Re: SCORE estimator

From: Alberto Fasso' <fasso_at_SLAC.Stanford.EDU>
Date: Sun, 14 Aug 2011 14:28:32 -0700 (PDT)

Dear Mina,

it is a good idea that of using the SCORE command for quick debugging/testing.
But I am afraid you haven't got the right information about it, as you can
read on the manual

> I have just found that if I define more than one SCORE estimator cards,
> only the first one will have information in the output file. There is no
> warning or error messages saying I can only have one SCORE card defined. Is
> this the intended behaviour?

What you say is not correct. The SCORE command can only allow to score a
maximum of 4 distributions. If you define 2 distributions in one card, you
can still issue another SCORE card with two more distributions (or two more
cards with one distributions each). All these cards are taken into account,
not only the first one. But if you request 4 distributions with one card,
all following SCORE cards are ignored, because the maximum has been reached.
Note also that if you request 2 distributions with one card, and 4 more with
another card, those you will see in output will be the first two, plus the
first two on the second card. The third and fourth on the second card will
be ignored.
There is no warning or error messages, because there is no error: just a
redundant card. All your requests have been satisfied.

> Also, if I use BEAMPART as one of the score quantities, do I get the
> beam particle density in a region, normalized by the volume of the region or
> stars generated by the beam particle?
> I am asking since the title in the output says "Beampart Star Denstiy
> (STAR /cm^3 /one beam particle)

You don't get "the beam particle density", but the "beam particle STAR density",
as is clear from the title. The volume of the region is known to the code
only if you have set = 3 the first variable in the Geometry title card
(called IVOPT so far: Integer VOlume OPTion, although the name will be probably
changed in the next version). And then, you must type one volume value for
each region just before the GEOEND card, as explained in the following text,
copied from the manual:
"an optional set of cards which must be input if (and only if) flag IVOPT in the
CG Title card has been given a value 3. As many volume definition cards must be
given as is needed to input a volume for every region. The input variable is an
array VNOR(I) = volume of the Ith region. The format is (7E10.5). Volume data
are used by FLUKA only to normalise energy or star densities in regions
requested by the SCORE command".
If you don't do this, each volume is assumed to be 1.0 cm3. The volumes are
output in the second column of the SCORE output.
Therefore, the unit "STAR /cm^3 /one beam particle" must be intended as
STAR /one beam particle) in case volumes have not been provided. The cm3
in the title are those output in the second column: 1 cm3 if volumes have
not been input.

> I am using the SCORE card for quick debugging/testing purposes since I
> am not getting any interactions from a 25 MeV proton beam incident on
> Be-Ta-Al-VacGap-dUCX3 where Be: Beryllium, Ta: Tantalum, VacGap: Vacuum Gap,
> and duC3Gr: depleted Uranium Carbide/Gr mixture compound,
> in any regions defined by the above material.

At 25 MeV, the cross section for producing stars is very low, and it can well
be that most of your beam protons are slowed down below interaction threshold
by ionization before they are able to interact. Make a test
at a higher energy (e.g. 200 MeV) and you will certainly get some interactions.

Kind regards,

Received on Tue Aug 16 2011 - 17:35:09 CEST

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