|Message: neutron inelastic scattering on 127I||Not Logged In (login)|
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when simulating the energy spectrum registered by a NaI detector for a 252Cf neutron source, the "peak" due to the inelastic scattering of neutrons leaving 127I nuclides at its first excited state appear shifted to left.
To study the problem, I have created a quasi-infinite ideal detector made 100% of 127I and simulated only inelastic interactions for 1 MeV neutrons. I have registered separately energy deposited by electron/gammas and by I recoils in just the first neutron scattering, I attach the corresponding spectra expressed in counts/keV. I expected to find in the electron/gamma spectrum lines associated to the excited nuclear states of 127I (58, 203, 375, 418, 618 keV,... following http://ie.lbl.gov/TOI2003/LevelSearch.asp), but as you can see at least the first four lines appear shifted to left about 16 keV. I have checked the file /data/PhotonEvaporation2.1/z53.a127 and the energies of the nuclear levels seem OK. There may be some missing energy in the nuclear deexcitation? I am using geant4.9.4.p01 and G4NDL3.14.
Thank you very much, best regards, Susana Cebrian
Attachment: http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2012/11/27/08.40-19613-lisis_Neutrones_spc_e.txt http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2012/11/27/08.40-2238-lisis_Neutrones_spc_i.txt
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