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Sad Wrong gamma spectrum of Yb-169 with rdecay01 example 

Forum: Hadronic Processes
Date: 23 Oct, 2015
From: Alexey Solovyev <Alexey Solovyev>

I tried to simulate Yb-169 decay using rdecay01 example (/gun/ion 70 169) and got the following spectrum (see attachment). There is strong line at about 63 keV as intended, but all another lines seems wrong - next top line at about 300 keV and lines at e.g. at 109, 130, 177, 197 keV are almost zero. This doesn't correspond to any data I found: nor measured (LBNL, LANL, ENSDF, RIAR), nor recommended (ICRU, TORI), nor even data at CERN website (https://espace.cern.ch/ICTR-PHE2012-slides/Session%202%20Radioisotopes%20in%20diagnostics%20and%20therapy/akulinichev_cern_2012.pdf).

Tried to use Geant4-10.0, Geant4-10.1.p02 both on Windows and Linux with RadioactiveDecay 3.2, 3.6, 4.0, 4.2 (almost all combinations). Some differences between them also found but the main case still persists: all the upper lines except 63 keV seems to be wrong.

While trying to figure what happens also found that turning some options inside PhysicsList of rdecay01 example resulting in slight shift of lines (see _dcOptions attachement). As I may suggest, the wrong part is somewhere inside the excitation of 169Tm[...] mechanisms.

Also, kind of another story, but this decay spectrum cause about 4 times higher absorbed dose at my media (after modifying the example, all the above were about unmodified example) than conventional spectrum based on /gps/hist with gamma lines appropriate to measurement.

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2015/10/23/03.46-20767-Yb169.png
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2015/10/23/04.01-12267-Yb169_dcOptions.png

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1 None: Re: Wrong gamma spectrum of Yb-169 with rdecay01 example   (michel maire - 24 Oct, 2015)
1 None: Re: Wrong gamma spectrum of Yb-169 with rdecay01 example   (Alexey Solovyev - 26 Oct, 2015)
2 None: Re: Wrong gamma spectrum of Yb-169 with rdecay01 example   (Alexey Solovyev - 27 Oct, 2015)
1 None: Re: Wrong gamma spectrum of Yb-169 with rdecay01 example   (Alexey Solovyev - 27 Oct, 2015)
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