THE DECAY OF Ba133

Abstract

The electron-capture decay of Ba133 and the subsequent de-excitation of Cs133 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 Cs133: 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.