Alpha & Proton Decay: Explaining Unequal Rates

[majid313mirzae]

All nuclei with A > 210 are alpha emitters, yet very few emit protons spontaneously.
Yet both decays lower the Coulomb energy of the nucleus. Why is
proton decay not more common?

 

[Vanadium 50]

Look at the binding energy curve.

 

[mathman]

All nuclei with A > 210 are alpha emitters, yet very few emit protons spontaneously.
Yet both decays lower the Coulomb energy of the nucleus. Why is
proton decay not more common?

Some of these nuclei undergo beta decay, not alpha.

 

[lpetrich]

The binding energy of alpha particles means more energy available to make the decay happen -- it happens by quantum-mechanical tunneling.

I could dig up the alpha decay rate if anyone is interested - it also works for protons.