Created attachment 356 [details] Macro file for example Hadr04 Hi, I'm simulating the neutron capture of thermal neutrons on Gd. Up to version 10.1, conversion electrons were correctly produced when setting the flag setenv G4NEUTRONHP_USE_ONLY_PHOTONEVAPORATION=1, from version 10.1.p01 this is not the case, just the prompt gammas are emitted. The problem can be reproduced on lxplus with example Hadr04 and the run01.mac file that I attached. Running Hadr04 with Geant4 10.1 I get the following output: ************************************* The run is 100 neutron of 25 meV through 50 cm of Gd (density: 7.9 g/cm3 ) Process calls frequency : nCapture= 100 List of generated particles: Gd156: 100 Emean = 39.964 eV ( 1.3963 eV --> 220.04 eV ) e-: 132 Emean = 132.5 keV ( 38.724 keV --> 649.84 keV) gamma: 1211 Emean = 690.46 keV ( 7.2429 keV --> 5.2223 MeV) On Geant4 10.1.p02: ************************************ The run is 100 neutron of 25 meV through 50 cm of Gd (density: 7.9 g/cm3 ) Process calls frequency : nCapture= 100 List of generated particles: Gd156: 100 Emean = 126.37 eV ( 8.0191 eV --> 238.11 eV ) e-: 1 Emean = 602.13 keV ( 602.13 keV --> 602.13 keV) gamma: 299 Emean = 2.8528 MeV ( 481 keV --> 5.7787 MeV) ************************************* There are no conversion electrons produced in 10.1.p02. Cheers Dorothea
Hello, sorry for the late comment but only now a patch to the release 10.2 is ready. In this patch we have addressed several problems for radioactive decay model and for gamma de-excitation found in the release 10.2. If you can switch to 10.2p01 will you still have this problem or it is fixed? We did not try to fix 10.1 release, so the recent patch 10.1p03 does not include any fix to radioactive decay, because this is difficult to do without interface change that we use to avoid in patches. VI
Hello, we close this bug report, because we cannot provide a fix with no interface change. The code should work after 10.2p01. VI
Created attachment 416 [details] Comparison Gd conversion electrons in different Geant4 version
I finally found the time to compare the Gd physics concerning internal conversion electrons in Geant4 10.1, 10.2 and 10.2.p02 (see attached picture). In Geant4 10.1 there are 1.32 conversion electrons per neutron in 155 Gd, and 0.67 conversion electrons per neutron in 157 Gd. In Geant4 10.2, no conversion electrons at all are produced. In Geant4 10.2.p02, independent on whether we use PhotoEvaporation3.2 or PhotoEvaporation4.0 data, or whether we use the new flag SetAugerCascade(true), we get 0.7 conversion electrons per neutron in 155 Gd, and 0.73 conversion electrons per neutron in 157 Gd. In Geant4 10.2.p02 it basically does not happen any more that more than one conversion electron is produced per neutron. If one compares the values with the literature (155 Gd: 0.61-0.79 conversion electrons per neutron, 157Gd: 0.60-0.61 conversion electrons per neutron), one notices that the number of conversion electrons per neutron for 155 Gd seems to be correct, and just slightly too high for 157 Gd. In total, huge improvement compared to previous versions. Thanks a lot!
