X-ray tube throat with varying wall thickness for eddy current reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional x-ray tubes face challenges in achieving rapid transient response due to eddy currents generated in the throat portion, which slow down the magnetic field deflection and refocusing of the electron beam, affecting image quality and thermal management.
Innovation Solution
The x-ray tube design incorporates a throat portion with varying wall thicknesses and a magnetic field section that minimizes eddy current generation, allowing for faster magnetic field rise times and improved electron beam control, while maintaining structural integrity and hermeticity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the throat portion has uniform wall thickness, then manufacturing is simpler and structural integrity is maintained, but eddy currents are generated that slow down magnetic field rise time
Solution Approach 1:
The throat portion is designed with non-uniform wall thickness, where the wall thickness varies along the length of the throat. Specifically, the wall thickness is greater at the upstream end (closer to the cathode) and decreases toward the downstream end (closer to the target). This local variation in geometry reduces eddy current generation in regions where the magnetic field changes most rapidly, thereby improving magnetic field rise time without requiring complete redesign of the entire throat structure.
2Loss of energy
If the wall thickness in the magnetic field section is reduced, then eddy current losses are minimized and transient response is improved, but structural strength and hermeticity may be compromised
Solution Approach 1:
The wall thickness parameter of the throat portion is explicitly varied along its length. By changing this geometric parameter from uniform to non-uniform distribution, the patent optimizes the balance between reducing eddy current losses (which occur primarily in thinner sections) and maintaining structural integrity (which requires sufficient thickness). The specific profile of wall thickness variation is designed to minimize energy losses while preserving mechanical strength and hermetic sealing capability.
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 design enhances the transient response of the x-ray tube, leading to improved image quality and reduced thermal loading, with a potential 50% improvement in magnetic field rise time and effective heat management.
Implementation Method 1
when current in the electromagnets is rapidly changed to generate the changing magnetic field, eddy currents are generated in the vacuum vessel wall that opposes the magnetic field penetration inside the x-ray tube. The eddy currents increase the rise time of the magnetic field inside the throat of the x-ray tube
Data Source
AI summary
An x-ray tube assembly includes a vacuum enclosure including a cathode portion, a target portion, and a throat portion. The throat portion includes a magnetic field section, upstream section, and downstream section. The magnetic field section has a first susceptibility to generate eddy currents in the presence of a magnetic field intensity. The upstream section is coupled to the cathode portion and the magnetic field section and has a second susceptibility to generate eddy currents in the presence of the magnetic field intensity. The downstream section is coupled to the magnetic field section and has a third susceptibility to generate eddy currents in the presence of the magnetic field intensity. The first susceptibility to generate eddy currents is less than the second and third susceptibilities to generate eddy currents. The assembly includes a target within the target portion, and a cathode within the cathode portion.