EPJ A Highlight - First measurement of 60Ge β-decay

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Published on 22 April 2016

⁶⁰Ge, with its 28 neutrons and 32 protons, is an extremely exotic nucleus, discovered about 10 years ago when only three ions were produced. Its decay properties were measured for the first time in this work. In this experiment, performed at the National Superconducting Cyclotron Laboratory (MSU, USA), the

⁶⁰Ge ions were produced in ⁷⁸Kr beam fragmentation reactions and separated from the other reaction products in the A1900 separator. The ions were detected in the active volume of the gaseous time-projection chamber with optical readout (OTPC), where they later decayed. This detector allows exotic decay modes to be identified, even with very small statistics present. The decay of about 20

⁶⁰Ge ions was observed by β-delayed proton emission yielding a branching ratio of ~100% and a half-life of 20⁺⁷_-5 ms. This value agrees well with theoretical predictions.