Multi-Grid X-Ray Source for Arc and Ion Shielding
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Solution Overview
Problem
Arcing and ion back bombardment in x-ray tubes can damage internal components such as the cathode, particularly nanotube emitters, due to high-energy ion pulses and ionization of residual gas species.
Innovation Solution
Incorporating multiple grids, including a first grid to control field emission and a second grid positioned between the first grid and the anode, which intercepts arcs and ions, reducing the risk of damage to the field emitter by providing a path for arcs and decelerating ions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single grid is used to control field emission, then the device complexity is low, but the field emitter is vulnerable to arc damage and ion bombardment
Solution Approach 1:
A second grid is introduced as an intermediary component between the first grid and the anode. This second grid serves as a protective mediator that intercepts arcs and ions before they reach the field emitter, thereby protecting the field emitter from damage while maintaining the field emission control function of the first grid
Solution Approach 2:
The single grid control function is segmented into two separate grids: the first grid maintains the primary field emission control function, while the second grid is dedicated to protecting against arc and ion damage. This segmentation allows each grid to specialize in one function, improving overall reliability without requiring the first grid to perform multiple conflicting functions
2Object-affected harmful factors
If no additional protective grids are used, then the device complexity remains low, but arcs and ions can directly damage the field emitter
Solution Approach 1:
The second grid is positioned to intercept harmful arcs and ions, converting the harmful direct impact on the field emitter into a controlled interaction at the second grid. The harmful kinetic energy of ions is dissipated at the second grid rather than reaching the field emitter, and arcs are terminated at the second grid instead of damaging the field emitter
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 additional grids effectively reduce the likelihood of damage to the field emitter by diverting arcs and shielding ions, thereby enhancing the durability and operational stability of the x-ray source.
Implementation Method 1
a first grid configured to control field emission from the field emitter
Implementation Method 2
Arcing and ion back bombardment may occur in x-ray tubes. For example, an arc may form in a vacuum or dielectric of an x-ray tube.
Implementation Method 3
These charged particles may be accelerated towards the cathode, potentially causing damage.
Data Source
AI summary
Some embodiments include an x-ray source, comprising: an anode; a field emitter configured to generate an electron beam; a first grid configured to control field emission from the field emitter; a second grid disposed between the first grid and the anode; a third grid disposed between the first grid and the anode; and a middle electrode disposed between the first grid and the anode wherein the second grid is either disposed between the first grid and middle electrode or between the middle electrode and the anode; wherein the third grid is a mesh grid.