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Photons at low energies? [message #4986]

Tue, 28 August 2007 17:19

StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino

first-grade participant

From: *physik.uni-giessen.de

Hello,
Chris has found a particular behaviour of the cluster response for low energy photons...

If you run the EMC simulation (G3) with photons at 200 MeV in the theta range of [40°-140°], and then you perform the full recontruction, this is the plot you get as cluster energy:

index.php?t=getfile&id=3812&private=0

(the plot was made with 10k events, but even with 1k events you can see the same). I check with the stable version 1_0_0 and with the last svn update. It seems that the energy response is discrete, with an energy spacing of ~ 3 MeV. I checked with 400 MeV or higher energies but it seems it is not present there, neither increasing the binning (so it is not an effect of the histogram).

Maybe some problem with digitization?