Re: USRBIN plot for low energy electrons

From: Alberto Fasso' <fasso_at_SLAC.Stanford.EDU>
Date: Thu, 4 Aug 2011 06:35:14 -0700 (PDT)

Dear Petwal,

when I read your email my first reaction was: "probably this user has
not set up
low enough electron energy cutoffs".
Instead, looking at your input, I see transport and production cutoffs
set with EMFCUT as low as 1 keV.
But these cutoffs are not doing the job, because you have forgotten to
specify
the materials (for production) and the regions (for transport) where
the cutoffs apply. Therefore, (see the manual) the production cutoff is
assigned only to material 3 (hydrogen) that you don't use, and the transport
cutoff is assigned only to region 2 (VOID) where it has no effect.
Check in your output a section containing something like:

   IRON
        Rho = 1.00000 g/cm**3 Rlc= 13.8385 cm
        Ae = 0.511999 MeV Ue = 5062.95 MeV
        Ap = 1.000000E-03 MeV Up = 5062.44 MeV
        dE/dx fluctuations activated for this medium, level 1
        below the threshold for explicit secondary electron production
       (up to 2I discrete levels, up to 2 K-edges)
1 Correspondence of regions and EMF-FLUKA material numbers and names:
         Region EMF FLUKA

            1 0 VACUUM 1 BLCKHOLE
       Ecut = 0.0000E+00 MeV, Pcut = 0.0000E+00 MeV, BIAS = F,
  Ray.....
            2 1 IRON 11 IRON
       Ecut = 5.1200E-01 MeV, Pcut = 1.0000E-03 MeV, BIAS = F,
  Ray.....

(the example pasted above does not refer to your case: it is just to
show you
how you can check the cutoffs which have been actually applied).
Ae is the production cutoff, expressed as TOTAL ENERGY (kinetic + mass
energy):
you will find it printed for each material. And Ecut is the transport
cutoff,
also expressed as TOTAL ENERGY, and it is printed for each region.

Why did you send the input file in Word format? If I had in text (ASCII)
format,
I could have run it and checked myself what cutoffs you got.

Alberto

On Thu, 4 Aug 2011, V.C.Petwal wrote:

> Dear Fluka users,
>
> I am interested to generate the depth dose profile of electrons beam in keV
> energy range.
>
> I have prepared a simple input file using flair.
> To start with incident energy is considered 700 keV , beam size 2 cm x 2cm
> normally incidenting on Al target. USRBIN card used to score energy in
> various cells. I am expecting the range of electron in Al 0.13 cm. But the
> userbin plot which is attached here with does not show any result.
>
> However when energy of incident electron is changed to 7 MeV, the observed
> depth dose profile is satisfactory. The userbin plot shows range of
> electron 1.4 cm which is OK).
>
> Could anybody help me in understanding the problem and generating the
> depth
> dose profile in the material at energy in 5 keV-800 keV range.
>
> The input file is also attached here with.
>
> Regards
> Petwal
>
>
> -----Original Message-----
> From: Giuseppe Battistoni [mailto:giuseppe.battistoni_at_mi.infn.it]
> Sent: Thursday, August 04, 2011 12:44 AM
> To: Vasilis Vlachoudis
> Cc: V.C.Petwal
> Subject: Re: USRBIN plot for low energy electrons
>
> I'm not finding this message.
> Please resend it
>
> Giuseppe
>
> On 03/08/2011 14:29, Vasilis Vlachoudis wrote:
>> Hi Giuseppe,
>>
>> Mr. Petwall send the last email to the list last week (as he claims) but
> it never appeared, could you please verify it.
>>
>> Vasilis Vlachoudis
>> Dep EN, CERN
>> CH-1211 GENEVA 23
>> SWITZERLAND
>>
>> Phone: +41-22 767 9851
>> GSM: +41-76 487 4378
>> Fax: +41-22 766 9644
>>
>>
>>
>>
>
>
>

-- 
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 Sat Aug 06 2011 - 13:37:08 CEST

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