Modifying half-life of No252 in rdecay01 example

Geant4 Version: 11.2.1
Operating System: macOS Sonoma 14.4.1
Compiler/Version: C++98
CMake Version: 3.29.2

I am having issues altering the half-lives of nuclear excited states in Geant. I think the best way to illustrate my issue is through the rdecay01 example in 11.2.1. If I run the No252.mac file with no modifications, I get the appropriate mean life listed in the terminal output of the macro. However, this mean life (3.52 s) does not change even when I edit the UserData/UserEvapData_z102.a252 file, stored in the rdecay01 directory, to increase the half-life of the ground state. The terminal still gives the same mean life of 3.52 s. This is a general issue I am having with Geant, both with v11.2.1 and older versions. I seem unable to control the half-life of metastable states by editing the photon evaporation files. Are there any solutions here?

@MarkMurdy

Hello,

Have you defined the decay file in the macro you used “No252.mac”.
In case not defined, please add it in macro;

 /grdm/setRadioactiveDecayFile path2/filename

#OR 

 /grdm/setPhotoEvaporationFile path2/filename

VRS

I am using that line, with the exception that the most recent version of Geant uses /process/had/rdm/ instead of /grdm/. I am referring to the following line in the rdecay01 example that comes with Geant:

/process/had/rdm/setPhotoEvaporationFile 102 252 ../UserData/UserEvapData_z102.a252

When I try updating the UserEvapData_z102.a252 file, it has no effect on the code output.

The complete script is here:

# macro for rdecay01
#
# to read user's data file
#
/control/cout/ignoreThreadsExcept 0
#
# Set a very high time threshold to allow all decays to happen
/process/had/rdm/thresholdForVeryLongDecayTime 1.0e+60 year
#
/process/had/rdm/setPhotoEvaporationFile 102 252 ../UserData/UserEvapData_z102.a252
#
/gun/particle ion
/gun/ion 102 252 0 3.2070e+02 
#
/run/beamOn 100000

RadioactiveDecay process needs not only RadioactiveDecay and PhotonEvaporation datasets, but also G4ENSDFSTATE.
In particular, timeLife of isotopes are read from G4ENSDFSTATE and there is no way for a user to change it, unless to modify directly G4ENSDFSTATE.

So there is no way via macros to update the lifetimes of metastable states. We just need to directly modify the source files in G4ENSDFSTATE?

I my knowledge, yes.
You can ask details or confirmation directly to Alberto.Ribon@cern.ch or luis.sarmiento_pico@hep.lu.se or Vladimir.Ivantchenko@cern.ch