A coupling between the nuclear and electronic energy losses occur in the nuclear fuel (UO₂) during in-reactor operations. However, the underlying mechanisms involved are still to be investigated. In this work, synergistic effects of nuclear and electronic energy losses have been investigated by irradiating crystals with single (900 keV I ions or 27 MeV Fe ions) and dual (900 keV I ions and 27 MeV Fe ions, simultaneously) ion beams at the JANNUS-Saclay facility. The damage build-up kinetic was in situ characterized by Raman spectroscopy. The microstructure evolution was determined by transmission electron microscopy (TEM) observations and by X-ray diffraction (XRD) analysis. Results show that both crystalline disorder and strain level are lower under dual-beam compared to the single-beam ion irradiations. Indeed, the dual-beam irradiation induces a transition from the formation of dislocation loops to dislocation lines. This result can be explained, in the framework of the thermal spike model, by a local increase of the temperature along the high-energy ion path. This temperature increase likely induces an enhanced defect migration leading to defect rearrangement.

反应堆内操作期间，核燃料损失（UO ₂）发生核能和电子能量损失之间的耦合。但是，所涉及的潜在机制仍有待研究。在这项工作中，已经通过向单晶（900 keV I离子或27 MeV Fe离子）和双晶（900 keV I离子和27 MeV Fe离子，同时）离子束照射晶体，研究了核能和电子能量损失的协同效应。 JANNUS-Saclay设施。损伤累积动力学是原位的以拉曼光谱为特征。通过透射电子显微镜（TEM）观察和X射线衍射（XRD）分析确定了微观结构的演变。结果表明，与单束离子辐照相比，双束辐照下的晶体紊乱和应变水平均较低。实际上，双束辐照引起从位错环的形成到位错线的转变。该结果可以在热尖峰模型的框架内通过沿高能离子路径的温度局部升高来解释。温度升高可能导致缺陷迁移增强，导致缺陷重排。