Octupole instability and E1 transitions in222Ra and in the neighbouring even isotopes of radium
作者： E Ruchowska , J Zylicz , C F Liang , P Paris , C Briancon
DOI: 10.1088/0954-3899/18/1/011
关键词: Isotopes of francium 、 Thorium 、 Radium 、 Beta decay 、 Excited state 、 Physics 、 Atomic physics 、 Instability 、 Isotope 、 Isotopes of radium 、 Nuclear physics 、 Nuclear and High Energy Physics
摘要: Isotopes of francium have been produced via a spallation reaction thorium carbide and separated in the ISOCELE facility. The very weak beta branch (0.35%) 220Fr decay 222Fr leading to levels 220Ra 222Ra, respectively, studied by means gamma -ray singles -gated - coincidence measurements. A strong evidence has obtained for 1- state at 412.9 keV 15 new added eight excited states known previously 222Ra. 3- 2+ E1 transition latter nucleus found be remarkably enhanced compared with analogous transitions heavier radium isotopes. This enhancement together low energy reflects octupole instability essentially higher suggests that already lies border region. In contradiction experimental indications theory places inside this For 222Ra it predicts Q1 value not far from authors' result but fails reproduce Q1, changes 224,226,228Ra nuclei.
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