Re: [fluka-discuss]: Neutron induced fission in 238u

From: <me_at_marychin.org>
Date: Fri, 23 May 2014 23:03:58 -0700 (PDT)

(I'm resending this to the original thread, just for better fluka-discuss
book-keeping, as Alberto's reply went into the wrong thread.)

> On 23 May 2014 at 02:26 Alberto Fasso' <fasso_at_slac.stanford.edu> wrote:
>
>
> Dear Francesca,
>
> first of all, in your input some material names (238UOx, BUTYL) are not
> aligned
> on column 71, and the program certainly assumes that their name begins with
> one
> or two blanks. Thus, the LAM-BIAS command fails to associate the name you give
> with that of a material assigned to a region.
>
> In addition, when using LAM-BIAS to bias the inelastic interaction length, you
> have only a choice between one material or all materials. You cannot ask for
> two materials. You have issued two LAM-BIAS cards: the first is associated
> with
> 238-U, which is not assigned to any region, although it is used to define the
> compound 238UOx. Then you have issued a second LAM-BIAS card for 238UOx, which
> I guess must be ignored, since you have already requested one (useless) for
> 238-U.
>
> Summarizing:
> - adjust the alignment in the MATERIAL definition of 238-U and BUTYL
> - remove the LAMB-BIAS card for 238-U and leave only that for 238UOx.
>
> I would like to add a little piece of advice on a different issue. Calling all
> bodies B53, B72, etc., and all the regions A017, A023 etc., is not a very
> smart thing.
> It is not wrong, of course, but it does not take advantage of the huge effort
> which has been made by the FLUKA developers to allow the users to use mnemonic
> names. In your case (118 bodies and 104 regions) it is really hard to remember
> what is what (I tried to identify the 238UOx region, and I gave up). In
> addition, if you want to add or remove one body, you either re-number all of
> them,
> or get even more confused. I admit that this was the way we all worked in a
> far
> past, before the names were introduced: but now we can avoid it, especially if
> there is a large number of bodies and regions.
>
> Alberto
>
> On 22 May 2014 at 02:32 "francesca.belloni_at_libero.it"
> <francesca.belloni_at_libero.it> wrote:
>
>
> Dear all,
> I am trying to score fissions in (8-U)oxyde, to "confirm" results by
> another code.
> But when I run the FLUKA simulation for this problem, the result of
> SCORE FISSIONS HE-FISS LE-FISS
> is 0.0 0.0 0.0 respectively.
>
> The incident neutrons have a kinetic energy of 1 MeV and are
> isotropically emitted.
> The 238U oxyde layers are really thin, therefore I added 2 LAM-BIAS cards (one
> for 8-U and one
> for (8-U)oxyde. By the way...is it fine putting a LAM-BIAS in both materials
> or by using only
> a LAM-BIAS card associated to U8 would have been enough, please?)
>
> Did I forget something, please?
>
>
> Thank you and best regards,
> Francesca
Received on Sat May 24 2014 - 09:08:11 CEST