激光烧蚀铀材料生成铀微粒的形态学研究

本文以激光器作光源，利用激光的高温烧蚀特性，以激光束烧蚀金属铀和二氧化铀材料，模拟高温条件下形成铀微粒的过程，用扫描电子显微镜和透射电子显微镜对铀材料及产生的含铀微粒的形态学特点进行了表征。实验表明，在激光束的轰击下，两种靶材料均出现熔化现象，铀金属表面呈现明显波纹状结构，二氧化铀的表面轰击边缘处呈现趋球状物堆积。生成的铀氧化物微粒为μm级形态不规则微粒及1 μm左右的球形微粒，说明铀在高温过程中产生球形微粒。对比研究了来自高温爆炸过程的金属银微粒，进一步验证了高温高压过程会产生球形微粒。结果表明，密实的铀氧化物微球是铀材料参与高温化学过程的结果，与低温过程中的剥蚀作用有明显的差别，是高温化学过程的特征，这为高温高压环境中的微粒分析提供了参考依据。

Morphology Characterization of Uranium Particles From Laser Ablated Uranium Material

Metallic uranium and uranium dioxide material were ablated by laser beam in order to simulate the process of forming the uranium particles in pyrochemical process. The morphology characteristic of uranium particles and the surface of uranium material were represented by SEM and TEM. Those two kinds of materials are melted，the surface of metal uranium presents a series wavelike segments and the surface of dioxide uranium presents pellets aggregation under the bombardment of laser beam. The irregular micron-sized particles and about 1 μm spherical particles occurred in ambient environment. Silver aerosol particles produced by explosion also were characterized as spherical particles. The results show that the regular uranium oxide spheres with high density characteristic pyrochemical process are quite different from particles with low temperature denudation. They are characteristic of pyrochemical process based on particle morphology. These results will provide references for uranium particles research related to high temperature and high pressure process.