Internal Bremsstrahlung fromP32

The spectral distribution of the internal bremsstrahlung associated with the beta decay of ${\mathrm{P}}^{32}$ has been measured with a NaI scintillation spectrometer from 80 to 900 kev. The shape of the experimental spectrum is compared with the theoretical distribution, corrected for detector response, for three different beta interactions: (1) allowed; (2) first-forbidden; scalar; (3) first-forbidden; tensor; $\Delta J=2\mathrm{}$, yes. The results show that of these interactions, only the allowed case gives a theoretical curve within the estimated error (10 percent) of the experimental points over the entire range of energy.