Dear Geant4 developers, I was trying to use 'exrdm' example in order to get initial spectra for all the particles in the decay of Na-22. I have found that Radioactive Decay Module generates gamma's with the energy of 1567.7 keV. However, according to the NNDC internet data-base for Na-22, there is no gamma's with this energy. Looking at the library that has been supplied with Geant4 (version 4.9.2 with path p02) I have found that if I will modify the exiting file for the Radioactive Decay Library v3.2 to the one that I have included into this message I can remove the 1567.7 keV gamma line. I would be appreciated if someone more knowledgeable about the radioactive decay library would check data-file for Na-22 in the RadioactiveDecay3.2. Thank you in advance, Victor. 17 November, 2009 ---------------------- Dr. Victor V. GOLOVKO Queen’s University Department of Physics, Stirling Hall Kingston, Ontario, Canada K7L3N6 Phone: +1 613-533-2694 Fax: +1 613-533-6463 E-mail: vgolovko@owl.phy.queensu.ca
Created attachment 61 [details] proposed file for radioactive decay of Na-22
Dear Victor, I tried it and I could not reproduce the problem. Actually, the Q-value of the Na-22 decay is 2842.2 keV, so when the final state has excitation energy 1274.57 keV, the available energy for the beta+ decay should be 2842.2-1274.57 = 1567.63 keV, as reported in the original database file. I run a few 10000 events and I could find any 1567-keV gamma-ray emitted in the decay of Na-22. For example, for one single event I have e+: 269 keV --> 2 annihilation gammas 511 keV nu_e: 277 keV gamma: 1275 keV Ne22: 13 eV total: 2842 keV. You have with some probability (about 9%) mono-energetic 1.567-keV neutrinos, following electron capture, and no positrons. Ciao, Luciano
Dear Victor, Checked with version 9.3 and have found no 1567.7 keV gamma at all with 100000 Na-22 decays. This confirms the finding of Luciano. Regards Fan
