核反应截面替代测量方法介绍
Introduction of Surrogate Approach for Determining Nuclear Reaction Cross Sections
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摘要: 核反应截面替代测量方法是一种间接测定核反应截面的方法， 这种方法对于测定不稳定核的反应截面具有重要的意义。 详细介绍了替代方法的理论基础、 影响其精确性的重要因素， 以及基于该方法的3种变型方法： 外替代比率方法（ESRM）、 内替代比率方法（ISRM）和混合替代比率方法（HSRM）。 阐明了每一种方法的基本原理， 给出了相关的实验验证， 并且对每一种方法的优缺点进行了分析。发现在每一种方法中， 所求反应与替代反应之间的自旋宇称不匹配始终是不可消除的一个影响因素。 但是经过实验验证， 替代方法（包括3种变型方法）也可以达到较高的精确度， 因而在不能够直接测定核反应截面的情况下， 该方法不失为一种很好的间接测量方法。The surrogate nuclear reaction approach plays an important role in the determination of nuclear reaction cross sections that are difficult to be measured directly. In this paper， we investigate its basis， factors affecting its accuracy， and its three variants: the external surrogate ratio method (ESRM)， the internal surrogate ratio method (ISRM) and the hybrid surrogate ratio method (HSRM). Each method was described， and their applications or experimental tests were given， from which we could see their respective advantages and disadvantages. And it is found that the spinparity mismatch， or the (weak) WeisskopfEwing limit equivalently， is an inherent limitation of the approach. It is also seen that the surrogate approach can reach a high accuracy， so it is a good indirect approach when the nuclear reaction cross sections are unavailable to be measured directly.Abstract: The surrogate nuclear reaction approach plays an important role in the determination of nuclear reaction cross sections that are difficult to be measured directly. In this paper， we investigate its basis， factors affecting its accuracy， and its three variants: the external surrogate ratio method (ESRM)， the internal surrogate ratio method (ISRM) and the hybrid surrogate ratio method (HSRM). Each method was described， and their applications or experimental tests were given， from which we could see their respective advantages and disadvantages. And it is found that the spinparity mismatch， or the (weak) WeisskopfEwing limit equivalently， is an inherent limitation of the approach. It is also seen that the surrogate approach can reach a high accuracy， so it is a good indirect approach when the nuclear reaction cross sections are unavailable to be measured directly.
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