Question on decay TGeoElementRN

Hi all

I am looking at radioactive nuclei inventory in radioactive sources. In the example below I wanted to know what would be the decay/buildup for an americium source.
Here is my very simple example, in this case I am only looking at how is Am241 decaying, simple solution of Bateman equation for the parent nuclei which should be of the form 1exp (-lambda .t)
or in this case the solution which is proposed is N[95-Am-241]/N[95-Am-241] = 1
exp(-7.35294e-11*t) which correspond to exp(-1/ T[size=59]1/2[/size] . t) , there is a ln(2) missing I have the impression. lambda = log(2)/ T1/2

TGeoManager *geom = new TGeoManager("","");
TGeoElementTable *table = geom->GetElementTable();
TGeoElementRN *Am241 = table->GetElementRN(241,95); // A,Z
TGeoMaterial *mat = new TGeoMaterial(“Am241”, Am241, 2.0);
TObjArray *vect = new TObjArray();
TGeoElement el = (TGeoElement)vect->At(0);
TGeoElementRN *elem = (TGeoElementRN *)el;

95-Am-241 ENDF=952410; A=241; Z=95; Iso=0; Level=0[MeV]; Dmass=52.929[MeV];
J/P=5/2-; Abund=0; Htox=3.9e-05; Itox=2e-07; Stat=0
Decay modes:
SpontFiss Diso: 0 BR: 0.000% Qval: 207
Alpha Diso: 0 BR: 100.000% Qval: 5.6378
n entries : 14
N[95-Am-241]/N[95-Am-241] = 1exp(-7.35294e-11t)

Please let me know if I have missing a point but my impression is that there is an error.

Thanks in advance


Andrei Gheata will answer your question later today


Hi Joachim,

This problem was already reported some time ago and fixed by Mihaela: