X-ray tube drift-tube protrusions for backscatter suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
X-ray tubes experience electron backscatter leading to charge build-up on insulative cylinders, causing voltage gradients and arcing failures, which shifts the electron beam away from the target, making it difficult to aim the x-ray beam effectively.
Innovation Solution
The use of a drift-tube with protrusions on its interior surface to capture and redirect backscattered electrons back to the target, reducing charge accumulation and voltage gradients by grounding the drift-tube and attaching it to the anode, and optimizing the shape and placement of these protrusions to enhance electron capture and reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If electrons are sent across a voltage differential to a target to generate x-rays, then x-rays are produced, but some electrons rebound and cause charge build-up on insulative cylinders leading to voltage gradients and arcing failure
Solution Approach 1:
A drift tube is introduced as an intermediary component between the insulative cylinder and the electron beam path. The drift tube captures backscattered electrons through its protrusions and redirects them to the target, preventing charge accumulation on the insulative cylinder while maintaining x-ray generation capability
Solution Approach 2:
The harmful backscattered electrons that would normally cause charge build-up are converted into a beneficial function by redirecting them back to the target using the drift tube protrusions. This transforms the harmful electron rebound into an additional source of x-ray generation while eliminating the reliability issue
2Power
If charge builds unevenly on the walls of the x-ray tube, then x-rays are emitted from different locations of the target, but this shifts the electron beam away from the center making it difficult to aim
Solution Approach 1:
The drift tube is grounded to create an equipotential surface, eliminating voltage gradients caused by uneven charge distribution. This ensures the electron beam remains centered on the target and maintains precise aiming capability while x-rays are still generated
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 solution significantly reduces electron backscatter, minimizing charge build-up and arcing failures, allowing for a more stable and accurately aimed x-ray beam by effectively capturing backscattered electrons and maintaining a hermetic seal.
Implementation Method 1
But some electrons rebound, and fail to form x-rays. These electrons can cause an electrical charge to build-up on an inside of the x-ray tube.
Implementation Method 2
An x-ray tube makes x-rays by sending electrons, in an electron-beam, across a voltage differential, to a target.
Implementation Method 3
grounding the drift-tube and attaching it to the anode
Implementation Method 4
The use of a drift-tube with protrusions on its interior surface to capture and redirect backscattered electrons back to the target
Data Source
AI summary
Electrons can rebound from an x-ray tube target, causing electrical-charge build-up on an inside of the x-ray tube. The charge build-up can increase voltage gradients inside of the x-ray tube, resulting in arcing failure of the x-ray tube. Also, the electrical charge can build unevenly on internal walls of the x-ray tube, causing an undesirable shift of the electron-beam. An x-ray tube (10 or 20) with multiple protrusions (19) on an interior wall of a drift-tube (18) can reduce this electrical-charge build-up. The protrusions (19) can reflect stray electrons back to the anode target (14), thus suppressing backscatter. Each protrusion (19) can have a peak (19p) extending into the hole (18h), and receding to a base (19b) farther from the electron-beam, on an entry-side (19en) nearest the drift-tube-entry (18en) and on an exit-side (19ex) nearest the drift-tube-exit (18ex).