Field Emitter Core and Wire Structure for X-ray Tubes
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Solution Overview
Problem
Current field emission devices face challenges in achieving high-current emitter characteristics, easy manufacturing, and durability, particularly in X-ray tubes, where the emitter structure needs to efficiently concentrate electric fields for effective electron emission.
Innovation Solution
A field emission device design featuring a cathode electrode with recessed grooves and emitter structures within these grooves, where the emitter structures include a core and a conductive wire, such as carbon nanotubes, arranged in a specific configuration to enhance electron emission efficiency and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nanomaterials with sharp tips are used as emitters to concentrate electric fields, then electron emission efficiency is improved, but manufacturing difficulty increases
Solution Approach 1:
The emitter structure is segmented into a core and multiple conductive wires surrounding it, with each component having a simplified geometry that is easier to manufacture individually while collectively achieving the desired electric field concentration effect
Solution Approach 2:
The emitter uses a composite structure combining a core material with surrounding conductive wire materials, where each material can be optimized for its specific function and manufactured using appropriate processes, then assembled together
2Reliability
If complex emitter structures are designed to improve field emission performance, then electron emission efficiency is improved, but device durability decreases
Solution Approach 1:
The conductive wires are positioned to surround and protect the core emitter structure, providing mechanical support and stress distribution that prevents premature failure while maintaining the sharp tip geometry needed for electron emission
Solution Approach 2:
The combination of core and surrounding conductive wires creates a composite emitter structure where each component contributes to both emission performance and structural durability, with the outer wires providing mechanical reinforcement
3Reliability
If multiple emitter components are assembled to achieve desired configuration, then electron emission efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The conductive wires are arranged to surround the core in a nested configuration, where simpler cylindrical components are assembled around a central core, creating the desired complex electric field distribution through a systematic nesting pattern that simplifies the assembly process
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 design improves electron emission efficiency and durability, facilitating the production of field emission devices with enhanced performance for applications like X-ray tubes by concentrating electric fields effectively and maintaining structural integrity.
Implementation Method 1
Nanomaterials used as emitters may emit electrons to the outside of nanomaterials through a quantum tunneling effect caused by external electric fields
Implementation Method 2
In the case in which the tip of each of the emitters has the sharp shape, electric fields may be concentrated into the tips of the emitters to improve the electron emission efficiency
Data Source
AI summary
Provided is a field emission device. The field emission device includes a cathode electrode having a first surface and a second surface facing the first surface, the cathode electrode including grooves that are recessed from the first surface toward the second surface, the grooves extending in a first direction parallel to the first surface and emitter structures which are disposed within the grooves and each of which includes a core extending in the first direction and a conductive wire configured to surround the core. The grooves may be arranged in a second direction crossing the first direction, and the emitter structures may be disposed at vertical levels different from each other.