Metastable states of Gd after thermal neutron capture

Hi all!

I’m trying to simulate the thermal neutron capture of Gd. This reaction produces Gd metastable and I would like to see the internal conversion electrons released when it returns to the ground state.

The problem I’m currently facing is that I don’t see any metastable states after neutron capture. I’m using the QGSP_BIC_HP physics list, in which I believe the G4RadioActiveDecay process is active, and version 10.6.1.

I’ve tried the example in extended/radioactivedecay/rdecay01. There I can put for example Gd158[233.1] and I see IC electrons. So, the problem seems to be that the nCapture process doesn’t create metastable states of Gd.

Should I add something to my physics list or do you know any other options?

Any advise would be very useful! Thanks!


Do you observe the same situation in case of using QGSP_BIC with active G4RadioActiveDecay process?

Yes, I tried with QGSP_BIC and G4RadioActiveDecay process. It was mention here: Can't get metastable levels of In during run.

But the result is the same. nCapture just creates Gd158 without metastable information.

Thanks for your reply!

The ENSDF database on which the PhotonEvaporation data files are based, is incomplete. There are no gamma lines, and therefore no internal conversion. Using other sources, like Nuclear Data Sheets and other articles, most of the missing lines can be added. I have done this for 158Gd and 156Gd. Still, not all the lines are there, but using the new files will improve the internal conversion rate.
If you want the files I can e-mail them to you.

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I didn’t know that! I’m rather new with geant4. If you can send me the files explaining briefly what should I do that would be great!. (In fact, it would be great to add the solution here so other people can see it).

Thanks again!