Segmented DPC Detector for Simultaneous Phase Contrast and EELS
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Solution Overview
Problem
Current detector configurations in charged particle systems cannot simultaneously perform phase contrast imaging and energy loss spectroscopy due to blocking of high-scattering-angle electrons, limiting the ability to image both light and heavy atoms effectively.
Innovation Solution
A method and system that use a first detector centered at the primary axis and a second detector downstream, with charged particle transparent regions allowing high-scattering-angle electrons to reach the second detector without compromising phase contrast image quality, enabling simultaneous acquisition of structural and compositional information by overlapping exit angles of transmitted charged particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a segmented DPC/iDPC detector is positioned downstream of the sample to perform phase contrast imaging, then sub-A resolution structural information can be acquired, but high-scattering-angle electrons required for EELS are blocked
Solution Approach 1:
The detector is divided into multiple segments arranged in a windmill pattern, with each segment detecting electrons from specific angular ranges. The gaps between segments allow high-scattering-angle electrons to pass through to the EELS spectrometer while the segments capture phase contrast information from their respective angular zones
Solution Approach 2:
The detector segments are arranged azimuthally around the primary beam axis rather than in a linear array, creating a three-dimensional detection geometry that captures electrons from different angular directions simultaneously, allowing both phase contrast and EELS signals to be collected
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for the simultaneous acquisition of structural and compositional information, including high-scattering-angle electrons, without sacrificing image quality, enabling comprehensive imaging of samples containing both light and heavy atoms.
Implementation Method 1
electrons transmitted through the sample are spatially dispersed by a spectrometer based on the electron energy
Implementation Method 2
electrons transmitted through the sample are spatially dispersed by a spectrometer based on the electron energy and collected as a spectrum by a detector downstream of the spectrometer
Data Source
Figure 1
Figure 2
Figure 3A~4D
AI summary
A method and system for imaging a sample (60) with charged particles comprises directing charged particles (111) towards the sample along a primary axis, and simultaneously detecting a first portion and a second portion of the charged particles transmitted through the sample (261-265) with a first detector (250) and a second detector (270), respectively. The second detector is positioned downstream of the first detector. Each of the transmitted charged particles exits the sample at an exit angle (210) between a direction of the transmitted charged particle and the primary axis. The exit angles of the first portion of the transmitted charged particles overlap with the exit angles of the second portion of the transmitted charged particles. In this way, complementary information, such as the structural and compositional information, may be obtained simultaneously.