减小偏差校正的发射量II:电子显微镜的基于物理的贝叶斯优化
Desheng Ma1, Steven E Zeltmann2, Chenyu Zhang1
1School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA.
Ultramicroscopy
|April 12, 2025
概括
我们开发了一种贝叶斯式方法,在扫描传输电子显微镜 (STEM) 中自动纠正偏差. 这种方法使用光束发射和深度神经网络来实现更快,更准确的原子级材料分析.
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:
- 偏差校正扫描传输电子显微镜 (STEM) 对于原子级材料分析至关重要.
- 手动调整偏差校正器是复杂的,耗时的,容易产生噪音.
- 精确测量电子显微镜的光学状态是具有挑战性的.
研究的目的:
- 开发一种完全自动化的贝叶斯方法来纠正STEM中的偏差.
- 尽量减少光束发射量作为质量指标,相当于偏差校正.
- 为了提高实现亚斯特罗姆探测器的速度和准确性.
主要方法:
- 使用贝叶斯优化框架,将光束发射率作为目标函数.
- 采用深度神经网络来预测来自Ronchigram图像的光束发射率增长.
- 探索了各种代用函数,并实施了深度神经网络内核以进行优化.
主要成果:
- 演示了模拟和真实电子显微镜的自动调整.
- 与传统方法相比,贝叶斯方法实现了更高的融合率.
- 该方法成功优化了光学状态,从而提高了探头质量.
结论:
- 开发的贝叶斯方法有效地自动化了STEM偏差校正.
- 尽量减少光束发射提供了一个高效和准确的质量指标.
- 这种方法在速度和精度上明显优于传统的调方法.
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