Compact X-ray Source Using Dielectric Electrodes
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Solution Overview
Problem
Current X-ray tube technologies are limited by large dimensions due to constraints such as electrical insulation requirements, parasitic electron emissions, and thermal power dissipation, hindering miniaturization and integration in imaging systems.
Innovation Solution
A compact X-ray source design featuring a vacuum chamber with a dielectric mechanical part and a cold cathode that emits electrons by field effect, using a dielectric material to manage high electric fields and eliminate parasitic emissions, and a coaxial connector for electrical connections, allowing for reduced dimensions while maintaining high voltage operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional X-ray tube designs are used with metal electrodes and dielectric insulators, then electrical insulation and field control are maintained, but the dimensions remain large (several hundred mm)
Solution Approach 1:
The patent changes the material parameter of the electrode from metal to dielectric, which fundamentally alters the electrical field distribution and eliminates the need for separate insulators. This parameter change enables miniaturization while maintaining electrical insulation reliability through the inherent properties of the dielectric material used for the electrode.
2Volume of moving object
If the radius of curvature of metal electrodes is reduced to minimize size, then compactness is improved, but parasitic electron emissions increase due to high electric fields
Solution Approach 1:
The patent changes the material parameter of the electrode from metal to dielectric, which fundamentally alters the electrical field distribution and eliminates the need for separate insulators. This parameter change enables miniaturization while maintaining electrical insulation reliability through the inherent properties of the dielectric material used for the electrode.
3Use of energy by moving object
If thermionic cathodes are used to emit electrons, then electron emission is achieved, but high operating temperatures cause expansion and evaporation problems
Solution Approach 1:
The patent replaces the thermionic emission mechanism (which relies on thermal energy) with field emission mechanism. The cold cathode uses strong electric fields to extract electrons directly from the material without heating, substituting a field-based mechanism for a thermal-based one. This eliminates temperature-related expansion and evaporation problems while maintaining electron emission capability.
4Reliability
If screens or increased distance are used to avoid surface charge phenomena on dielectric materials, then electrical stability is improved, but the dimensions of the X-ray tube increase
Solution Approach 1:
The patent changes the material parameter of the electrode from metal to dielectric, which fundamentally alters the electrical field distribution and eliminates the need for separate insulators. This parameter change enables miniaturization while maintaining electrical insulation reliability through the inherent properties of the dielectric material used for the electrode.
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 solution enables significant reduction in the size of X-ray sources while maintaining high electric field tolerance, overcoming the limitations of traditional X-ray tube designs and enabling miniaturization of ionizing radiation sources.
Implementation Method 1
a cathode configured to emit an electron beam in response to an applied voltage
Implementation Method 2
The radius of curvature of the metallic electrodes must not be too small in order to maintain a static electric field applied to the surface below an acceptable limit, typically 25 MV/m. Beyond that, the parasitic emissions of electrons by tunnel effect become difficult to control
Implementation Method 3
The electrons accelerated by the potential difference between the two electrodes produce a continuous spectrum of ionizing rays by braking (bremsstralung) when they strike the target
Data Source
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AI summary
The invention relates to a source for generating ionizing rays, and in particular X-rays, an assembly comprising a plurality of sources and a method for producing the source. The source comprises: · a vacuum chamber (12), · a cathode (14) that is able to emit an electron beam (18) into the chamber (12), · an anode (16) that receives the electron beam and that comprises a target (20) that is able to generate ionizing radiation (22) from the energy received from the electron beam (18), · an electrode (24) that is placed in the vicinity of the cathode (14) and that allows the electron beam 18 to be focused, · a stopper (32) ensuring the tightness of the vacuum chamber (12), · a mechanical part (28) made of dielectric material and forming a portion of the vacuum chamber; the stopper (32) is fastened to the mechanical part (28) by means of a conductive solder film (42) used to electrically connect the electrode (24).