Grid-Controlled Electron Beam Cathode for Fast Spot Size Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electron beam sources face a tradeoff between high power and low intensity, limiting their effectiveness in additive manufacturing, particularly in achieving large electron beam currents and high beam intensity for different applications.
Innovation Solution
An electron beam source design with a cathode featuring a base and protrusion, allowing for adjustable spot sizes by varying the grid voltage, enabling high power and low intensity electron beams using the same beam shaping optics settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the emission area of the cathode is increased to achieve high power, then the maximum power of the electron beam is improved, but the beam intensity deteriorates in the low current regime
Solution Approach 1:
The cathode is segmented into two distinct emission surfaces: a top surface with smaller area for high intensity emission, and a base surface with larger area for high power emission. This segmentation allows the system to switch between different operational modes by controlling which surface emits electrons, resolving the contradiction between maximizing power and maintaining intensity.
Solution Approach 2:
The system dynamically switches between different cathode emission surfaces based on operational requirements. By controlling the potential distribution, the system can activate either the top surface alone (for high intensity) or both surfaces simultaneously (for high power), making the emission characteristics adaptable rather than fixed.
2Adaptability or versatility
If different spot sizes are achieved by changing beam shaping optics settings, then the electron beam can be adapted for different applications, but the switching time and complexity increase
Solution Approach 1:
Different emission configurations are prepared in advance by maintaining both top and base surfaces as active emission areas with pre-established electrical connections. The system only needs to switch potential distribution to change spot size, avoiding the time-consuming process of physically adjusting optics settings or replacing components.
Solution Approach 2:
The system changes the electrical parameter (potential distribution) to switch between different emission modes. By adjusting which cathode surfaces are at what potential, the system can rapidly change the effective emission area and resulting spot size without physical adjustments, reducing switching time while maintaining versatility.
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
Facilitates rapid switching between spot sizes during manufacturing without altering optics settings, enhancing the versatility and efficiency of electron beam usage in additive manufacturing processes.
Implementation Method 1
a cathode, an anode and a grid for regulating an electron beam current
Data Source
AI summary
Provided is an electron beam source for generating an electron beam comprising a cathode, an anode and a grid for regulating an electron beam current. The cathode has a base and a protrusion with sidewalls and a top surface. The base surface and the top surface are essentially flat. The base surface and the top surface are arranged at a predetermined distance from each other. The base is larger than the protrusion. The electron beam source further comprising a control unit adapted for changing an applied voltage to the grid for switching a spot size of the electron beam on a target surface between at least a first a first spot size corresponding to emission from the top surface of the cathode only and to a second spot size corresponding to emission from the top surface and the base surface of the cathode.