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Alpha Decay via Gamow Tunneling

What you are seeing: the alpha-decay process. An alpha wavefunction oscillates in the nuclear well, decays exponentially across the shaded classically forbidden Coulomb barrier (WKB suppression set by the Gamow exponent), and leaks a small transmitted wave. The nucleus emits alpha particles at a cadence mapped from the Geiger-Nuttall half-life, so a high-$Q$ nuclide streams alphas through a narrow barrier while a low-$Q$ one is nearly quiescent behind a wide one. The compact strip keeps the $\log_{10} T_{1/2}$ versus $Q^{-1/2}$ line with the live $(Z, Q)$ marker.

Figure 1. Geiger-Nuttall: log10(T1/2)\log_{10}(T_{1/2}) vs Q1/2Q^{-1/2}.
Z (daughter)90
Q (MeV)4.50

WHAT TO TRY

  • Raise the decay energy Q: the alpha tunnels through a thinner, lower barrier and the half-life plummets, the steep Geiger-Nuttall law spanning twenty-odd orders of magnitude in lifetime.
  • Increase the daughter charge Z: the Coulomb barrier rises and widens, suppressing the tunnelling exponentially, which is why high-Z nuclei decay so slowly.
  • Watch the wavefunction leak across the shaded forbidden region: the alpha rattles the barrier billions of times a second, and only the tiny transmitted amplitude sets the rate.