Electron Shake-Off Following the Beta Decay ofNe23

A specially designed mass spectrometer is used to analyze the sodium ions that result from the ${\beta }^{-}$ decay of ${\mathrm{Ne}}^{23}$. The percent abundances are as follows: ${\mathrm{Na}}^{1+}$ (79.1), ${\mathrm{Na}}^{2+}$ (17.5), ${\mathrm{Na}}^{3+}$ (2.85), ${\mathrm{Na}}^{4+}$ (0.48), ${\mathrm{Na}}^{5+}$ (0.081), ${\mathrm{Na}}^{6+}$ (0.006), ${\mathrm{Na}}^{7+}$ (<0.002). No evidence is found that recoil energy contributes to the electron shake-off. An attempt is made to derive the charge spectrum from the assumption that electron shake-off is due to the sudden, nonadiabatic change in nuclear charge. Multiple electron shake-off is computed from the product of the probabilities for single electron shake-off. The probabilities for single electron shake-off are semiempirically calculated. In general, the calculated values agree well with the experimental data, though the computations underestimate the abundances of the more highly charged ions.