The First successful determination of the first ionization potential of lawrencium (Lr, )

Sato, Tetsuya   ; Asai, Masato  ; Sato, Nozomi; Kaneya, Yusuke; Toyoshima, Atsushi; Miyashita, Sunao*; Oe, Kazuhiro*; Osa, Akihiko  ; Ichikawa, Shinichi; Nagame, Yuichiro ; Schdel, M.; Renisch, D.*; Stora, T.*; Dllmann, Ch. E.*; Kratz, J. V.

The first ionization potential of the heaviest actinide elements have not been measured until today owing to short half-lives and low production rate of the isotopes. Based on the surface ionization technique, we performed a measurement of the ionization potential of the heaviest actinide element, lawrencium (Lr, ), by using a newly developed surface ion-source installed to the JAEA-ISOL (Isotope Separator On-Line) at the JAEA tandem accelerator facility. We report on an evaluation of the IP value of Lr based on comparison of ionization behavior of short-lived lanthanide isotopes and Lr on Ta surface at several temperature in the ion-source.