Hi all, I have checked branching ratio for 59.5 keV gamma from Am241 (35.9 % on NuDat tables) and I have obtained 51.8% with the example rdecay01 (in extended/radioactivedecay). This problem was reported in 2007 and continues with the latest versions of G4 and Radioactive Decay. Michael Maire found the same result as me: http://hypernews.slac.stanford.edu/HyperNews/geant4/get/hadronprocess/786/3/2/1.html Thanks, Carlos Montes
Dear Carlos, After analysis of the code and of the photo-evaporation nuclear data file we have found two issues: 1)When the internal conversion is switched on the code is working as expected. The reason that the 59.5 keV gamma intensity is 51.8% rather than 35.9 % comes from the fact that in the photo G4 evaporation data file for Np237, the internal conversion factor (colum7) is different than in Nudat. This factor represents the ratio of the intensity of internal conversion e- over the gamma intensity.If you replace in the file z93.a237 the first 13 lines by the following lines: 3.319640e+01 3.319640e+01 0.000e+00 -1 5.40e-11 3.50 1.850e+02 0.000e+00 4.680e-01 1.410e-01 8.750e-02 1.130e-01 3.750e-02 2.425e-02 4.595e-04 2.830e-04 6.350e-02 5.954120e+01 2.634480e+01 6.690e+00 1 6.70e-08 2.50 8.000e+00 0.000e+00 1.253e-01 2.462e-01 3.224e-01 3.529e-02 4.423e-02 6.144e-02 1.867e-02 2.266e-02 6.187e-02 5.954120e+01 5.954120e+01 1.000e+02 1 6.70e-08 2.50 1.160e+00 0.000e+00 2.468e-01 2.265e-01 2.284e-01 5.967e-02 4.843e-02 5.230e-02 7.164e-03 8.103e-03 6.096e-02 7.592000e+01 4.273000e+01 1.000e+02 1 5.60e-11 4.50 8.000e+01 0.000e+00 1.954e-01 2.392e-01 2.662e-01 4.900e-02 4.792e-02 5.715e-02 1.077e-02 1.254e-02 6.108e-02 7.592000e+01 7.580000e+01 1.100e+01 1 5.60e-11 4.50 0.000e+00 0.000e+00 2.854e-01 2.156e-01 2.021e-01 6.736e-02 4.792e-02 4.792e-02 5.208e-03 5.799e-03 6.076e-02 1.029600e+02 2.703000e+01 0.000e+00 1 8.00e-11 3.50 4.300e+00 0.000e+00 1.291e-01 2.465e-01 3.209e-01 3.581e-02 4.442e-02 6.116e-02 1.812e-02 2.188e-02 6.186e-02 1.029600e+02 4.342300e+01 1.000e+02 -1 8.00e-11 3.50 1.670e+02 0.000e+00 2.105e-01 2.635e-01 2.122e-01 5.122e-02 7.072e-02 5.967e-02 9.724e-04 6.022e-04 6.519e-02 1.029600e+02 6.976000e+01 4.000e+00 1 8.00e-11 3.50 3.360e-01 0.000e+00 2.723e-01 2.198e-01 2.112e-01 6.480e-02 4.804e-02 4.944e-02 5.838e-03 6.508e-03 6.089e-02 1.029600e+02 1.029800e+02 2.670e+01 1 8.00e-11 3.50 1.210e-01 0.000e+00 3.333e-01 1.992e-01 1.713e-01 7.752e-02 4.620e-02 4.217e-02 3.434e-03 3.752e-03 6.093e-02 1.300000e+02 5.400000e+01 0.000e+00 1 0.00e+00 5.50 7.030e-01 0.000e+00 2.319e-01 2.304e-01 2.404e-01 5.633e-02 4.836e-02 5.377e-02 8.094e-03 9.232e-03 6.088e-02 1.300000e+02 9.670000e+01 0.000e+00 1 0.00e+00 5.50 1.520e-01 0.000e+00 3.237e-01 2.033e-01 1.770e-01 7.566e-02 4.664e-02 4.336e-02 3.750e-03 4.105e-03 6.092e-02 1.585100e+02 5.556000e+01 8.900e+01 -1 0.00e+00 4.50 6.700e+01 0.000e+00 2.448e-01 2.545e-01 1.895e-01 5.947e-02 6.819e-02 5.339e-02 8.700e-04 5.214e-04 6.515e-02 1.585100e+02 9.897000e+01 1.000e+02 -2 0.00e+00 4.50 1.560e+01 0.000e+00 1.982e-02 3.916e-01 2.641e-01 6.287e-03 1.054e-01 7.545e-02 1.150e-03 6.407e-04 6.707e-02 you should get ~ the 35.9 % intensity of 59.5 keV gamma. The conversion coefficient are in the G4 evaporation data file in the 7th column while in nudat2 they are in the last column of the gamma information table. (Second table from the top for the Nuclear Levels and Gammas Search). We are discussing the issue on how to produce a new dataset in accordance with nudat2. 2) When internal conversion is switched off the gamma production is not correct as any production of IC e- is replaced by a gamma increasing therefore the gamma intensity is not the expected one. We are working on this issue too. So at the moment you should only use the mode where the Internal conversion is switched on. Best regards Laurent
Created attachment 142 [details] Comparison nudat2 and G4 gamma intensity from Am241 decay. Comparison nudat2 and G4 gamma intensity from Am241 decay.
Hi, The problem has been solved by updating the Nu237 evaporation datafile according to nudat2. Best regards L. Desorgher
