Ion Generator Arc Chamber Materials for Pure Multiply Charged Ions
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Solution Overview
Problem
Existing ion generators face challenges in generating high-purity multiply charged ions while suppressing contamination and damage due to electric discharges, especially when operating at conditions that require increased arc voltage or current.
Innovation Solution
The ion generator incorporates a refractory metal material for the inner surface of the arc chamber and graphite for the inner surface of the slit member, combined with a specific configuration of the cathode and repeller, to minimize contamination and electric discharge damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If arc voltage or arc current is increased to generate sufficient multiply charged ions, then ion generation capability is improved, but wear of arc chamber and electric discharge damage increase
Solution Approach 1:
The patent applies different materials to different parts of the arc chamber: refractory metal material for the main body and graphite for the slit member. This local differentiation allows each component to be optimized for its specific function and exposure conditions, enabling the system to operate at higher arc voltages and currents necessary for generating multiply charged ions while managing the localized wear and discharge damage through material-specific resistance properties.
Solution Approach 2:
The patent employs a composite material approach by combining refractory metal material and graphite in the arc chamber structure. This composite construction leverages the high melting point and structural integrity of refractory metals for the main chamber body while utilizing graphite's excellent electrical conductivity and resistance to arc erosion for the slit member, thereby enabling sustained operation at elevated arc parameters required for multiply charged ion generation.
2Strength
If refractory metal material is used for arc chamber inner surface, then resistance to wear and high temperature is improved, but contamination risk increases
Solution Approach 1:
The patent applies refractory metal material specifically to the main body of the arc chamber where high temperature and mechanical wear are primary concerns, while using graphite for the slit member where electrical conductivity and arc resistance are more critical. This localized material assignment minimizes contamination by ensuring each material is used where its dominant properties provide the greatest benefit while reducing overall system contamination.
3Reliability
If graphite is used for slit member inner surface, then electrical conductivity and arc resistance are improved, but mechanical strength decreases
Solution Approach 1:
The patent assigns graphite specifically to the slit member where electrical conductivity and resistance to arc erosion are the primary functional requirements, while relying on the refractory metal main body for structural support. This local specialization allows the graphite slit member to maintain excellent electrical properties without compromising overall mechanical integrity, as the refractory metal framework provides the necessary structural strength.
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 enables the stable generation of high-purity multiply charged ions, reduces contamination and wear, and minimizes the risk of electric discharge damage, thereby improving the operational efficiency and lifespan of the ion generator.
Implementation Method 1
a cathode which emits thermoelectrons toward the plasma generation space
Implementation Method 2
an arc chamber which defines a plasma generation space
Data Source
AI summary
An ion generator includes an arc chamber defining a plasma generation space, and a cathode which emits thermoelectrons toward the plasma generation space. The arc chamber includes a box-shaped main body having an opening, and a slit member mounted to cover the opening and provided with a front slit. An inner surface of the main body is exposed to the plasma generation space made of a refractory metal material. The slit member includes an inner member made of graphite and an outer member made of another refractory metal material. The outer member includes an outer surface exposed to an outside of the arc chamber. The inner member includes an inner surface exposed to the plasma generation space, and an opening portion which forms the front slit extending from the inner surface of the inner member to the outer surface of the outer member.