对质子滴线核^（19）Na的β延迟质子衰变的首次观察

First Observation of β-delayed Proton Decay of the Proton Drip Line Nuclide ￣(19)Na

由（２０）Ｎｅ（Ｐ，２ｎ）（１９）Ｎａ反应，对质子滴线核（１９）Ｎａ进行了研究，实验在中国科学院高能物理研究所质子直线加速器上进行，首次观察到了（１９）Ｎａ的β延迟质子衰变，测定其质子能量为１．１０±０．０８ＭｅＶ，半衰期为４７±２０ｍｓ，它相应于（１９）Ｎａ基态到（１９）Ｎｅ的７．６２ＭｅＶ、Ｔ＝３／２同位旋相似态的超允许β跃迁和由此态到（１８）Ｆ基态的级联质子衰变．

Na, a nuclide on proton drip line, was studied by (20)Ne(p,2n) (19)Na reaction.Experiment was performed on the proton linear accelerator at institute of High Energy Physics, The Chinese Academy of Sciences. The new decay mode of β-delayed proton decay was observed for the first time. The half-life of (19)Na was determined to be 47±20ms and its proton energy was measured to be 1.10±0.08MeV which is corresponding to super-allowed beta transition of (19)Na to excited state of 7.62MeV,the isospin analog state with T=3/2 in (19)Ne, and subsquent proton emission to the ground state of 18F.