From: Giuseppe Battistoni (Giuseppe.Battistoni@mi.infn.it)
Date: Thu Mar 22 2007 - 16:53:29 CET
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
1) the lowest one: nuclear evaporation peak
2) close to 500 MeV/c: the so called quasi-elastic peak
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
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