The Disintegration ofNa24andP32

The disintegration of ${\mathrm{Na}}^{24}$ and ${\mathrm{P}}^{32}$ has been studied by means of a $\beta$-spectrometer of the lens type. The $\gamma$-radiation of ${\mathrm{Na}}^{24}$ consists of only two $\gamma$-lines incascade, the energies of which have been determined as 1.380 and 2.758 Mev. $E{\beta }_{max}$ for ${\mathrm{Na}}^{24}$ is 1.390 Mev and for ${\mathrm{P}}^{32}$ 1.712 Mev. In order to obtain $\beta$-spectra without secondary electrons, exceedingly thin foils and very small quantities of active materials have been used. With these precautions it appears that the electron distributions follow the allowed form of $\beta$-spectra. However, ${\mathrm{Na}}^{24}$ and ${\mathrm{P}}^{32}$ are empirically forbidden spectra of the first and second order, respectively. According to the theory of forbidden spectra developed by Uhlenbeck and Konopinski, the distribution for at least ${\mathrm{P}}^{32}$ would differ from the allowed one.