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arXiv 1902.05620physics.ins-detphysics.app-ph
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不同截面中子辐照损伤的计算与验证

Calculation and verification of neutron irradiation damage with differential cross sections

Shengli Chen, David Bernard, Pierre Tamagno, Jean Tommasi, Stephane Bourganel, Gilles Noguere, Cyrille De Saint Jean

备注：
arXiv admin note: text overlap with arXiv:1902.04889
发表信息：
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Volume 456, 1 October 2019, Pages 120-132
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摘要：

在反应堆应用中，每原子位移（DPA）速率通常用DPA截面计算。本文提出并推荐了在质心坐标系下直接计算能量角分布的方法。提出了改进和验证DPA截面计算的方法：（i）基于Gauss-Legendre-Quadrature-based Piecewise Integration（GLQPI）的积分法，保证被积函数不连续时积分在发射角上的数值收敛性;（ii）验证梯形积分在二次能量上的收敛性;（iii）双微分截面的插值。对于JEFF-3.1.1的56 Fe，当前的发射角数值积分不收敛，而二次能量的直接梯形和能量-角-积分损伤的直接内插是准确的。另一方面，它表明，DPA的截面高估，如果各向同性的角分布假设。然而，DPA截面对高阶勒让德多项式不敏感，因为前者是角度积分量。中子弹性散射的数值计算结果表明，对于裂变堆，2阶勒让德多项式可以给出56 Fe的DPA率，其误差不超过0.5%，而对于聚变堆，需要4阶勒让德多项式。对于中子非弹性散射诱导的DPA，一阶勒让德多项式对于裂变和聚变反应堆都是足够的。

英文摘要：

The Displacement per Atom (DPA) rate is conventionally computed with DPA cross sections in reactor applications. The method of direct calculation with energy-angular distributions given in the Center of Mass (CM) frame is proposed and recommended in the present work. The methods for refining and verifying the calculations of DPA cross sections are proposed: (i) Gauss-Legendre-Quadrature-based Piecewise Integration (GLQPI) for ensuring the numeric convergence of integral over emission angle due to the discontinuity of integrand; (ii) verification of the convergence for trapezoidal integration over the secondary energy; (iii) interpolation of double-differential cross sections. For 56Fe of JEFF-3.1.1, the current numeric integration over emission angle is shown not convergent, whereas the direct trapezoidal over the secondary energy and the direct interpolation of energy-angle-integrated damage are shown accurate. On the other hand, it is shown that the DPA cross sections are overestimated if isotropic angular distributions are assumed. However, the DPA cross section is not sensitive to the high-order Legendre polynomials because the former is an angle-integrated quantity. Numerical results of neutron elastic scattering show that 2 orders of Legendre polynomials can give the DPA rates of 56Fe within 0.5% overestimation for fission reactors, while 4 orders are required for fusion reactors. For neutron inelastic scatterings-induced DPA, the first order Legendre polynomial is sufficient for both fission and fusion reactors.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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