论文标题
分辨率和剂量的限制，用于异常校正的电子断层扫描
The Limits of Resolution and Dose for Aberration-Corrected Electron Tomography
论文作者
论文摘要
被像差校正的电子显微镜可以解决自然界中最小的原子键长度。但是，在2D中实现壮观分辨率的高分子角度对除最小的对象（$ <\ sim $ 8nm）以外的所有人都具有未知的3D分辨率限制。我们显示，经过像差校正的电子断层扫描为3D成像提供了新的限制，通过测量每个样品倾斜的几个焦平面。我们通过建立分析性描述，用于分辨率，采样，对象大小和剂量，并与Crowther-Klug标准直接类比，为畸变校正的电子断层扫描提供了理论基础。值得注意的是，经过像差校正的扫描传输电子断层扫描可以测量无界物体大小的完整3D试样结构，直到指定的截止分辨率。当倾斜度增量是收敛角度或更小的两倍时，这打破了已建立的Crowther极限。空前的3D分辨率在大型物体之间是可以实现的。使用可用的显微镜和适度的样品倾斜（$ <$ <$ 3 $^\ circ $），允许允许原子3D成像（1 $ \ unicode {xc5} $）在大于量深度（例如$> 20nm）的扩展对象上。此外，通过畸变校正的断层扫描遵循剂量分级的规则，其中指定的总剂量可以在倾斜和DeDoci之间分配。
Aberration-corrected electron microscopy can resolve the smallest atomic bond-lengths in nature. However, the high-convergence angles that enable spectacular resolution in 2D have unknown 3D resolution limits for all but the smallest objects ($< \sim$8nm). We show aberration-corrected electron tomography offers new limits for 3D imaging by measuring several focal planes at each specimen tilt. We present a theoretical foundation for aberration-corrected electron tomography by establishing analytic descriptions for resolution, sampling, object size, and dose---with direct analogy to the Crowther-Klug criterion. Remarkably, aberration-corrected scanning transmission electron tomography can measure complete 3D specimen structure of unbounded object sizes up to a specified cutoff resolution. This breaks the established Crowther limit when tilt increments are twice the convergence angle or smaller. Unprecedented 3D resolution is achievable across large objects. Atomic 3D imaging (1$\unicode{xC5}$) is allowed across extended objects larger than depth-of-focus (e.g. $>$ 20nm) using available microscopes and modest specimen tilting ($<$ 3$^\circ$). Furthermore, aberration-corrected tomography follows the rule of dose-fractionation where a specified total dose can be divided among tilts and defoci.
