弹性和无弹性散射的顺序是否会影响图像,还是有无弹性散射的上下效应?
1Department of Physics, Arizona State University, Tempe, AZ 85287-1504, USA.
Ultramicroscopy
|December 19, 2023
概括
在轻元素中常见的不弹性散射与弹性散射是可分离的. 这项研究表明,这些散射事件的顺序不会在成像中产生上下效应.
科学领域:
- 材料科学 材料科学 材料科学
- 物理 物理学 物理
- 电子显微镜电子显微镜
背景情况:
- 对于轻质元素,不弹性散射比弹性散射更有可能发生.
- 弹性散射在成像中提供结构信息.
- 由于散射顺序,在成像中存在"上下效应"的可能性受到质疑.
研究的目的:
- 调查弹性和非弹性散射的顺序是否会影响成像结果.
- 为了确定电子散射中上下效应的存在或不存在.
主要方法:
- 电子散射过程的理论分析.
- 基于角分布的不弹性和弹性散射事件的分离.
- 适用于弱分散的薄生物标本.
主要成果:
- 不弹性散射集中在一个狭窄的角度范围内,在轻元素中明显小于布拉格角度.
- 不弹性和弹性散射过程是可以分离的.
- 一个顶底效应是可以忽略不计的非常好的近似.
结论:
- 散射过程的可分离性消除了光元素电子成像中的上下效应.
- 对于像微薄的生物标本这样的相位物体,分离是精确的,证实没有上下效应.
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