

Hope it helps.

Kind regards,
Francisco

Dear @fogallar
At last, what is your say “the addition of all events in the cycle”, which card to achieve it?

Dear @xiongbp,

If you choose to simulate X primary particles (neutrons) per cycle and you get a total of Y photons (in the .out file), then the number of photons per primary particle would be Y/X. You do not need any card.

Kind regards,
Francisco

Dear @fogallar
That’s OK, thank you!