Movable Emitter Stabilizes Field Emission via Regeneration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric field radiation devices face challenges in stabilizing electron beam emission due to unintended flashover phenomena caused by minute protrusions or gas adsorption on guard electrodes, leading to unstable electron generation and potential X-ray focus issues.
Innovation Solution
The device incorporates a movable emitter supporting unit that adjusts the distance between the emitter and target, allowing for a regeneration process that suppresses field emission from the emitter, enabling the smoothing of guard electrode surfaces without applying voltage to the emitter, thus stabilizing electron generation and improving radiation characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If voltage is applied across the guard electrode to perform regeneration process, then the guard electrode surface is smoothed and flashover is suppressed, but field emission from the emitter also occurs which interferes with the regeneration process
Solution Approach 1:
The emitter position is adjusted beforehand to a position where field emission is suppressed before applying voltage for the regeneration process. This preliminary positioning ensures that when high voltage is applied to the guard electrode for surface smoothing, the emitter does not generate unwanted field emission that would interfere with the regeneration process.
Solution Approach 2:
The emitter supporting unit enables dynamic adjustment of the emitter position along the tube axis. By making the position adjustable, the system can transition between different operational states: during regeneration, the emitter is positioned to suppress field emission, and during normal operation, it is positioned for optimal electron beam generation.
2Reliability
If the emitter position is fixed, then stable field emission current is achieved, but the distance between emitter and target cannot be adjusted for optimizing radiation output
Solution Approach 1:
The emitter supporting unit provides dynamic positioning capability along the tube axis, allowing the emitter to be moved to different distances from the target. This enables optimization of radiation output by adjusting the distance while maintaining stable field emission through proper positioning, thus achieving both reliability and adaptability.
Solution Approach 2:
The emitter supporting unit serves multiple functions: it holds the emitter in position for stable field emission, allows adjustment of the emitter-target distance for optimizing radiation output, and enables positioning at specific locations for regeneration processes. This multi-functionality resolves the contradiction between fixed position stability and adjustable distance versatility.
3Power
If high voltage is applied to the emitter for field emission, then electron beam generation is achieved, but flashover occurs from the guard electrode due to unstable electron generation
Solution Approach 1:
The guard electrode undergoes a preliminary regeneration process where its surface is smoothed by applying voltage and repeating discharge. This preliminary treatment removes minute protrusions and prevents flashover, ensuring stable electron generation from the guard electrode when high voltage is subsequently applied to the emitter for electron beam generation.
Solution Approach 2:
The regeneration process applies voltage to the guard electrode in advance to prevent flashover phenomena. By performing this anti-action (suppressing flashover) before normal operation, the system ensures that when the emitter generates electrons, the guard electrode will not produce unwanted flashover that would destabilize the electron generation.
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 effectively prevents flashover, stabilizes electron beam emission, and allows for precise adjustment of field emission current without altering the tube voltage, enhancing the versatility and performance of electric field radiation devices.
Implementation Method 1
voltage is applied between an emitter (an electron source formed of carbon etc.) and a target which are positioned (which are separated at a predetermined distance) while facing to each other in a vacuum chamber of a vacuum enclosure, an electron beam is emitted by field emission (by generation of electrons and emission of the electrons) of the emitter
Implementation Method 2
by colliding the emitted electron beam with the target, a desired function (for instance, in the case of the X-ray apparatus, a radioscopy resolution by external emission of X-ray) is obtained
Data Source
AI summary
An emitter (3) and a target (7) are arranged so as to face each other in a vacuum chamber (1), and a guard electrode (5) is provided at an outer circumferential side of an electron generating portion (31) of the emitter (3). The emitter (3) is supported movably in both end directions of the vacuum chamber (1) by the emitter supporting unit (4) having a movable body (40). The emitter supporting unit (4) is operated by an operating unit (6) connected to the emitter supporting unit (4). By operating the emitter supporting unit (4) by the operating unit (6), a distance between the electron generating portion (31) of the emitter (3) and the target (7) is changed, and a position of the emitter (3) is fixed at an arbitrary distance, then field emission is performed with the position of the emitter (3) fixed.