Development of a surface-ionization type ion-source at the JAEA-ISOL set-up for a measurement of the first ionization potential of Lr (Z=103)

Sato, Tetsuya   ; Sonoda, Nozomi; Kaneya, Yusuke*; Asai, Masato  ; Tsukada, Kazuaki  ; Toyoshima, Atsushi; Oe, Kazuhiro; Miyashita, Sunao; Osa, Akihiko  ; Ichikawa, Shinichi; Schdel, M.; Nagame, Yuichiro ; Stora, T.*; Kratz, J. V.

In order to determine the first ionization potential of lawrencium (Lr, Z=103), we have developed an appropriate surface-ionization type ion source as a part of the JAEA-ISOL setup, which is coupled to a He/CdI gas-jet transport system. The new ion source is an improved version based on our previously used ion source, which already had a good ionization efficiencies for lanthanide. To achieve higher ionization efficiencies of low volatility elements like Lr, an additional filament was newly installed. We report, here, on the development and performance of our new gas-jet coupled surface-ionization ion source, and on the first successful ionization and mass separation of 27-s Lr produced in the Cf + B reaction.