Beta-Spectra ofCo56,Co57, andCo58

For ${\mathrm{Co}}^{58}$ the 472-kev positron spectrum has been confirmed and the $K$ conversion coefficient of the 805-kev gamma-ray has been found to be (2.9±0.2)×${10}^{-4\mathrm{}}$. For ${\mathrm{Co}}^{57}$ the positron spectrum has been found to have an end-point energy of 320±15 kev. Conversion electrons of 119-kev and 133-kev gamma-rays and a very soft (${\mathrm{Fe}}^{57}$ have been observed. The $\frac{K}{L}$ ratios of the 119-kev and the 133-kev gamma-rays have been estimated to be about 6.3 and 5.2, respectively. For ${\mathrm{Co}}^{56}$ two positron spectra have been observed, one having an end-point energy of 1.53±0.02 Mev, the other having an end-point energy of 995±25 kev.