Dear Vladimir,
Thank you for your query. I have checked your input, and unless I am mistaken in WHAT6 of the LOW-MAT cards you assign the same "tungsten" low-E neutron cross-sections to both your W182 and W183 materials, which may defeat the purpose of using a compound material for tungsten.
The problem is, there are no isotope-specific cross-sections in the list of FLUKA materials (see manual 1.4.1.2) for tungsten, but only for tungsten at different temperatures. This means that in terms of interactions with low-E neutrons you can only work with natural tungsten.
Alternatively, you could use Fluka to simulate the neutron spectra and then do an off-line folding of these spectra with external cross-sections of low-E neutrons for different isotopes, which you can find in a nuclear database. However, in this case you should be aware of the fact that the spectra provided by Fluka will be affected by the cross-sections which are already implemented in Fluka.
Yours,
Matteo
-----Original Message-----
From: owner-fluka-discuss_at_mi.infn.it <owner-fluka-discuss_at_mi.infn.it> On Behalf Of babintsev
Sent: 20 March 2019 10:47
To: fluka-discuss <fluka-discuss_at_fluka.org>
Subject: [fluka-discuss]: Re: Question about W neutron resonces
Hi, ALL,
I have checked different variants (and manuals also) about
neutron resonances, They absent in the output for
TUNGSTEN (W), And as I can see - for all other materials also.
May be somebody knows answers for the following questions :
1) I tryed to compose material from 182_W and 183_W isotopes,
but I think, that something is wrong...
Could you please check my test.inp - file in the atachment ?
2) does anybody know the simple method to simulate some
known resonances for the given material ?
(where are there data with cross-section vs E ?)
3) is there open and free method to fit (reconstruct)
this simulated or real resonances ?
thanks,
Vladimir Babintsev
16.03.2019 8:57, babintsev пишет:
> Dear experts,
>
> I want to check neutron resonances like ex-5 with Cd foil.
> For this I use lead target in moderator (polyethylene)
> then I look at N flux using the hole in the concrete wall.
> I use W foil and NEW-DEFA
>
> In the attachment there is the picture of N flux into
> W-foil and output from the foil.
> There is NO ANY resonance here.
>
>
> So, my questions :
>
> - I use TUNGSTEN here, it is known that natural W consists from
> 4-5 stable isotopes, which have neutron resonancies
> TUNGSTEN in FLUKA is natural ? 4 isotopes ?
>
> - if TUNGSTEN is not natural - then how I can create this material ?
> I cannot find any example, how to compose materials from isotopes -
> because I need names , which I do not know
>
> could you please give me this example ?
>
> - what else I must do to see the picture as I see for Cd in ex-5
> with neutron resonance ?
>
>
> thank you
> Vladimir Babintsev
>
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Received on Thu Mar 21 2019 - 18:00:14 CET