| Summary: | Problems with photon deexcitation energy conservation after EC decay & strange decay nuclear dexcitation gamma-ray energies | ||
|---|---|---|---|
| Product: | Geant4 | Reporter: | Andreas <zog> |
| Component: | processes/hadronic/models/de_excitation | Assignee: | dennis.herbert.wright |
| Status: | RESOLVED FIXED | ||
| Severity: | major | CC: | dennis.herbert.wright, zog |
| Priority: | P5 | ||
| Version: | 10.1 | ||
| Hardware: | All | ||
| OS: | All | ||
| Attachments: |
Modified rdecay01 example
Hacked G4UAtomicDeexcitation.cc file |
||
Created attachment 349 [details]
Hacked G4UAtomicDeexcitation.cc file
This has now been fixed using Andreas' suggested method. Energy non-conservation is now usually 30 eV or less. |
Created attachment 348 [details] Modified rdecay01 example Hello, Attached is a modified version of the rdecay01 example which shows the issue. It has been run with Geant4 10.01p01 ("rdecay01 singleDecay.mac"). The considered isotope is Co-57. Co-57 decays via electron capture to Fe-57[136.5keV] (99.8% probablity) and then deexcites via the emission of one 136.5 keV photon, or via one 122.1 and one 14.4 keV photons. Since it decays via electron capture, also fluresence photons/Auger electrons corresponding to electron capture from the K-shell (binding energy: 7.1 keV) or the L-shells are expected. Thus for the *dominating* case, one would expect a total energy release of 136.478 keV + 7.088 keV = 143.566 keV. Running the above example, however, this total energy varies between 141 and 143 keV in the output (look for "Total deposit:" in the dumped output). The reason is in "G4UAtomicDeexcitation::GenerateParticles" and related functions, which do not generate the full amount of fluoresence photons / Auger electrons as required by the energy of the vacancy in the K shell from electron capture. Attached is a "hacked" version of G4UAtomicDeexcitation.cc which generates a dummy electron for the missing energy between binding energy and total energy of generated fluoresence photons and Auger electrons to temporarily fix this issue. Recompiling and running the modified rdecay01 again, we get many more deposits at 143.566 keV and with energies corresponing to L-shell captures. However, there are still a few outlyers left. Some of them have 142.xxx keV energy deposits: Those events seem to have generated a 121 keV gamma-ray instead of a 122 or a 13.6 keV photon instead of a 14.4 keV photon... Which should not happen accrding to Firestone... If you have questions, feel free to ask. Thanks a lot, Andreas