|Message: Example Hadr03: Conversion electrons and gammas after neutron capture incorrect||Not Logged In (login)|
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using the attached macro file for example Hard03 in Geant4 10.2.p02 (PhotoEvaporation3.2), I get 2 possible nuclear reactions for the neutron capture in Gd:
List of nuclear reactions:
neutron + Gd --> N gamma + Gd158: 27338 Q = 7.9374 MeV neutron + Gd --> N gamma + e- + Gd158: 72281 Q = 7.9161 MeV neutron + Gd --> neutron + Gd157: 381 Q = 0.038964 eV
Number of gamma: N = 1 --> 2
Together with the flag G4NEUTRONHP_USE_ONLY_PHOTONEVAPORATION=1, I get the particles below. There are conversion electrons, but only from the first excitation level. The other levels are missing. For all other levels I get only gammas. In total, compared to the literature, the number of conversion electrons is slightly too high and the number of gammas too low.
List of generated particles: Gd157: 381 Emean = 0.038891 eV ( 0.00096043 eV --> 0.19133 eV ) Gd158: 99619 Emean = 210.68 eV ( 194.17 eV --> 226.3 eV ) e-: 72281 Emean = 58.253 keV ( 29.264 keV --> 79.148 keV) gamma: 111468 Emean = 7.0419 MeV ( 79.508 keV --> 7.9372 MeV)
In Geant4 10.1 (PhotoEvaporation3.2) on the other hand, there were nuclear reactions with 2,3 and 4 conversion electrons, that are missing in the newest Geant4 version.
List of nuclear reactions:
neutron + Gd157 --> N gamma + 2 e- + Gd158: 8465 Q = 7.9374 MeV neutron + Gd157 --> N gamma + 3 e- + Gd158: 22 Q = 7.9374 MeV neutron + Gd157 --> N gamma + 4 e- + Gd158: 1 Q = 7.9374 MeV neutron + Gd157 --> N gamma + Gd158: 56274 Q = 7.9374 MeV neutron + Gd157 --> N gamma + e- + Gd158: 34882 Q = 7.9374 MeV neutron + Gd157 --> neutron + Gd157: 356 Q = 0.035456 eV
Number of gamma: N = 2 --> 7
The generated particles in Geant4 10.1 contained also conversion electrons from higher levels, and lower energetic gammas. Further, the total number of conversion electrons was correct in Geant4 10.1 compared to the literature, and also the number of gammas.
List of generated particles: Gd157: 356 Emean = 0.035851 eV ( 0.0007276 eV --> 0.16493 eV ) Gd158: 99644 Emean = 106.47 eV ( 0.018335 eV --> 227.05 eV ) e-: 51882 Emean = 56.753 keV ( 29.264 keV --> 1.1358 MeV) gamma: 242211 Emean = 3.2532 MeV ( 7.2426 keV --> 7.3982 MeV)
What has been changed in the latest version? Where have the nuclear reactions that produced 2,3 or 4 conversion electrons gone to? For me it looks like that in Geant4 10.2.p02 the excited 158Gd now de-excites down to the first excitation level, and for this level always produces a K,L or M shell conversion electrons. Somehow the ICC in the PhotoEvaporation3.2 data are ignored.