Re: Plotting USRBDX with one angular bin

From: Sebastien WURTH (
Date: Tue Sep 19 2006 - 15:59:43 CEST

  • Next message: Alberto Fasso': "Re: Plotting USRBDX with one angular bin"


    In your example, you cannot have a neutron fluence, you put WHAT(2) =
    7.0 in your first USRBDX card, this would give you photon fluence (maybe
    you choose only the wrong example to illustrate).
    To answer your question (I was asking me the same one once), I quote the
    manual from USRBDX part :
    1. IMPORTANT! The results of a USRBDX boundary crossing estimator are
    always given as double differential
    distributions of fluence (or current) in energy and solid angle, in
    units of cm−2 GeV−1 sr−1 per incident primary,
    even when only 1 interval (bin) has been requested, which is often the
    case for angular distributions.
    Thus, for example, when requesting a fluence or current energy spectrum,
    with no angular distribution, to
    obtain integral binned results (fluence or current in cm−2 per energy
    bin per primary) one must multiply the
    value of each energy bin by the width of the bin (even for logarithmic
    binning), and by 2 pi or 4 pi (depending
    on whether one-way or two-way scoring has been requested).[...]

    Best Regards.

    Nicole Patricia Lee Pratt-Boyden a écrit :

    >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.

  • Next message: Alberto Fasso': "Re: Plotting USRBDX with one angular bin"

    This archive was generated by hypermail 2.1.6 : Tue Sep 19 2006 - 16:23:54 CEST