Re: Scoring DOSE-EQ from Cs-137 source

Dear Robin,
  about the first point that you posted (pSv/pr->pSv/s) I agree with you,
about the settings regarding the EM transport, I suggest you to use the
EM-CASCA DEFAULTS and the CARD EMFCUT for changing the energy threshold
for electron, positron and photon production (SDUM='PROD-CUT') and the
electron, positron and photon transport energy cut-off using the CARD
EMFCUT (SDUM= blank).
Ciao
Andrea

> Fluka Experts,
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> I am trying to score to Dose Equivalent in uSv/hr at a locations 5cm
> from the surface of a source holder designed for a 1 Ci Cs-137 source. I
> have tried as hard as I can to glean the information I need from the
> manual and previous postings to this list but I fear I still need some
> clarifications.
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> I have setup and tested the attached input/geometry/flair files and I
> believe I am on the right track.
>
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> I have an isotropic beam of 662 keV PHOTONS located at the planned
> location of the Cs-137 source and the geometry plots as expected using
> flair.
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> I am using a USRBIN for scoring using a XYZ cube that fully includes the
> space of interest with 100 division on each axis.
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> I am scoring the DOSE-EQ generalised particle.
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> This setup runs successfully and generates output.
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> My question is regarding the meaning of the value for each USRBIN
> scoring volume.
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> My current understanding is that this is pSv/primary beam particle, and
> that to convert this to uSv/hr for a 1 Ci source I would need to
> multiply this value by 37e9*85% (disintegrations per seconds for 1Ci *
> by the percentage of disintegrations that produce the gamma of interest)
> to determine the pSv/s for 1Ci from the 662 keV gamma rays. I do this
> and the results are relatively close to simple hand calculations with
> only basic corrections for build up. Is this generally on the right
> track.
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>
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> Secondly are there any settings with regard to EM transport that I am
> missing that will greatly change the output of the USRBIN scoring.
>
>
>
> Thanks in advance.
>
>
>
> Robin Sheehy
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Received on Thu Jul 09 2009 - 15:22:56 CEST