I learned that Sodium22 atoms decay to Neon 22 by ($\beta$+) (positron) emission. Also some other radioactive elements isotopes can undergo positron emission or electron absorption with a similar result.

Would it be possible to strip all the electrons away from a Ne22 nucleus, then hit it with a gamma-ray photon or maybe an x-ray photon causing it to emit an electron and become Na22?

Ne22($\gamma$) = Na22($\beta$)

In other words, can electric charge influence radioactivity and can a gamma photon turn a stable isotope into an unstable one?

By X-rays, I mean slightly longer wavelength than gamma. I believe that if an X-ray hit a non-ionized Ne22 atom it would simply knock off one or more electrons from the atom but what if an X-ray hit a Ne22 nucleus with all it's electrons already stripped away? With no more electrons to knock off, could it cause one of the neutrons to emit an electron and the nucleus become Na22?

  • $\begingroup$ Well, gamma levels of nuclei and known gamma-induced nuclear reactions can be found at nndc.bnl.gov/ensdf or mirror sites. $\endgroup$
    – Jon Custer
    Commented Apr 2, 2021 at 19:04

2 Answers 2


The beta decay is more precisely written as $$ n \to p^{+} + e^{-} + \bar\nu_e$$ which means a neutron from the nucleus decays into a proton, an electron, and an electron anti-neutrino. In this equation the electric charge is conserved, as well as the lepton number. Hence, you definitely have to change your equation.

Usually, $^{22}Ne$ is considered to be stable. This is to say that it is energetically favourable for the nucleus to keep this configuration. However, I cannot think of a reason why the decay rate should be exactly zero, if we feed enough energy to the nucleus. Of course the energy must be huge, because the "natural" energy scale of the nucleus are several MeV. Gamma rays possess these energies, but stripping the electrons will probably yield only energies in the keV range, see Wiki. Thus, stripping the electrons contributes only a tiny amount of the "natural energy scale" of the nucleus.

  • $\begingroup$ If I read the wiki correctly it looks like 1.36 KeV. There may be a flaw in my reasoning here but I was thinking that the positive electric charge could somehow help "draw out" an electron from inside a neutron (make the probability of decay higher) if the nucleus was hit with enough energy for the mass-energy equivalent of an electron. $\endgroup$ Commented Apr 2, 2021 at 22:09
  • $\begingroup$ If you think in terms of classical EM interaction the electrons are just too far away: While the Bohr radius is 0.5nm the nucleus has a size of ~ fm. Thus, we have a gap of four orders of magnitude. However, beta decay is due to the weak interaction. We can not simply use standard physics inside the nucleus. While I can imagine that additional energy opens other some channels, I don't believe that weak interaction requires an activation energy. However, this is far beyond my field. So you should check that. $\endgroup$
    – Semoi
    Commented Apr 3, 2021 at 9:06

To simply put it, yes. This is known as photodisintegration. The absorption of gamma rays can cause the emission of protons, neutrons, alpha particles, and it can even cause nuclear fission (although causing nuclear fission with gamma rays is known as photofission, not photodisintegration).

Fun fact: The neutron was discovered by photodisintegrating deuterium!


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