【摘要】 从理论上研究了方解石中3 6Cl的 5种起源 :(1)近地表Ca散裂和散裂成因的中子捕获 ;(2 )由Ca产生的负 μ介子捕获 ;(3)负 μ介子捕获以后的中子发射 ;(4 )由快 μ介子引起的光致蜕变反应产生的中子 ;(5 )由U裂变和 (α ,n)反应产生的中子 .论述了3 6Cl在灰岩深度剖面上的 4个分布特征 :(1) 3 6Cl浓度随深度增加而减少 ;(2 )深度能够自然地区分由不同生成反应形成的3 6Cl贡献 ;(3)为了把测量的3 6Cl浓度与Ca的 μ介子捕获及在3 5Cl上 μ介子产生的中子捕获区别开来 ,样品必须具有一定N(Ca) /N(Cl)比值的范围 ;(4 )甚至在最干旱条件下 ,灰岩的侵蚀也是不可避免的 ,并且在稳定状态下起重要作用 .详细描述了3 6Cl的采样方法和AMS分析技术 .研究了测定灰岩侵蚀速率的数学模型 ,并且对一些灰岩表面侵蚀速率作了评价 .更多还原

【Abstract】 Five origins of 36 Cl in calcite were studied theoretically: (1) near surface production by Ca spallation and spallogenic neutron capture, (2) negative muon capture by calcium, (3) neutron emission following negative muon capture, (4) neutrons from photodisintegration reactions initiated by fast muons, (5) neutron from uranium fission and ( α,n ) reactions. Four characteristics of 36 Cl distribution for deep profile in limestone have been discussed: (1) 36 Cl concentration is reduced with depth, (2) depth naturally separates 36 Cl contributions from the various production reactions, (3) in order to partition measured 36 Cl concentrations into contributions from muon capture on Ca and capture of muon produced neutrons on 35 Cl, the sample set must possess a range of Ca/Cl ratios, (4) limestone erosion is inevitable under even the most arid conditions and plays a significant role in determining steady state concentrations. Sampling method of 36 Cl and AMS analytical technique are described in detail. Mathematical model of determining erosion rate in limestone is studied and some surface erosion rate of limestone are evaluated.更多还原