Re: Kinks in neutron momentum distribution

From: Giuseppe Battistoni (
Date: Thu Mar 22 2007 - 16:53:29 CET

  • Next message: Alberto Fasso': "Re: Thermal Neutron Capture Gammas"

    Hi Joseph,
    I believe that you should not worry about those kinks. In part they seem
    ugly because of the way you are plotting them.
    In order to understand better neutron
    structures you should plot using
    lethargy (E dN/dE) instead of momentum, and also log. binning (a part the
    region <19.6 MeV where one must stick to the width of our 72 energy
    However the 2 structures that you see should be related to two real
    physics issues:
    1) the lowest one: nuclear evaporation peak
    2) close to 500 MeV/c: the so called quasi-elastic peak

    Best regards

            Giuseppe Battistoni

    On Wed, 21 Mar 2007, Joseph Comfort wrote:

    > I am looking a particle production for the 30-GeV proton beam on a
    > nickel target, about 5 cm thick. We are especially interested in
    > neutrons, including low-energy ones. I am using the PRECISION option
    > (and no LOW-BIAS card).
    > Attached is a pdf figure of an expanded portion of the neutron (and
    > photon) momentum distribution. There are a couple of kinks near 200
    > MeV/c and 1 GeV/c. The lower one is probably the break at 19.6 MeV
    > energy; the second one is near 400-500 MeV.
    > Do the kinks represent changes in algorithms. How seriously should I
    > take them? Are there ways to smooth them out? I will probably
    > parameterize the distribution in some way, after acquiring some more
    > events. It is not clear if I need to incorporate the kinks, or go
    > smoothly across them.
    > Thank you,
    > Joe Comfort

  • Next message: Alberto Fasso': "Re: Thermal Neutron Capture Gammas"

    This archive was generated by hypermail 2.1.6 : Thu Mar 22 2007 - 17:48:11 CET