Spontaneous fission in GEANT4

Hi all!
I’m trying to simulate the spontaneous fission of Cf-252 and I’m interested in all the fission fragments, neutrons and gammas.
I’m using the physics lists G4RadioactiveDecayPhysics and G4HadronPhysicsQGSP_BERT_HP, but the isotope simply doesn’t do anything, it doesn’t even undergo alpha decay, which should happen ~96% of the times. I’m not sure that it is possible to simulate spontaneous fission at all in GEANT4, is it? If it is, which physics list should I use? I have the following environment variables defined: G4LEDATA, G4LEVELGAMMADATA, G4RADIOACTIVEDATA, G4ENSDFSTATEDATA, G4SAIDXSDATA, G4PARTICLEXSDATA, G4NEUTRONHPDATA, G4INCLDATA.
Thank for your help!


if you do not see even alpha decay this means something wrong. Please try out $G4INSTALL/examples/extended/radioactivedecay/rdecay01

Try to see what is given by this example and what is different in your application.


Thanks for your reply! I’ve had a look at the example, and it seems to me that is pretty similar. Also, I’m using the same code and physics I use with other radioactive isotopes, which have beta and alpha decays. What puzzles me is that if I simulate other isotopes that undergo alpha decay - for instance U-238 - it works fine. If I look at what is being simulated in the case of Cf-252, I see that the RadioactiveDecay process is called, but no secondaries appear (I attach the verbose output).

. I was wondering if there was anything special with this element; I’ve looked into data files in $G4INSTALL/data/RadioactiveDecay5.3, and apparently it is defined as any other isotope.

I know this is a very late reply, but the information is relevant to the original question.

First, spontaneous fission was not available until the 10.6 release. The Cf-252 should have been decaying entirely through th alpha channel.

Second, even in 10.6, spontaneous fission only produces neutrons and gammas, according to empirical spectral models (the neutrons use Mannhart’s spectrum). The fission fragments are not produced.

1 Like

Thank you! I’ve just tried the 10.6 GEANT4 release and it seems to work fine!


Seems this thread is resolve - it will be closed.