Observation of New Nuclide ²³⁹Pa

A new nuclide ²³⁹Pa was produced by 50MeV/u ^l8O bombardment of natural uranium via multi-nucleon transfer reactions (²³⁸U-lp+2n). Protactinium was chemically separated from the uranium target and other produced elements. Then in that chemical fraction the growth and decay of ²³⁹U gamma rays were observed, identifying the ²³⁹U parent as ²³⁹Pa. Subsequent to ²³⁹Pa β^- decay, with a half-life of 106±30min, gamma rays of 522.0, 562.0, 638.5 and 681.0keV were also observed.