Re: RE: Plotting USRBDX with one angular bin

From: Nicole Patricia Lee Pratt-Boyden (
Date: Thu Sep 21 2006 - 15:41:37 CEST

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    First off a quick apology in that, yes, I did wind up giving the wrong
    example. To score photons the card used was:

    USRBDX 101.0 7.0 -48.0 3.0 4.0 400.0 PH-0m
    USRBDX 6.5E-4 2.5E-4 8.0 0.0 1. &

    Thanks for clearing up the 2pi/4pi/neither question. I too was a bit
    thrown by the manual as I hadn't realised that the notes for the USRBDX
    card referred to the raw data only, not the output from the usxsuw

    Really appreciate all the pointers. Best regards,


    Etam Noah Messomo wrote:

    >I've just started using FLUKA and have been trying USRBDX for something
    >slightly different, tracking one-way energy flows across boundaries
    >(particle type is 208). I also started using fluence but found out that
    >with FLUKA, fluence isn't the time integral of flux, but is rather
    >related to the normal of the surface/boundary where the detector is
    >defined. If you simply want to score neutrons with no further
    >information on their directions, which is what I naively assume since
    >you have just one solid angle bin, you have to use current (FLUKA
    >'current' has no relationship with time). You then simply count the
    >number of neutrons crossing a given surface. (Please ignore all the
    >above if you know what you're doing and you're sure you have to use
    >In my case, I also left the detector area at the default value of 1.0 so
    >that I was counting the total energy crossing the surface without having
    >to normalise to cm^2 (personal choice).
    >Having used usxsuw, I found that the values returned only have to be
    >multiplied by the energy bin width (in your case 5e-5), and not by the
    >solid angle (I did not multiply by 2*pi). I had manually defined 2*pi as
    >the what(4) parameter in the continuation card (ie.e.. I wrote down
    >manually 6.2831853 which is meant to be the default anyway).
    >This is slightly different to Sebastien's answer, who suggests also
    >multiplying by 2*pi (which is what is written in the manual). I have to
    >say that my energies add up when I DO NOT multiply by the 2*pi.
    >Let me know if this is of any use to you.
    >Etam Noah
    >-----Original Message-----
    >[] On Behalf Of Nicole
    >Patricia Lee Pratt-Boyden
    >Sent: Tuesday, September 19, 2006 3:27 PM
    >Subject: Plotting USRBDX with one angular bin
    >I'm using a USRBDX card to score neutron fluence (linear angular and
    >energy bins). The programme seems to be running fine, and I'm compiling
    >the data with the usxsuw.f programme.
    >I asked for eight energy bins, and one angular bin.
    >USRBDX 101.0 7.0 -48.0 3.0 4.0 400.0
    >USRBDX 6.5E-4 2.5E-4 8.0 0.0 1. &
    >The *_tab file only returns the differential fluence integrated over
    >solid angle; there are no double differential values returned at all, no
    >mention of solid angle boundaries.
    >Assuming this is fine, do I still need to multiply the differential
    >values by 2PI (one-way scoring) in order to get diff. fluence in
    >particles/GeV/cm^2/primary, or do I only do this if I want fluence
    >Apologies if this is extremely simple, I was just thrown by the lack of
    >any information for the double differential! Best regards,
    >Nicole Pratt-Boyden.

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