Electron Microscope Gas Atmosphere Observation Vacuum Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In in-situ observations using electron microscopes, detectors requiring voltage application, such as secondary electron detectors, face electric discharge issues in gas atmospheres, limiting the ability to observe three-dimensional sample changes, and existing detectors like ESED and UV detectors are ineffective in low vacuum states below 50 Pa.
Innovation Solution
An electron microscope system with a detector for secondary electrons, a gas inlet device, and a gas control mechanism to maintain the vacuum level below a set value, preventing electric discharge by controlling gas emission and ensuring the detector operates safely in a gas atmosphere.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a detector requiring voltage application (such as secondary electron detector) is used in gas atmosphere for in-situ observation, then three-dimensional sample changes can be observed, but electric discharge occurs preventing the detector from operating
Solution Approach 1:
The observation space is divided into two distinct regions: a first space (sample chamber) where gas atmosphere exists for in-situ observation, and a second space (detector chamber) maintained in vacuum state for detector operation. A partition wall with an opening separates these spaces, allowing electrons to pass while preventing gas mixing. This spatial segmentation enables the secondary electron detector to operate in vacuum while the sample is observed in gas atmosphere, resolving the electric discharge problem.
Solution Approach 2:
A partition wall with an opening acts as an intermediary structure between the gas atmosphere space and the vacuum space. The partition wall maintains the vacuum barrier while its opening allows electron transmission from the sample in gas atmosphere to the detector in vacuum. This intermediary structure enables simultaneous maintenance of different atmospheric conditions in adjacent spaces.
2Loss of information
If transmission electron microscopic image is used for in-situ observation, then two-dimensional changes can be observed, but three-dimensional changes cannot be observed
Solution Approach 1:
The system merges two previously separate observation capabilities into a single integrated system: transmission electron microscopy (for two-dimensional internal structure observation) and secondary electron microscopy (for three-dimensional surface morphology observation). By combining both detectors in the same instrument with different observation spaces, the system can simultaneously or alternately acquire both two-dimensional and three-dimensional information from the sample in gas atmosphere.
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
Enables the use of voltage-applying detectors for in-situ observations in gas atmospheres, allowing for the simultaneous observation of both two-dimensional and three-dimensional sample changes without electric discharge, enhancing the capability to study catalysts and other samples.
Implementation Method 1
an electron beam from an electron gun
Implementation Method 2
an electron generated when a sample is illuminated with an electron beam
Implementation Method 3
a gas control device which controls a gas emitting amount of the gas inlet device so that a degree of vacuum in a space in which the detector is installed may continuously be kept at less than a set value during gas emission
Data Source
AI summary
An electron microscope includes a secondary electron detector (51) which detects an electron generated when a sample (70) is illuminated with an electron beam from an electron gun (1), a monitor (39) which displays a secondary electron image of the sample based on an output of the detector, a gas inlet device (60) which emits gas to the sample, and a gas control device (81) which controls a gas emitting amount of the gas inlet device so that a degree of vacuum in an intermediate chamber (74) in which the secondary electron detector is installed may be kept at less than a set value P1 during gas emission performed by the gas inlet device. Accordingly, a microscopic image of the sample in a gas atmosphere with use of the detector requiring application of voltage is obtained.