Dynamic focussing for recording images from tilted samples in small-spot scanning with a transmission electron microscope.
Dynamic focussing for recording images from tilted samples in small-spot scanning with a transmission electron microscope.
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动态聚焦，用于使用透射电子显微镜在小光斑扫描中记录倾斜样品的图像。
DOI：
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发表时间：
1989
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通讯作者：
F. Zemlin
中科院分区：
文献类型：
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作者：
F. Zemlin
对于三维电子显微结构的研究，样品必须在倾斜的位置成像。通常还需要样品倾斜以实现最佳的分子堆积取向。相对于光轴的倾斜导致成像区域旁边的散焦梯度，并因此带来以下复杂性：1）对于强散焦，相衬传递函数衰减; 2）傅立叶系数分裂;以及3）不能通过简单的平均来增强信噪比。提出了一种小光斑扫描同时进行离焦补偿的成像方法，有助于减少这些问题。
For three-dimensional electron microscopical structure research the specimen must be imaged in a tilted position. Specimen tilt is also often needed to achieve an optimal molecular packing orientation. The tilt with respect to the optical axis causes a defocus gradient alongside the imaged area and thus entails the following complications: 1) The phase-contrast transfer function fades for strong defocus; 2) the Fourier coefficients are split; and 3) the signal-to-noise ratio cannot be enhanced by simple averaging. An image procedure with small-spot scanning and simultaneous defocus compensation is proposed which helps to reduce these problems.