A monochromatic, aberration-corrected, dual-beam low energy electron microscope.
A monochromatic, aberration-corrected, dual-beam low energy electron microscope.
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DOI：
10.1016/j.ultramic.2013.02.018
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发表时间：
2013-07
期刊：
影响因子：
2.2
通讯作者：
Shadman, Khashayar
中科院分区：
文献类型：
--
作者：
Mankos, Marian;Shadman, Khashayar
关键词：
单色、像差校正、双光束低能电子显微镜(MAD-LEEM)是一种以亚纳米分辨率成像纳米结构和表面的新型仪器，它包括单色器、像差校正器和双光束照明。单色器减少了照明电子束的能量扩散，显著提高了光谱和空间分辨率。该像差校正器利用具有负像差的电子镜，该负像差可用于补偿LEEM物镜在一定范围内的电子能量的像差。双重泛光照明消除了传统LEEM用于对绝缘样品成像时产生的电荷。MAD-LEEM是为生物和绝缘样品成像的目的而设计的，这些样品很难用传统的LEEM、低电压扫描电子显微镜和透射电子显微镜成像。MAD-LEEM仪器还可用作分辨率显著提高的通用LEEM。电子的低碰撞能量对于避免束损伤至关重要，因为在扫描电子显微镜和电子显微镜中使用具有keV动能的高能电子会对许多样品造成不可逆转的变化，特别是生物材料。MAD-LEEM的一个潜在应用是DNA测序，这要求成像技术能够以高分辨率、高速度和低成本进行DNA测序。MAD-LEEM方法的主要优点是电子碰撞能低，读取长度长，并且不需要重原子DNA标记。已经开发了对DNA链中单个核苷酸的可检测性的图像对比度模拟，以完善这一应用的光学模糊和DNA碱基对比度要求。
The monochromatic, aberration-corrected, dual-beam low energy electron microscope (MAD-LEEM) is a novel instrument aimed at imaging of nanostructures and surfaces at sub-nanometer resolution that includes a monochromator, aberration corrector and dual beam illumination. The monochromator reduces the energy spread of the illuminating electron beam, which significantly improves spectroscopic and spatial resolution. The aberration corrector utilizes an electron mirror with negative aberrations that can be used to compensate the aberrations of the LEEM objective lens for a range of electron energies. Dual flood illumination eliminates charging generated when a conventional LEEM is used to image insulating specimens. MAD-LEEM is designed for the purpose of imaging biological and insulating specimens, which are difficult to image with conventional LEEM, Low-Voltage SEM, and TEM instruments. The MAD-LEEM instrument can also be used as a general purpose LEEM with significantly improved resolution. The low impact energy of the electrons is critical for avoiding beam damage, as high energy electrons with keV kinetic energies used in SEMs and TEMs cause irreversible change to many specimens, in particular biological materials. A potential application for MAD-LEEM is in DNA sequencing, which demands imaging techniques that enable DNA sequencing at high resolution and speed, and at low cost. The key advantages of the MAD-LEEM approach for this application are the low electron impact energies, the long read lengths, and the absence of heavy-atom DNA labeling. Image contrast simulations of the detectability of individual nucleotides in a DNA strand have been developed in order to refine the optics blur and DNA base contrast requirements for this application.
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影响因子：
1.4
作者：
Mankos, Marian;Shadman, Khashayar;Davis, Ronald W.
通讯作者：
Davis, Ronald W.
DOI：
10.1016/j.nima.2003.11.159
发表时间：
2004-02-21
影响因子：
1.4
作者：
Wan, W;Feng, J;Robin, DS
通讯作者：
Robin, DS
影响因子：
2.2
作者：
Krivanek, OL;Dellby, N;Lupini, AR
通讯作者：
Lupini, AR
DOI：
10.1016/j.nima.2010.11.130
发表时间：
2011-07-21
影响因子：
1.4
作者：
Mankos, Marian
通讯作者：
Mankos, Marian
DOI：
10.1093/oxfordjournals.jmicro.a023610
发表时间：
1998-01-01
期刊：
JOURNAL OF ELECTRON MICROSCOPY
影响因子：
--
作者：
Haider, M;Rose, H;Urban, K
通讯作者：
Urban, K