Re: Plotting USRBDX with one angular bin

From: Alberto Fasso' (fasso@SLAC.Stanford.EDU)
Date: Tue Sep 19 2006 - 16:17:58 CEST

  • Next message: Sebastien WURTH: "Re: Plotting USRBDX with one angular bin"

    Be careful: the manual says that you must multiply by 2 pi or 4 pi,
    but assuming that you do the integration yourself. The usxsuw program
    takes already care of that, so you must not do it again

    Alberto

    On Tue, 19 Sep 2006, Sebastien WURTH wrote:

    > Hello,
    >
    > 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 :
    > *********
    > Notes
    > 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.
    > Sebastien.
    >
    >
    >
    >
    > Nicole Patricia Lee Pratt-Boyden a écrit :
    >
    > >Hello,
    > >
    > >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
    > >PH-199m
    > >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
    > >(/cm^2/pr)?
    > >
    > >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.
    > >
    > >
    >
    >
    >

    -- 
    Alberto Fassò
    SLAC-RP, MS 48, 2575 Sand Hill Road, Menlo Park CA 94025
    Phone: (1 650) 926 4762   Fax: (1 650) 926 3569
    fasso@slac.stanford.edu
    

  • Next message: Sebastien WURTH: "Re: Plotting USRBDX with one angular bin"

    This archive was generated by hypermail 2.1.6 : Tue Sep 19 2006 - 16:36:33 CEST