加速器质谱测量岩石样品中<sup>41</sup>Ca的初步研

加速器质谱测量岩石样品中⁴¹Ca的初步研

摘要: ⁴¹Ca在核天体物理及地质年代学方面可能具有较高的应用价值。为测量天然岩石样品中⁴¹Ca的本底水平，探讨了⁴¹Ca-AMS测量中岩石样品的CaF₂制备，提出了二次氟化的制备方法。在此基础上，通过对导电介质与靶锥的改进，设计了一种提高CaF^-₃束流引出强度的方案。该方案可有效提高CaF^-₃束流引出强度。实验结果表明，天然岩石样品中⁴¹Ca/⁴⁰Ca（⁴¹Ca、⁴⁰Ca原子个数比）的本底水平低于8×10^-14。

Abstract: Perhaps the value of ⁴¹Ca applications in nuclear astrophysics and geochronology is high. The CaF₂ preparation of rock samples was investigated to measure the background level of ⁴¹Ca in the natural rock samples by AMS. A preparation method of secondary fluorination was proposed by some physical and chemical processes. On this basis, a program to improve CaF^-₃ beam intensity was designed by improving conductive medium and target cone. This sample preparation program can effectively improve the beam intensity of CaF^-₃. The experimental results show that with these settings the ⁴¹Ca/⁴⁰Ca background level of rock samples is less than 8×10^-14.