Errors in Pa233 decay data


As introduced by EneaMapelli in the post of 25 July, there are some errors in the decay data of the Pa233.

In fact, if i compare the simulated spectrum with the measured one there are a lot of differences.
These problems were not present in a previous version of the photonevaporation data (i don’t remember the version, but published with Geant 4.9.6, now i’m on version 5.3).

A big one (from z92.a233 photonevaporation data):

There are a transition from the 415.758 keV level of the U233 with a relative branching ratio of 100% (so equal to 1.73 % of absolute BR from ENSDF data) with an energy of 61.968 keV that has almost 100 % probability to make internal conversion (IC coefficient 5908).
This decay populates the 353.79 keV level. This level should not be populated with a so high BR, (in fact it is not present in the simplified decay scheme of Pa233-U233).
This level decays (with a very high BR) with the emission of gamma-rays (198.56, 261.63, 313.44) that are not present in the measured spectrum.

If i calculate the BR of the 313.44 keV gamma ray, i obtain a 0.84% of absolute BR, but the ENSDF indicate a BR of 0.0139% for this gamma transition.

I didn’t check but should be other errors in these data, because, as mentioned by EneaMapelli, there also a higher population of the 298.81 keV level that seems to be not correlated with the transition mentioned above.

I hope that the authors could make a check of these data as soon as possible because the simulation is very far away from the experimental data.

Thank you very much for your help


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Reporting in z92.a233 present in PhotonEvaporation5.2 the relative intensities present in PhotonEvaporation2.3 included in geant 9.6.p04 the simulation returns results compatible with the experimental measurements. I attach the modified file(.txt to be removed).z92.a233.txt (29.1 KB)


Thank you very much for providing fixed data file.We will try to include it in the next public release.



I have run a simulation with G4 10.6 but the problem is still present.
The PhotonEvaporation data of the U233 seems to be very different from the ENSDF data, in fact, the simulated spectrum is very different from the measured one.

I have attached a corrected file based on ENSDF data. Note that I have corrected only the main discrepancies: not the transition from the high energy levels because they have an extremely low branching ratio, and there are still some differences in some peaks intensity. (eg. 387 and 330 keV)

I have attached also a spectrum of the simulation of decay of Pa233 into U233 with the original (blue) and the modified (red) data.
I have also attached a measured spectrum of the Pa233 decay.

I hope that this could help to fix the issue

Thank you

z92.a233.txt (29.1 KB)