Does radioactive decay exhibit stimulated emission?

[neanderthalphysics]

TL;DR Summary

Electron energy levels exhibit stimulated emission. Why not nuclear energy levels?

If you have a lump of the same species of radioactive isotopes, why can't the photons emitted from the radioactive decay of one nucleus cause spontaneous emission from other atoms?
I presume it doesn't, because if it did, there would be a geometric effect of radioactive decay, which is not observed.

 

[trurle]

Stimulated gamma emission in nuclear decay do exist but is extremely exotic due small absorbtion cross-sections. Considered most promising Ta-180m was demonstrated to have stimulated gamma emission in laboratory, but the gain is just 0.03 of necessary to make a gamma-laser.