Paraxial charge compensator for electron cryomicroscopy
Paraxial charge compensator for electron cryomicroscopy
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DOI：
10.1016/j.ultramic.2012.03.006
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发表时间：
2012-05-01
期刊：
影响因子：
2.2
通讯作者：
Rosenthal, Peter B.
中科院分区：
文献类型：
--
作者：
Berriman, John A.;Rosenthal, Peter B.
我们描述了一个多孔聚光器孔径的透射电子显微镜（TEM）中的几个电子束的生产，使其能够同时成像和照射的样品的空间分离的区域。当试样是一个薄膜的玻璃状冰悬浮在多孔碳膜，同时照射的邻近的碳支持与离轴光束补偿的一些充电的影响，在图像中形成的光束照射只冰。由于中间区域不受辐照，冷冻水合试样的电荷中和可以通过空间穿透机制发生，例如从接地碳支撑膜发射二次电子。我们使用近轴电荷补偿（PCC）来控制样品上的电荷积累量，并观察电荷对图像的影响。因此，多孔孔径提供了一种工具，用于研究在通过低温显微镜对辐射敏感的生物样本进行成像期间的充电和电荷减轻的机制。(C)2012爱思唯尔有限公司版权所有。
We describe a multi-hole condenser aperture for the production of several electron beams in the transmission electron microscope (TEM) making it possible to simultaneously image and irradiate spatially separated regions of a specimen. When the specimen is a thin film of vitreous ice suspended over a holey carbon film, simultaneous irradiation of the adjacent carbon support with the off-axis beam compensates for some of the effects of charging in the image formed by a beam irradiating only the ice. Because the intervening region is not irradiated, charge-neutralization of frozen-hydrated specimens can occur by a through-space mechanism such as the emission of secondary electrons from a grounded carbon support film. We use paraxial charge compensation (PCC) to control the amount of charge build-up on the specimen and observe the effects of charge on images. The multi-hole aperture thus provides a tool for investigating the mechanism of charging and charge mitigation during the imaging of radiation sensitive biological specimens by cryomicroscopy. (C) 2012 Elsevier B.V. All rights reserved.