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Radiation-induced Defects in Nonradioactive Natural Minerals: Mineralogical and Environmental Significance

机译：非辐射自然矿物质的辐射诱导：矿物学和环境意义

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Natural sliort-lived radionuclides generate electronic defects in minerals, such as trapped electrons and positive holes, often associated with element impurities, which act as final traps over geological periods. Two main examples will be illustrated. The first example will concern the point defects, which are observed in clay minerals. The high specific surface area makes clay minerals sensitive to the geochemical radiation background and provides a record of the past occurrence of radionuclides in geological systems. In kaolinite, three types of hole-centers are trapped by oxygen atoms linked to Si- or Al-sites. An experimental dosimetry gives the paleodose, which can be used either to assess mean past U-concentration or for kaolinite dating, depending on the available geochemical parameters. The detection of past migrations of radioelements in natural analogues may be used in me safety assessment of radioactive waste disposals. The second example will concern the role of mineral impurities in defect formation and stabilization. Natural fluorites (CaF_2) exhibit hole-and electron-centers trapped on several rare earths and oxygen impurities, often present at the ppm level, which are responsible for the wide range of coloration observed in natural fluorites. Ca colloids may form under severe irradiation and give rise to a characteristic absorption. The thermal stability of radiation-induced defects gives constraints on the evolution of fluorites as a function of temperature and time. Other minerals, such as apatite, confirm the importance of impurities in stabilizing radiation-induced defects over geological periods.
机译：天然的Sliort-Lived放射性核素在矿物质中产生电子缺陷，例如被困的电子和正孔，通常与元素杂质相关，其作为地质时期的最终陷阱。将说明两个主要例子。第一个例子将涉及点缺陷，在粘土矿物中观察到。高比表面积使粘土矿物敏感到地球化学辐射背景，并提供了地质系统中的过去发生的辐射核素的记录。在高岭土中，三种类型的孔中心被与Si-或Al-Sites连接的氧原子捕获。实验剂量测定剂给予古藻糖，其可用于评估平均值过去U-浓度或高岭石，这取决于可用的地球化学参数。在天然类似物中的错弹性迁移的过去迁移的检测可以用于放射性废物处理的安全评估。第二个例子将涉及矿物质杂质在缺陷地层和稳定中的作用。天然萤石（CAF_2）表现出捕获几个稀土和氧气杂质的孔和电子中心，通常存在于PPM水平上，其负责在天然氟化物中观察到的各种着色。 Ca胶体可以在严重照射下形成，并产生特征吸收。辐射诱导的缺陷的热稳定性为温度和时间的函数表示氟化物的演化的约束。其他矿物质如磷灰石，证实了杂质在稳定辐射诱导的地质时期缺陷方面的重要性。

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