Energies of the Beta- and Gamma-Rays from Antimony

The radiations from antimony bombarded by slow neutrons have been investigated in a large, high resolution, shaped-field magnetic spectrometer. The beta-spectrum of ${\mathrm{Sb}}^{124}$ (60 d.) was measured with a relatively thin source and with a thin window counter. The spectrum is found to be complex. By means of the Fermi theory, it is possible to resolve the distribution into at least five groups having the following end points and intensities: 2.37 Mev, 21 percent; 1.50 Mev, 7 percent; 0.98 Mev, 7 percent; 0.68 Mev, 26 percent; 0.50 Mev, 39 percent. An internal conversion line was detected corresponding to a gamma-ray of 0.121 Mev. Measurements on the Compton and photoelectrons ejected from a thin Pb radiator yield additional gamma-ray energies of 0.608, 0.654, 0.732, 1.708, and 2.04 Mev. Measurements made while the short period activity was still present indicate that a gammaray of 0.568 Mev is associated with the 2.8-day activity of ${\mathrm{Sb}}^{122}$.