Der Zerfall der Cäsiumisotope Cs¹²⁹ und Cs¹³⁰

Abstract

Cs¹²⁹(T_1/2=32 h) and Cs¹³⁰(T_1/2=30 min) were produced by J¹²⁷(α,2n)Cs¹²⁹and J¹²⁷(α,n)Cs¹³⁰reactions, respectively. The γ-ray-spectra from the decays of Cs¹²⁹ and Cs¹³⁰ have been investigated using Li-drifted Ge-counters and scintillation spectrometers. In the decay of Cs¹²⁹15 γ-rays have been observed having the following energies and relative intensities: 95 keV (1.6), 177 keV (1.1), 267 keV (1.7), 278 keV (4.8), 317 keV (7.6), 371 keV (100), 410 keV (69), 511 keV (≦ 0.1), 548 keV (10.5), 587 keV (1.7), 623 keV (0.12), 660 keV (0.07), 864 keV (0.09), 907 keV (0.67) and 948 keV (0.2). The electron capture branching ratios to the ground state and excited states of Xe¹²⁹were determined; logft values for the various decay branches were derived from these ratios. In the decay of Cs¹³⁰twoγ-transitions with the following energies and intensities relative to the β⁺ emission have been found: 535 keV (11) and 585 keV (1.3). A new level at 1122 keV in Xe¹³⁰is proposed.