设计和评估一种新的法拉第杯,用于在传输电子显微镜中轻松准确地测量束电流
Ehsan Nikbin1, Dian Yu1, Ilya Gourevich2
1Department of Materials Science & Engineering, University of Toronto, Toronto, ON, Canada.
概括
传输电子显微镜 (TEM) 的新法拉第杯设计提供了精确的电子束电流测量. 这种具有成本效益的工具很容易找到,并与TEM持有器无集成,改进了对光束敏感样本的分析.
科学领域:
- 材料科学 材料科学 材料科学
- 分析化学 分析化学
- 物理 物理学 物理
背景情况:
- 精确的电子束电流测量对于在电子显微镜中量化电子剂量至关重要,特别是对于对电子束敏感的样本.
- 传输电子显微镜 (TEM) 现有的法拉第杯通常是昂贵的,可用性有限,难以准确定位.
- 传统法拉第杯在TEM中的隐形性阻碍了精确的对齐和使用.
研究的目的:
- 为传输电子显微镜 (TEM) 开发一种新,实用且具有成本效益的法拉第杯.
- 设计一个易于定位和兼容标准TEM持有器和样本网格的法拉第杯.
- 通过实验测量和模拟来验证新的法拉第杯设计的准确性和性能.
主要方法:
- 设计了一个新的法拉第杯,具有对称的穿孔,以方便定位,并将其集成到 Hitachi HT7700/HT7800 系列的绝缘 TEM 支架中.
- 在持有器内安装了3毫米的TEM网格,允许同时采样成像和法拉第杯访问.
- 采用实验测量和蒙特卡洛模拟,变化直径至深度比和材料以优化性能.
- 在不同的电子能量中评估精度.
主要成果:
- 新的法拉第杯设计允许在TEM中轻松进行视觉识别和精确定位.
- 实验和模拟结果表明,电子束电流测量精度优于1-2%.
- 通过使用直径为0.2毫米,深度为0.8毫米的杯进行了优化配置.
- 该设计确保在一系列电子能量范围内进行准确的测量.
结论:
- 开发的法拉第杯提供了一种实用,简单和负担得起的解决方案,用于在TEM中精确测量光束电流.
- 这项创新提高了对光束敏感样品精确估计电子剂量的能力.
- 设计方便常规使用,提高了定量电子显微镜的可靠性.
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