From: Yung-Shun Yeh (adair.py94g@nctu.edu.tw)
Date: Tue Oct 09 2007 - 12:36:58 CEST
Dear Francessco,
Thanks for your kindly reply. I have a low level question. If I don't care
the waste of CPU time, can I set the DEFAULTS's SDUM to be PRECISSIO for all
simulations? Thank you very much.
Best regards,
Yung-Shun
On 10/8/07, Francesco Cerutti <Francesco.Cerutti@cern.ch> wrote:
>
>
> Dear Yung-Shun,
>
> I have in fact to clarify that the choice of NEUTRONS as DEFAULTS' SDUM
> is just intended to perform the transport of low energy neutrons (<19.6
> MeV) within the multigroup treatment. So, coming back to your questions,
> it is suitable ONLY for LOW energy neutrons. Since I saw that in your case
> you have also neutron beams with energies > 19.6 MeV, for them you need to
> perform nuclear interactions that indeed NEUTRONS neglect. Then, a
> proper choice is either SHIELDINg or NEW-DEFA (not explicitly requested,
> and good for MANY purposes). In the latter case, to avoid electromagnetic
> treatment, just put the EMF card with SDUM=EMF-OFF and, to save further
> time, put PAIRBREM with WHAT(1)=-3.0.
>
> Moreover, in your input the EVENTYPE and MUPHOTON cards are useless as
> well.
>
> Finally, to perform one million histories, it is better to split them into
> more cycles/runs (rfluka allows you to perform independent cycles in
> sequence), this way you will have also the possibility of getting
> statistical errors comparing the unformatted results of different cycles
> with the standard postprocessing tools (e.g. usxsuw for USRBDX).
>
> Thanks a lot to Alberto for pointing out these issues.
>
> Cheers
>
> Francesco
>
> **************************************************
> Francesco Cerutti
> CERN-AB
> CH-1211 Geneva 23
> Switzerland
> tel. ++41 22 7678962
> fax ++41 22 7668854
>
This archive was generated by hypermail 2.1.6 : Tue Oct 09 2007 - 13:06:32 CEST