Electron Beam Positioning Apparatus for X-ray Tube Stability
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Solution Overview
Problem
Conventional methods for positioning and focusing electron beams in X-ray tubes suffer from fluctuations in current flow due to high voltage pulses, leading to instability in the focal spot and reduced X-ray quality.
Innovation Solution
A positioning apparatus using two DC voltage circuits with different potential differences and a deflection module with switchable connections allows for a high voltage pulse to rapidly increase current and a lower voltage pulse to maintain it, minimizing fluctuations through pulse width modulation, and includes a full bridge configuration with semiconductor switches for controlled current management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a high voltage is applied to the deflection coil to achieve a high rate of rise in current, then the dynamics of positioning is improved, but current fluctuations increase leading to focal spot instability
Solution Approach 1:
The voltage supply is segmented into two distinct DC voltage circuits: a first circuit providing high voltage for rapid current rise during positioning transitions, and a second circuit providing low voltage for stable current maintenance during focal spot holding. This segmentation allows independent optimization of dynamics and stability for different operational phases.
Solution Approach 2:
The system dynamically switches between the two voltage circuits based on operational requirements. The switching mechanism enables the deflection coil to receive high voltage when rapid positioning is needed and low voltage when stability is prioritized, making the system adaptable to different operational states.
2Use of energy by moving object
If pulse width modulation is used to maintain current, then energy efficiency is improved, but current fluctuations occur due to high voltage pulsing
Solution Approach 1:
The PWM implementation is segmented into two modes corresponding to the two voltage circuits. High-voltage PWM pulses are used temporarily for positioning transitions, while low-voltage PWM is used for sustained current maintenance. This segmentation reduces the overall fluctuation impact while preserving energy efficiency.
Solution Approach 2:
The system changes the voltage parameter of the PWM circuit based on operational phase. By switching between high and low voltage levels, the system optimizes both energy efficiency and current stability, using high voltage only when necessary for positioning changes.
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 approach achieves a stable and dynamically positioned focal spot with reduced current fluctuations, enhancing the quality and precision of X-ray generation.
Implementation Method 1
The magnetic fields are generated by deflection coils, for example, which are arranged between the cathode and the anode around the electron beam or the X-ray tube
Implementation Method 2
In order to deflect the electron beam, but also to focus said electron beam, magnetic fields may be used
Implementation Method 3
The positioning apparatus further includes a deflection module having two inputs and at least one deflection coil... The first potential level of the first DC voltage circuit is connected switchably to an input of the deflection module
Implementation Method 4
As a result of energy conservation, the bremsstrahlung is emitted as a continuous spectrum on deceleration of the electrons in the anode material
Implementation Method 5
Furthermore, the electron beam ionizes atoms in the anode material, which results in transfers of fixed energy levels and, as a result, emission of the characteristic X-ray radiation takes place
Data Source
AI summary
A positioning apparatus is provided for an electron beam of an electron tube, the apparatus including a first DC voltage circuit having a high potential difference and a second DC voltage circuit having a smaller potential difference, having in each case a first potential level and a second potential level, and a deflection module, which has two inputs and at least one deflection coil, wherein the at least one deflection coil is connected between the two inputs of the deflection module.