A new isotope andα-lines in the Th-Np region and their production cross-sections

Abstract

In the fusion reactions of^20,22Ne with²⁰⁵Tl,²⁰⁸Pb, and²⁰⁹Bi the absolute production cross-sections of the²²⁷Np,^222–224Pa,^222–224Th, and²²¹Ac isotopes were measured and the products of the xn evaporation channels and theirα-decay properties were investigated. The identified isotope is²²⁷Np (7680±10 keV). A newα-line structure of²²⁴Pa was established (7460±10 keV (25±3 %) and 7555±10 keV (75±3 %)). Fourα-lines of²²³Th were identified (7290±10 keV (41±5 %), 7320±10 keV (29±5 %), 7350 ± 15 keV (20±5 %), and 7390±15 keV (10±4 %)). The half life of²¹⁷Fr was measured to be 16±2 μs and that of²²⁰Ra was found to be 17 ±2 ms.