RE: [fluka-discuss]: Uranium with LOW-MAT for neutrons & HEAVYIONS

From: <>
Date: Tue, 17 Jun 2014 01:05:47 +0200

Dear Vasilis (& Fluka users),

Haha! I like to do questions in batches :) Thanks for the answers!
Much appreciated!

Just to clear things up (I'm a bit confused):

I am now comparing the plots with the _tab.lis and _sum.lis files.

For the USRYIELD the _sum.lis file just says the units are double
differential, so I assume it's per charge&energy since my two
variables are particle charge and kinetic energy. The quantity in the
files are identical to what is in the plots. Is it it just giving me
the number of particles produced in the energy range and within the
bin per primary particle or do I have to multiply by something? I get
e.g. 3E-7 from particle charge 44.5 to 45.5.

For the USRBDX the units seem to be particles per GeV, cm^3 and
primary. E.g. 9.8E-4 GeV^-1 cm^-3 primary^-1 from 0.030-0.031 GeV. Do
I then multiply by 0.001 (bin width) to get the fluence in that
specific energy range?

But what is meant by cm^3? It's just a boundary...

And again with the uranium. Does this look ok?:

MATERIAL 92. 235. 18.95 U235
MATERIAL 92. 238. 18.95 U238
COMPOUND -0.9928 U238 -0.0072 U235 URANIUM
LOW-MAT U238 92. 238. 296. 238-U
LOW-MAT U235 92. 235. 296. 235-U

Input file is attached.

Best regards,
Vegard Gjerde

Quoting Vasilis Vlachoudis <>:

> Dear Vegard,
> you have exceeded your weekly quota for questions :)
> 1. RESNUCLEI: Spalation the manual is self-explanatory. I cannot
> write anything more
> 2. Low Energy neutrons are treated separately with the multi-group
> approach. It will include
> all residual produced by neutron interactions including fission products.
> 3. "All" correct
> 4. Number of stopping particles = fall below the threshold
> 5. From the USRYIELD if you have biasing you cannot get back counts.
> If you multiply with
> the bin widths you will get the sum of the entries within the bin.
> 6. Emerging is after an interaction, while region to region is on
> boundary crossing
> 7. The output in the _sum.lis and the _tab.lis is self explanatory.
> Open the files with a text
> editor and you will see the units.
> Please forget the manual for this point, since it refers to the
> unformatted (binary) files produced
> by FLUKA. All ascii files used for plotting is already
> normalized and have fluence/energy per primary
> and ONLY if you plot the double-differential then you get
> fluence/energy/solid angle per primary
> 8. There is no natural Uranium in the FLUKA database. You have to
> make a compound with the
> correct 235,238U composition. No need for LOW-MAT cards if you
> call the materials with the same
> name as in the database
> 9. Z are included. The particle HEAVYION has always the number 2,
> but then to decode it you need
> to create a user routine. OR for scoring purposes you can use a
> filter with the AUXSCORE card
> Cheers
> Vasilis
> ________________________________________
> From:
> [] on behalf of
> []
> Sent: 15 June 2014 18:19
> To:
> Subject: [fluka-discuss]: Uranium with LOW-MAT for neutrons & HEAVYIONS
> Dear Fluka users,
> I'm wondering about the material URANIUM from the database. Is it
> natural uranium, which contains ~0.7% 235 and ~99.3% 238? I've added
> two LOW-MAT cards, one for 235U and one for 238U. Will this be correct?
> I'm also wondering about what atomic numbers Z are included in
> HEAVYION. Where does it start?
> Best regards,
> Vegard Gjerde

Received on Tue Jun 17 2014 - 02:16:00 CEST

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