A Beta Decay Rates Changing by Ionization?

[Aakash Sunkari]

I recently read about a beta decay isotope (Rhenium-187),whose half life was changed from 42 X 10⁹ years to 33 years, just by stripping the nucleus of all it's electrons. Why does this allow for a faster decay, and does this apply to all beta decay nuclei, or just Rhenium 187?

 

[mathman]

Could you give the reference?

 

[Aakash Sunkari]

Sure. The paper written about it is here: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.77.5190

 

[mfb]

Technically all beta- decay rates are influenced by this, but for most nuclei the influence is completely negligible. Re-187 with its extremely small decay energy is a notable exception. While it can decay normally this is a very rare process. If you remove electrons it can do a bound-state decay where the produced electron stays in the atom, this process is much more common then.
Dysprosium-163 has this even more pronounced: As neutral atom it is stable, but if you remove its electrons it becomes radioactive.

Beryllium-7 is the opposite: It can decay only via electron capture. Remove all the electrons and it becomes stable. It has not enough energy for a beta+ decay.

These are very exotic examples.