Re: Problem with MATERIAL card

Dear Angelo,

> Yes, you are right. This is a second input that i have made and i have
> called AIR->ARIA, but the real problem is not the name that i gave it but
> the fact that this name not appear in the compound e assigmat cards
> (this is
> the motivation because you don't see the name ARIA in the compund card)..
>
>

Let me try to clear things a bit up (please correct me if I am wrong!).
Whenever you are trying to define a MATERIAL (using the MATERIAL card)
you have either to define it with a name that already exists in the
fluka low-neutron library (you can see the library materials here:
http://www.fluka.org/fluka.php?id=man_onl&sub=97 ) , or to bound it with
the low-neutron library using a "low-mat" card. If you don't do so,
FLUKA doesn't know what to do with the low-energy neutrons, that's why
the code returns an error. In your case, since you are defining an
Isotope of Nickel, if you want to connect it with the cross section of
the Natural Nickel, you should either name it "NICKEL" (and fluka
automatically connects it with "Ni Natural Nickel 296K ENDF/B-VIR8 Y
NICKEL 28 -2 296 Y", because it is the first on the list) or name it
"MYNICKEL" and bind it with "Ni Natural Nickel 296K ENDF/B-VIR8 Y NICKEL
28 -2 296 Y" using a "low-mat" card (and the flair drop-down menu, if
you are using flair)

As for the case of AIR, as I can understand your case, you want to
define the COMPOUND "AIR" by percentages of 0.21 Oxygen and 0.79
Nitrogen. In order to do that, you firstly have to define a MATERIAL
card in which you will fill in only WHAT(3) (density) and WHAT(7) (Name,
which is "AIR" in your case) and, afterwards, define a COMPOUND card,
in which you will put the SDUM (or the "Name" in flair) AIR, and
afterwards define the percentages of the material (as correctly you have
done in your input).

> I gave the name Ni to my defined Nickel for not have the problem of a
> name
> too long. I don't belive that is this the problem, but i will try
> with"MYNICKEL or somethings like that.
> Sometimes i have this problem when i define a compund: for example i
> usually
> use a compound with Co, Cr and Ni. I define Co and Cr with material cards
> and after i define the compund.
> If i don't active the LOW-MAT card for the Cr, FLUKA give me the
> message of
> NO RANDOM FILE error.... but i don't understand why!

The reason is, as far as I understand it, that FLUKA doesn't know what
to do with the low energy neutrons, since you have defined a material of
your own composition, and a name of your choice. It searches for the
name in the low-energy library, cannot find it, and, unless you have
defined a low-mat card which "tells the program what to do" with your
material, it crashes.

I hope that this helps you a bit,
All the best,
N. Charitonides
Received on Sun Nov 15 2009 - 23:39:19 CET