Hollow Cathode Electron Beam Source with De Laval Nozzle
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Solution Overview
Problem
Existing electron beam sources face issues with directing and dispersion of the electron packet, limited mean energy due to capillary tube ablation, contamination of the target material, and geometric constraints that hinder industrial scaling and require frequent maintenance of capillary tubes.
Innovation Solution
A device comprising a hollow cathode with a trigger electrode and a pressure regulation system to generate plasma and direct an electron beam towards a target, using a de Laval nozzle for acceleration and minimizing impurities by maintaining a high pressure gradient within the device, allowing for precise control of the electron beam and reducing the need for capillary tubes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a capillary tube is used to guide the electron beam, then the electron beam can be directed with reduced spatial dispersion, but the mean energy of electrons is limited due to capillary tube ablation and contamination of target material
Solution Approach 1:
The patent removes the capillary tube from the system entirely, replacing it with a direct electron beam generation and acceleration mechanism. The hollow cathode structure generates plasma and accelerates electrons without requiring a physical guiding tube, thereby eliminating the source of ablation and contamination while maintaining beam directionality through electric field control.
Solution Approach 2:
The patent replaces the mechanical capillary tube guidance system with an electromagnetic field-based electron acceleration and direction system. The hollow cathode and anode configuration creates electric fields that guide and accelerate electrons without physical contact, substituting mechanical guidance with electromagnetic control to avoid material degradation.
2Manufacturing precision
If a capillary tube is used to guide the electron beam, then electron direction is improved, but the device requires frequent maintenance and replacement of capillary tubes
Solution Approach 1:
The patent eliminates the capillary tube component entirely by using a hollow cathode structure that generates and directs electrons through electric fields. This removal of the fragile capillary tube component eliminates the need for frequent maintenance and replacement, while the electric field-based electron guidance maintains precise beam direction.
Solution Approach 2:
The hollow cathode structure is designed to be robust and maintenance-free, generating plasma and accelerating electrons through its inherent electric field configuration. The system is self-sustaining without requiring periodic intervention for capillary tube replacement, improving ease of operation and reducing maintenance overhead.
3Device complexity
If the electron beam is propagated in free space with stationary residual gas, then the system is simpler, but the electron packet experiences spatial and energy dispersion
Solution Approach 1:
The patent changes the pressure parameter within the hollow cathode to an optimized range that balances two opposing effects: high enough to generate sufficient plasma density for electron multiplication, but low enough to minimize spatial and energy dispersion of the electron beam. This parameter optimization allows the system to maintain beam monochromaticity while operating with a simpler structure compared to capillary tube systems.
4Quantity of substance
If the pressure in the vacuum chamber is increased to form a plasma cathode, then the electron beam charging density is intensified, but energy dispersion occurs due to electron impact with residual gas atoms
Solution Approach 1:
The patent optimizes the pressure parameter within the hollow cathode to achieve a balance between plasma density and beam quality. The pressure is maintained at a level that provides sufficient plasma cathode for high electron charging density while minimizing energy dispersion through controlled electron-gas interactions. This parameter optimization enables the system to achieve high beam intensity with acceptable energy monochromaticity.
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 solution achieves precise control and high-intensity electron beam delivery with reduced dispersion and impurities, enhancing the efficiency and longevity of the electron beam source, eliminating the need for frequent maintenance and scaling limitations.
Implementation Method 1
a device for generating plasma and for directing an electron beam towards a target
Implementation Method 2
The generation and conveying of the electron beam often occurs in an environment with an ultra-high vacuum
Implementation Method 3
using a de Laval nozzle for acceleration and minimizing impurities by maintaining a high pressure gradient within the device
Implementation Method 4
using a de Laval nozzle for acceleration
Implementation Method 5
directing an electron beam towards a target, which comprises (in particular is constituted of) the predetermined material, in such a way that at least part of the predetermined material is separated from the target
Implementation Method 6
at least part of the predetermined material is separated from the target
Data Source
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AI summary
A device (2; 2I; 2II; 2IV; 2V; 2VI; 2VII; 2VIII) for generating plasma and for directing an electron beam towards a target (3); the device (2; 2I; 2II; 2IV; 2V; 2VI; 2VII; 2VIII) comprises a hollow element (5); an activation group (21), which is designed to impose a difference in potential between the hollow element (5) and another element which is separate from it, in such a way as to direct the electron beam towards said separate element; and a de Laval nozzle (23), having at least one tapered portion (13), which is tapered towards the separate element and is designed to accelerate a gas flow towards the separate element.