SiPM Scintillator Detector for Electron Microscopy
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Solution Overview
Problem
Current electron detectors in electron microscopes are large, require high voltage, and need a light guide, limiting their placement and efficiency, and cannot operate at low vacuum levels, which restricts their use and increases complexity and cost.
Innovation Solution
The use of an electron detector system that includes an SiPM directly coupled with a scintillator without a light guide, allowing for high gain, small size, and low voltage operation, enabling placement within the electron column and efficient light collection, and capable of operating in low vacuum environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a light guide is used to couple the scintillator to the photomultiplier tube, then light collection efficiency is improved, but device size and complexity increase
Solution Approach 1:
The patent removes the light guide component from the detector assembly, directly coupling the scintillator to the photomultiplier tube. This extraction of the light guide simplifies the device structure while maintaining effective light transmission through direct optical contact between the scintillator and PMT photocathode.
Solution Approach 2:
The patent merges the scintillator and photomultiplier tube into a closely integrated assembly where the scintillator is directly coupled to the PMT photocathode. This merging eliminates the need for separate light guide components and their associated mounting structures, reducing overall device complexity.
2Measurement precision
If a photomultiplier tube is used for electron detection, then detection sensitivity is improved, but device size and operating voltage requirements increase
Solution Approach 1:
The patent segments the detector into compact components with the scintillator positioned immediately adjacent to the PMT photocathode. This segmentation allows the detector to be divided into functional zones that can be tightly integrated, reducing the overall volume while maintaining PMT-based sensitivity.
Solution Approach 2:
The patent optimizes the spatial arrangement by positioning the scintillator in direct contact with the PMT photocathode surface, utilizing the two-dimensional interface between these components. This dimensional optimization allows efficient light collection without requiring additional space for light guides or complex optical paths.
3Ease of operation
If the detector is placed outside the electron column, then access to the sample chamber is simplified, but imaging resolution and information content are reduced
Solution Approach 1:
The patent creates a detector design that can function effectively in multiple locations - both inside the electron column and in the sample chamber. The compact scintillator-PMT assembly is versatile enough to be positioned in various configurations, allowing the same detector design to serve multiple functional roles and locations.
Solution Approach 2:
The patent changes the physical parameters of the detector assembly by removing the light guide and directly coupling the scintillator to the PMT. This parameter change reduces the detector's overall size and allows it to be positioned in locations previously inaccessible, such as within the electron column or in close proximity to the sample chamber.
4Adaptability or versatility
If multiple detectors are installed in the sample chamber, then multiple imaging perspectives are achieved, but available access ports are consumed
Solution Approach 1:
The patent segments the detection system into multiple independent compact detector units, each capable of providing a specific imaging perspective. These segmented detectors can be distributed throughout the sample chamber without requiring a single large access port, as each unit is self-contained and can be positioned independently.
Solution Approach 2:
The patent implements a nested arrangement where multiple detector elements are positioned in a compact configuration within the sample chamber. The detectors can be arranged in nested or overlapping positions, allowing multiple imaging perspectives to be achieved from a limited space without consuming additional access ports.
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 configuration allows for high-resolution imaging at fast scanning rates, reduces complexity and cost, and frees up access ports for other analytical tools, enabling multiple imaging perspectives and improved information content.
Implementation Method 1
the scintillator is structured to emit photons when impinged by electrons ejected from the specimen
Implementation Method 2
the SiPM is structured to generate a signal responsive to receipt of the photons from the scintillator
Data Source
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AI summary
A charged particle beam device includes an electron source structured to generate an electron beam, the electron source being coupled to an electron column that at least partially houses a system structured to direct the electron beam toward a specimen positioned in a sample chamber to which the electron column is coupled, and an electron detector. The electron detector includes one or more assemblies positioned within the electron column or the sample chamber, each of the assemblies including an SiPM and a scintillator directly connected face-to-face to an active light sensing surface of the SiPM without a light transporting device being positioned in between the scintillator and the SiPM.