Hi. Tell please is there in fluka card for obtaining the nuclear reaction channel ? For example I irradiate oxygen by gamma quanta and want to know how much times there realised the next reactions:
gamma+16O → 7Be + 9Be and gamma+16O → 7Be + 2alfa + neutron. Is it possible in fluka ?
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Yes, it is. You should irradiate your oxygen target with a photon beam, activate photonuclear interactions with PHOTONUC, bias them with LAM-BIAS to increase their statistics, and for instance setup a customized event-by-event scoring by means of the mgdraw user routine, to be activated by USERDUMP. For your convenience, I attach an input file
photonuc.inp
where I selected a 16O solid target (to further increase the photon reaction probability, in addition to the artificial LAM-BIAS factor)
and a suitable mgdraw version
mgdraw.f
printing any photon reaction outcome on the unit 72 (photonuc001_fort.72).
Please look at the manual and use the Compile tab of Flair to build an executable embedding the customized mgdraw.
The channels you refer to will appear as:
new reaction at 35.000000000000000 MeV
generating 0 particles of ID
and 2 fragments with A = 7 9
and Z = 4 4
respectively
and a residue with A = 0 and Z = 0
(7Be+9Be) and
new reaction at 35.000000000000000 MeV
generating 1 particles of ID 8
and 2 fragments with A = 4 4
and Z = 2 2
respectively
and a residue with A = 7 and Z = 4
(7Be+alpha+alpha+n).
Since this is an event-by-event scoring, it’s up to you to deduce the channel probability by counting the respective instances and the total number of reactions at the considered photon energy.
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I can’t find Colmpile tab. Can you tell where is it located ?
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I did everything as you said, but after run there is no produced any file of _fort.72.
Dear @s.amirkhanyan ,
please make sure you are using the compiled executable. See slide 23:
If you are using your own input file, did you add an the USERDUMP card to your input, as it is required to activate the mgdraw.f user routine? The the example input file in the post above.
If you did, then please upload your input.
Cheers,
David
No, I’m using input that you uploaded here.The problem was that there was not set the value of unit equal to 72 in USRDUMP card. I set it to 72 and problem solved. But now I have the next question. Why there in _fort.72 files somewhere after ID there are nothing written and somewhere are written some number ? For example.
new reaction at 35.000000000000000 MeV
generating 0 particles of ID
and 1 fragments with A = 3
and Z = 2
respectively
and a residue with A = 13 and Z = 6
and
new reaction at 35.000000000000000 MeV
generating 1 particles of ID 7
and 1 fragments with A = 2
and Z = 1
respectively
and a residue with A = 14 and Z = 7
I can hardly believe this: for the mgdraw version I provided, the unit number input in the USERDUMP card should be irrelevant (72 is hard coded in the user routine) and indeed I did not need it. Thanks for checking again carefully and confirming your findings.
Nothing is written if you get 0 particles, one FLUKA particle ID is written if you get 1 particle, two IDs are written if you get 2 particles, etc. (see below for the definition of ‘particles’).
The reaction products are categorized by FLUKA in the three printed groups: particles with FLUKA ID normally larger than 0, heavy fragments from deuterons onward, and one heavy residue (unless emitted particles and heavy fragments already exhaust the product list).