Abstract
The γ radiation following the decay of Ba144 to La144 was measured with a variety of detectors in experiments where γ-ray singles, time dependent γ-ray spectra, γγt coincidence, and γγt angular correlation data were collected. The Ba144 activity was produced by on-line mass separation from the products of the U235(n,f) reaction. The half-life of Ba144 was determined to be 11.5±0.2 s. A level scheme for odd-odd La144 was deduced from coincidence information in which 91 γ rays were placed among 26 levels. Internal conversion and angular correlation measurements yielded spin-parity assignments for several levels. Several features of the level scheme are discussed including the β decay to low-lying levels and the possible core-coupled structure of the 1+ levels. RADIOACTIVITY Ba144 [from U235(nth,f)], measured t12, Eγ, Iγ, αK, γγ coincidence, γγ(θ) angular correlation; HPGe, Ge(Li), and LEPS detectors; La144 deduced levels, Jπ, Iβ, δ, and logft. Mass-separated Ba144 activity. © 1982 The American Physical Society.