^(236)U及其加速器质谱(AMS)测量

^(236)U and Its Measurement with Accelerator Mass Spectrometry

236U是一种长寿命放射性核素,其半衰期为T1/2=2.342(3)×107a,在自然界的含量极微,天然铀中236U/238U的原子比约为～10-14。目前,对于236U及其测量的研究报道较少。首先介绍了236U的产生,并对地球中236U的总量进行了估算。概述了236U测定在亿年级中子注量率积分评估、核环境和核活动监测,以及地质学等领域中的重要应用。最后,对国内外加速器质谱(AMS)测量236U的状况进行了综述,报道了中国原子能科学研究院AMS小组通过对同位素干扰鉴别的多方面研究,初步建立了236U-AMS测量方法。

236U is a long-lived radionuclide with half-life of 2.342（3）×107 a.The ratio of 236U/238U is about 10-14 in the natural Uranium.The origin and production of 236U in globe are introduced and estimated in this paper,respectively.The major applicationsion of 236U as a 100-million year neutron flux integrator,as a ＂fingerprint＂ for monitoring nuclear environment and nuclear activity,and as a tracer in geological studies are briefly summarized.The accelerator mass spectrometry（AMS） measurement of 236U in the world and the research on HI-13 tandem accelerator at China Institute of Atomic Energy（CIAE） is also mentioned in this paper.