Electron Gun Extraction Electrode Cooling for Stable Beam Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional charged particle guns experience uneven temperature distribution and thermal expansion in the extraction electrode due to increased heat generation, leading to unstable operation and reduced throughput when high amounts of charged particles are emitted.
Innovation Solution
A charged particle gun with an auxiliary structure in contact with the extraction electrode to enhance heat conduction, stabilizing the temperature distribution and maintaining consistent charged particle emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the amount of charged particles emitted from the charged particle source is increased to improve throughput, then productivity is improved, but heat generation and thermal expansion occur in the extraction electrode causing unstable operation
Solution Approach 1:
A heat transfer structure is introduced as an intermediary component between the extraction electrode and the housing. This mediator facilitates efficient heat conduction away from the extraction electrode, allowing high charged particle emission rates to be maintained without causing thermal expansion that would destabilize the central axis alignment. The heat transfer structure acts as a thermal bridge that protects the extraction electrode from excessive heat accumulation.
Solution Approach 2:
The patent replaces reliance on mechanical stability alone with a combined thermal management system. Instead of depending solely on the mechanical rigidity of the extraction electrode mounting, the system introduces active heat conduction pathways through the heat transfer structure. This substitution allows the system to maintain mechanical alignment stability even under high thermal loads by actively managing heat flow rather than passively relying on thermal isolation.
2Productivity
If a voltage of several kV is applied to the extraction electrode to extract charged particles, then charged particle extraction efficiency is improved, but electric power generation and heat accumulation occur in the extraction electrode
Solution Approach 1:
The patent converts the harmful heat accumulation effect into a beneficial thermal management opportunity. By applying high voltage to achieve efficient charged particle extraction, the system intentionally allows heat generation but then uses the heat transfer structure to conduct this heat away systematically. The heat that would otherwise be a harmful accumulation is redirected through controlled conduction pathways to the housing, where it can be dissipated. This transforms the adverse thermal effect into a manageable thermal flow that supports sustained high-efficiency operation.
3Ease of manufacture
If the extraction electrode is connected to the extraction electrode base with a screw, then assembly is simplified, but heat conduction around the screw is small causing temperature difference and local thermal expansion
Solution Approach 1:
The patent segments the heat conduction function from the mechanical fastening function. Instead of relying on the screw to perform both mechanical assembly and thermal conduction (which creates thermal resistance), the system separates these functions: the screw provides simple mechanical assembly while the dedicated heat transfer structure provides efficient thermal conduction. This segmentation allows each component to optimize its primary function without compromising the other, maintaining both ease of assembly and temperature distribution uniformity.
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
The auxiliary structure improves thermal conductivity, suppressing thermal expansion and ensuring stable operation for extended periods, enhancing throughput and maintainability.
Implementation Method 1
an auxiliary structure in contact with the extraction electrode to enhance heat conduction, stabilizing the temperature distribution
Implementation Method 2
charged particles collide with a surface disposed perpendicular to the optical axis to generate heat
Implementation Method 3
heat generation and thermal expansion occur in the extraction electrode
Data Source
AI summary
An electron gun 901 capable of suppressing an uneven temperature distribution at an extraction electrode and a length-measuring SEM 900 are provided. The electron gun 901 is equipped with: a charged particle source 1; an extraction electrode 3 for extracting charged particles from the charged particle source 1 and allowing some of the charged particles to pass while blocking some other charged particles; and an auxiliary structure 5 disposed in contact with the extraction electrode 3. The length-measuring SEM 900 is equipped with the electron gun 901 and a computer system 920 for controlling the electron gun 901.