The applicability of the photofission reaction ratio (PFRR) method to identify high-enriched uranium is studied by switching the photon source from the Gaussian spectrum to a bremsstrahlung spectrum. The combination of 6 and 11 MeV Gaussian photon energy was used in previous study for applying PFRR method because the photofission cross sections between ²³⁵U and ²³⁸U at these two energies differ significantly. A parametric study was conducted with the incident electron energy 7.0 MeV and the result showed that these electrons generate similar photofission reactions as that of 6.0 MeV Gaussian photons, while 13.5 MeV electrons is found to give even better results for PFRR considering the measurement noise contributed by multiple neutron emission, (γ, 2n) reaction. Bremsstrahlung photons were injected into a 1 mm thick uranium metal target with varying uranium enrichment. The PFRR increases linearly with uranium enrichment, and is found to provide a higher sensitivity than the Gaussian photons owing to higher total photofission reactions.

通过将光子源从高斯光谱切换到a致辐射光谱，研究了光裂变反应比（PFRR）方法对鉴定高浓铀的适用性。以前的研究中使用6 MeV和11 MeV高斯光子能量的组合来应用PFRR方法，因为光裂变截面在²³⁵ U和²³⁸之间在这两种能量下的U明显不同。对入射电子能量为7.0 MeV进行了参数研究，结果表明这些电子产生的裂变反应与6.0 MeV高斯光子相似，而考虑到由测量噪声引起的13.5 MeV电子，PFRR的结果更好。多重中子发射（γ，2n）反应。将ms致辐射光子注入具有不同铀浓缩度的1 mm厚的铀金属靶中。PFRR随着铀的富集而线性增加，并且由于更高的总光裂变反应而被发现比高斯光子具有更高的灵敏度。