THE DECAY OF Ba¹³³

Abstract

The electron-capture decay of Ba 133 and the subsequent de-excitation of Cs 133 have been investigated with magnetic and scintillation spectrometers. The measured conversion coefficients and transition intensities lead to the following spin assignments for the states of Cs 133 : ground, 7/2+; 81 kev, 5/2+; 161 kev, 5/2 +; 383 kev, 3/2+; and 437 kev, 1/2+. The multipolarities of the connecting transitions are: 54 kev (M1), 80 kev (M1), 81 kev (M1), 161 kev (M1+E2), 276 kev (E2), 302 kev (M1+E2), 356 kev (E2), and 383 kev (E2). The limits of experimental error in the measured conversion coefficients do not exclude the possibility that the 437-kev level is 3/2+ and that both the 276- and 356-kev transitions are M1 + E2 admixtures.