Dear Tsviki,
If you would like advice on your specific problem please post the input,
any user routine, as well as the used cross section data.
Thus, I can only make the following, more general comments:
- It would be more appropriate to score fluence with USRTRACK inside the
region in which you score with RESNUCLE. Depending on the tickness of
your target, the incident fluence gets attenuated, the spectral shape
changes and secondaries are produced which may create also nuclides.
- Use exactly the same cross sections as used in or predicted by FLUKA if
you aim for identical results.
- If fluence from USRTRACK is folded offline with the same cross sections
as used in or predicted by FLUKA, and assuming that nuclide production
is approximately homogeneous in the target volume, you will get the same
numbers as with RESNUCLE. This has been done before several times.
- Assuming normal incidence on the boundary, fluence and currect scoring
must give the same spectrum. I can only tell you more why it doesn't in
your case if I see the input.
Best regards
Stefan
On Thu, 7 Jan 2010, Tsviki Hirsh wrote:
> Dear list,
>
> We have simulated a production of an isotope from ISOLDE fast spallation
> neutron source.
> The activation was calculated using three methods,
> 1) Getting the neutron fluence spectrum with USRDBX and then integrate
> with the cross section.
> 2) Getting the neutron current spectrum with USRDBX and then integrate
> with the cross section.
> 3) Doing the "full simulation" using RESNUCLE.
>
> The target is a simple cylinder positioned inside the neutron flux.
>
> The problem is that we are getting different results using each one of the
> methods, even though we have used an identical cross section in the calculations.
> The production numbers were (all scaled down):
> 1) 4.8 using fluence
> 2) 2.4 using current
> 3) 2.8 from RESNUCLEI
>
> Which of the above is the correct? What is the reason for the differences?
>
> Thank you,
> Best Regards,
> Tsviki Hirsh
> Weizmann Ins. of Science, Israel
>
>
>
>
-- ___________________________________ Stefan Roesler CERN, DGS-RP CH-1211 Geneva 23 Switzerland Phone: +41-22-7679891 Fax: +41-22-7669639 E-mail: Stefan.Roesler_at_cern.chReceived on Thu Jan 07 2010 - 22:07:54 CET
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