FLUKA: Cross section output

[Alberto Fasso' <fasso@slac.stanford.edu>]

On Fri, 12 Jan 2001, Laurent APHECETCHE wrote:

> I'm using the RESNUCLEi card with WHAT(1)=3, to have all residual nuclei
> produced (in a Pb-Bi target). I use WHAT(4)>0 in the LOW-NEUT card to
> have some printout of the available xsec, but I'm not so sure I cleary
> understand this output. Could you explain me what are all the columns :
>
> 1                     CROSS SECTIONS FOR MEDIA    23
>                       (RESIDUAL NUCLEI INFORMATIONS AVAILABLE)
>  GROUP    SIGT    SIGST   PNUP   PNABS  GAMGEN NU*FIS   EDEP    PNEL
> PXN    PFISS PNGAM
>       barn      barn
>
> ?

Hi,
I was hoping that somebody else more knowledgeable would answer,
but since there has been no answer so far, this is the meaning as
far as I know.

   Alberto

======================================================================
>  (RESIDUAL NUCLEI INFORMATIONS AVAILABLE)

This line is self-explaining: for this material it is possible to get
residual nuclei scoring also from low-energy neutron reactions
(if you set WHAT(1) = 2.0 or 3.0 in option RESNUCLE). If the line is
not there for a certain material, only spallation/evaporation residual
nuclei can be scored.

>  GROUP
Energy group number

>  SIGT
Total cross section

> SIGST
Scattering cross section

> PNUP
Probability of upscatter (can be different from zero only if there are
several thermal groups, which is not the case with the present FLUKA
cross sections)

> PNABS
Probability of Non-ABSorption (= scattering). It is = SIGST/SIGT, and
can sometimes be > 1 because of (n,xn) reactions

> GAMGEN
GAMma GENeration probability = gamma production cross section divided by
SIGT and multiplied by the average number of gammas per (n,gamma) reaction

> NU*FIS
fission neutron production = fission cross section divided by SIGT and
multiplied by nu, the average number of neutrons per fission

> EDEP
Kerma contribution

> PNEL, PXN, PFISS, PNGAM = partial cross sections, expressed as
probabilities (i.e. ratios to SIGT). In the order:
    non-elastic, (n,xn), fission, (n,gamma)


-- 
Alberto Fasso'
Stanford Linear Accelerator Center
Radiation Physics Dept. ms 48, 2575 Sand Hill Road, Menlo Park, CA 94025
Tel. +1 650 926 4062        Fax: +1 650 926 3569
fasso@slac.stanford.edu     Alberto.Fasso@cern.ch