$\gamma$-ray emission from ${}^{12}\mathrm{C}$ and ${}^{13}\mathrm{C}$ samples irradiated with deuterium-tritium fusion neutrons was experimentally measured at the Omega Laser Facility and at the Ohio University Edwards Accelerator Laboratory. The intent of these measurements was to determine the feasibility of using ${}^{13}\mathrm{C}$-based plastic ablators with embedded ${}^{12}\mathrm{C}$ layers for “dark mix” diagnosis of inertial confinement fusion implosions. Spectrally resolved measurements at Ohio University identified significant 4.44-MeV $\gamma$-ray emission from the ${}^{13}\mathrm{C}(n,2n\gamma ){}^{12}\mathrm{C}$-L1 reaction channel. The recorded 4.44-MeV ${}^{13}\mathrm{C}$ signal was compared against emission from an identically irradiated ${}^{12}\mathrm{C}$ target with known ${}^{12}\mathrm{C}$($n,n^{\prime }\gamma ){}^{12}\mathrm{C}$-L1 cross section, which resulted in an average ${}^{13}\mathrm{C}(n,2n\gamma ){}^{12}\mathrm{C}$-L1 cross section of 117 $\pm$ 17 mb over the incident neutron energy distribution range from 14.4 to 15.8 MeV. Integrated ${}^{13}\mathrm{C}$ $\gamma$-ray signals above 2.9 MeV recorded with the Gas Cherenkov Detector at Omega exceeded MCNP6.1 predictions by a factor of 3. The additional signal was attributed to 4.44-MeV $\gamma \mathrm{s}$ resulting in an inferred ${}^{13}\mathrm{C}(n,2n\gamma ){}^{12}\mathrm{C}$-L1 cross section of $95\pm 11$ mb at 14.1-MeV average incident neutron energy. As a result, the ${}^{13}\mathrm{C}$-based “dark mix” diagnostic concept was deemed infeasible.

中文翻译：

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C13(n,2nγ)C12γ 射线在 14-16 MeV 入射中子能量范围内的产生

$\gamma$-射线发射 ${}^{12}\mathrm{C}$ 和 ${}^{13}\mathrm{C}$用氘-氚聚变中子辐照的样品在 Omega 激光设施和俄亥俄大学爱德华兹加速器实验室进行了实验测量。这些测量的目的是确定使用${}^{13}\mathrm{C}$嵌入式塑料消融器 ${}^{12}\mathrm{C}$惯性约束聚变内爆的“暗混合”诊断层。俄亥俄大学的光谱分辨测量确定了显着的 4.44-MeV$\gamma$- 射线发射 ${}^{13}\mathrm{C}(n,2n\gamma ){}^{12}\mathrm{C}$-L1反应通道。记录的 4.44-MeV${}^{13}\mathrm{C}$ 将信号与来自相同辐照的发射进行比较 ${}^{12}\mathrm{C}$ 已知目标 ${}^{12}\mathrm{C}$($n,n^{\prime }\gamma ){}^{12}\mathrm{C}$-L1 横截面，这导致平均 ${}^{13}\mathrm{C}(n,2n\gamma ){}^{12}\mathrm{C}$-L1 横截面 117 $\pm$17 mb 在入射中子能量分布范围从 14.4 到 15.8 MeV。融合的${}^{13}\mathrm{C}$ $\gamma$欧米茄气体切伦科夫探测器记录的高于 2.9 MeV 的 -射线信号超过 MCNP6.1 预测的 3 倍。额外的信号归因于 4.44-MeV $\gamma \mathrm{秒}$ 导致推断 ${}^{13}\mathrm{C}(n,2n\gamma ){}^{12}\mathrm{C}$-L1 横截面 $95\pm 11$mb 为 14.1-MeV 平均入射中子能量。结果，该${}^{13}\mathrm{C}$基于“暗混合”的诊断概念被认为是不可行的。