R＆D of a ^<129>I Direct Detection System with an Electrostatic Accelerator

在筑波大学12UD串联式静电加速器上成功地建立了超高灵敏度加速器质谱仪系统。一种新发展的分子先导束流方法使我们在12UD加速器上无需任何修改即可实现AMS系统。AMS调到了^&lt；129；i测量值。1)方法97&gt；MoO_2分子导引束法2)样品形式AgI 3)先导材料97&gt；MoO_34)碘离子流~10μA 5)97&gt；MoO_2离子流~10nA6)加速电压9.7 MV 7)先导粒子97&gt；Mo^&lt；9+&gt；-5)灵敏度5×10^；I/^&lt；127&gt；i)准确度~15%人们强烈要求提高准确度，目前正在进行中。虽然现在系统的性能并不完美，但为想要测量^&lt；129；i元素的用户启动了^&lt；129；i-AMS服务。

An ultra high-sensitive accelerator mass spectrometry system, AMS, has been constructed successfully on a 12UD tandem electrostatic accelerator at the University of Tsukuba. A newly developed ^<97>MoO_2 molecular pilot beam method allowed us to realize the AMS system without any modifications in the 12UD accelerator. The AMS is tuned up to ^<129>I measurements. The performances for the ^<129>I AMS are listed up on the followings.1) Method ^<97>MoO_2 molecular pilot beam method2) Sample form AgI 3) Pilot material ^<97>MoO_34) Iodine ion current 〜10μA 5) ^<97>MoO_2 ion current 〜10nA6) Acceleration voltage 9.7MV 7)Pilot particle ^<97>Mo^<9+>8) Sensitivity 5×10^<-13> (^<129>I/^<127>I) 9)Accuracy 〜15%The improvement of the accuracy is strongly requested and it is under going. Though the performance of the system is not perfect now, the ^<129>I-AMS services are started for the users who want to measure the ^<129>I element.