Topic summary

Beta emission

Extracted from the Wikipedia article Beta decay.

Beta emission spectrum

Beta decay can be considered as a perturbation as described in quantum mechanics, and thus Fermi's Golden Rule can be applied. This leads to an expression for the kinetic energy spectrum $N (T)$ of emitted betas as follows: $N(T)=C_{L}(T)F(Z,T)pE(Q-T)^{2}$ where $T$ is the kinetic energy, $C L$ is a shape function that depends on the forbiddenness of the decay (it is constant for allowed decays), $F (Z, T)$ is the Fermi Function (see below) with Z the charge of the final-state nucleus, $E = T + mc$ is the total energy, $p={\sqrt {(E/c)^{2}-(mc)^{2}}}$ is the momentum, and $Q$ is the Q value of the decay. The kinetic energy of the emitted neutrino is given approximately by $Q$ minus the kinetic energy of the beta.

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