-ray spectroscopy of the heaviest nuclei at the JAEA-Tokai Tandem laboratory, using Cf and Es targets

Orlandi, R.; 牧井 宏之; 西尾 勝久; 廣瀬 健太郎; 塚田 和明; 浅井 雅人; 永目 諭一郎; 佐藤 哲也; 豊嶋 厚史; Vermeulen, M. J.; et al.

no journal, , 

The spectroscopy of heavy nuclei near the =152 and =162 deformed shell gaps provides precious information to improve current predictions of super-heavy elements in the Island of Stability. Due to deformation, in fact, substates of spherical orbits in the Island of Stability can be found in the Fermi level in these lighter nuclei. At the JAEA-Tokai Tandem accelerator, the first in-beam -ray spectroscopy of Fm (=100, =162) was attempted. Fm was produced via the multi-nucleon transfer reaction Cf (C,Be) reaction. The particle-gamma detection setup comprised an array of Si detectors to identify the reaction ejectiles, and a mixed array of four Germanium and four LaBr(Ce) detectors, with an absolute photopeak efficiency of nearly 30%. The X-rays of fermium and candidate transitions for the ground state rotational band of Fm were observed. The implications of this test measurement and future projects involving a Es target are presented.