Performance of a total absorption clover detector for measurements of neutron-rich nuclei far from the -stability line

Hayashi, Hiroaki*; Shibata, Michihiro*; Asai, Masato  ; Osa, Akihiko  ; Sato, Tetsuya   ; Koizumi, Mitsuo ; Kimura, Atsushi   ; Oshima, Masumi*

To measure -decay energy of short-lived fission products with good accuracy and high efficiency, we have developed a new total absorption clover detector and demonstrated its performance. Using a large-volume clover-type Ge detector having a through-hole in its center, we could measure total absorption spectra of + rays with extremely high efficiency and high energy resolution, and could determine values with 30 keV accuracy. Using this detector, we have determined the values of Eu and Gd for the first time, and of Eu and Gd with better accuracies. In addition, we have observed a new isomeric state in Gd, and determined its half-life and excitation energy.