New (U-Th)/He dating systems and ages in Japan Atomic Energy Agency

Yamada, Kunimi; Hanamuro, Takahiro  ; Tagami, Takahiro*; Takagi, Hideo*; Shimada, Koji   ; Umeda, Koji; Iwano, Hideki*; Danhara, Toru*

Japan Atomic Energy Agency have jointly set up the system of the (U-Th)/He dating in cooperation with Kyoto University and National Institute for Earth Sciences and Disaster Prevention. Through this two years, helium extraction machine using an electronically-cooled diode laser, micro crusible system using XRF bead sampler and uranium and thorium quantification procedure without artificial spikes are developed. Now we produce new ages of some age known samples. At the present stage, the accuracy and precision are roughly 20 and 10%, respectively, using the age standard zircon from the Fish Canyon Tuff (FC3). In the presentation, we will introduce our systems and the ages detailedly.