Re: SCORE estimator

From: Alberto Fasso' <fasso_at_slac.stanford.edu>
Date: Mon, 15 Aug 2011 14:10:38 -0700 (PDT)

Dear Mina,

> Looks like the SCORE estimator's behaviour is different than the other estima$
> only four distributions (in total) can be scored via one or more SCORE cards.$
> to look at more distributions via a SCORE card, they need to run the same inp$
> SCORE card.

yes, if you look at the description of the SCORE command on the manual, you
will find a Note which says:

2) SCORE is one of the oldest FLUKA commands, which has been kept unchanged
because of its simplicity and easiness of use. On the other hand, because it
lacks the flexible memory allocation of all other scoring options, there is
presently room for only 4 types of particles. Therefore, only the 4 first valid
WHAT-parameters are retained.

However, if you want to score per region avoiding the limit of 4, there is a
less simple, but more powerful command. You can use USRBIN with WHAT(1) = 2 or
12. As the manual says, you will get "Mesh: by region (1 bin corresponds to n
regions, with n = 1 to 3)".
With this choice, WHAT(4) is the last region of the first set, WHAT(5) the
last of the second set, and WHAT(6) the last of the third set.
In the continuation card, WHAT(1) is the first region of the first set,
WHAT(2) the first region of the second set, and WHAT(3) the first region of the
third set; WHAT(4) is step increment for going from the first to the last
region of the first region set, etc.
In addition, USRBIN per region allows you to score not only energy deposition
and stars, as SCORE, but also all kind of quantities, for instance fluence.
Read carefully the manual. Note, however, that this option does not offer the
possibility to normalize the results per unit volume: if desired, you need
to do it yourself off-line.

Best wishes to you too

Alberto

On Mon, 15 Aug 2011, Mina Nozar wrote:

> Dear Alberto,
>
> Thank you very much for the explanations.
>
> Looks like the SCORE estimator's behaviour is different than the other estimators, in the sense that
> only four distributions (in total) can be scored via one or more SCORE cards. So if a user wishes
> to look at more distributions via a SCORE card, they need to run the same input file with different
> SCORE card.
>
> Thank you for explaining what is SCORED if I use BEAMPART. Your explanation is clear and I
> understand it now.
>
> Thank you for your suggestion on my issue with no interactions in the setup I described. I had tried
> your suggestion, as well as changing the beam particle to protons, changing the material is some of
> the regions, and starting the beam half way through the target. I was able to find the problem by
> simplifying the input (geom and physics). The problem was with the RADDECAY settings, specifically,
> with the 99999 setting for WHAT(5) of RADDECAY card. As I understand it, this WHAT allows one to
> adjust (even override) the transport cuts for e+/- and g for prompt production as well as for the
> ones produced as decay products. I had set the e+/-, and g transport and production energy cutoffs
> to 100 keV using the EMF card. This setting was effectively killing all the photons produced in the
> Ta converter.
>
> Best wishes,
> Mina
>
>
> On 11-08-14 02:28 PM, Alberto Fasso' wrote:
>> 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,
>>
>> Alberto
>>
>
>

-- 
Alberto Fasso`
SLAC-RP, MS 48, 2575 Sand Hill Road, Menlo Park CA 94025
Phone: (1 650) 926 4762   Fax: (1 650) 926 3569
fasso_at_slac.stanford.edu
Received on Tue Aug 16 2011 - 10:19:26 CEST

This archive was generated by hypermail 2.2.0 : Tue Aug 16 2011 - 10:19:26 CEST