TEM Characterization of Uranium Fission - Fragment Damage in Natural Apatite and Zircon

天然磷灰石和锆石中铀裂变碎片损伤的 TEM 表征

• 批准号: 9112379
• 负责人: Maryellen Cameron
• 金额: --
• 依托单位: Miami University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-15 至 1993-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9112379&HistoricalAwards=false
• 关键词: TEM; Characterization; Uranium; Fission; Fragment

The transmission electron microscopy will be used to elucidate the atomic-scale damage produced in naturally-occurring apatite an zircon by induced fission of substituent U-235. Objectives of the research are to characterize the general structure of unannealed latent fission tracks in apatite, to obtain lattice-fringe images within and adjacent to fission tracks in apatite, and to characterize the general structure of unannealed latent tracks in zircon. Crystals to be examined in this study are zircon and Durango apatite (a near end-member fluorapatite). Observations on the apatite will require a cold-stage maintained at liquid nitrogen temperatures in order to minimize beam damage to the crystals and prevent thermal annealing of the fission tracks. Observations on both minerals will be made under varying experimental conditions (e.g., different electron microscopes using various detector systems and collection methods, and different voltages, modes of imaging, crystal orientations. etc.).

透射电子显微镜将被用来阐明原子尺度的损伤产生的天然磷灰石和锆石的诱导裂变取代U-235。研究的目的是表征磷灰石中未退火的潜在裂变径迹的一般结构，获得磷灰石中裂变径迹内和附近的晶格条纹图像，并表征锆石中未退火的潜在径迹的一般结构。在这项研究中要检查的晶体是锆石和杜兰戈磷灰石（近端元氟磷灰石）。对磷灰石的观测将需要一个保持在液氮温度下的冷台，以尽量减少对晶体的光束损伤，并防止裂变径迹的热退火。对这两种矿物的观察将在不同的实验条件下进行（例如，不同的电子显微镜使用不同的检测器系统和收集方法，以及不同的电压、成像模式、晶体取向。等）。