Nested MICD Electron Beams With Different Energies From One Cathode

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current technologies face challenges in generating multiple electron beams with different energies and comparable currents from a single cathode stalk at a single potential, particularly in high-power microwave sources, where increasing voltage or current leads to inefficiencies and complex power supply requirements.

Innovation Solution

The use of nested magnetically insulated coaxial diodes (MICDs) connected to a single cathode stalk, where two electron beams are generated with an energy difference of 5-30% and comparable currents, utilizing a pulsed power generator to apply a voltage of 100 kV to 500 kV, and particle-in-cell (PIC) simulations are performed to optimize the geometry for maximum energy difference and current similarity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If separate power supplies are used to power multiple cathodes at different voltages, then multiple electron beams with different energies can be generated, but the device complexity and power supply requirements increase significantly

Engineering Contradiction:

Improveelectron beam energyVSAvoidpower supply complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent combines multiple cathodes (inner cathode and outer cathode) onto a single cathode stalk, which is powered by a single pulsed power generator. This merging approach allows multiple electron beams with different energies to be generated while eliminating the need for multiple separate power supplies, thus reducing device complexity while maintaining energy differentiation capability

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent employs a nested configuration where the inner cathode is positioned inside the outer cathode, both attached to the same cathode stalk. This nested structure enables space-efficient arrangement of multiple cathodes that share a common power supply connection, allowing independent control of beam parameters through geometric configuration rather than separate power supplies

Inventive Principle:

Principle #7Nested doll (Nesting)

2Power

If the electron beam current is increased to generate more power, then the power output increases, but the space charge increases making confinement more challenging

Engineering Contradiction:

Improvepower outputVSAvoidbeam confinement complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The patent segments the total beam current into multiple separate electron beams (inner beam and outer beam) that travel through distinct vacuum channels. By dividing the high-current single beam into multiple lower-current beams, the space charge density in each channel is reduced, making confinement easier while the total power output remains high due to the combined current of all beams

Inventive Principle:

Principle #1Segmentation

3Power

If the applied voltage is increased to generate more power, then the power output increases, but the vacuum channel size and power supply complexity increase

Engineering Contradiction:

Improvepower outputVSAvoidvacuum channel size

Core Design Contradiction:

PowerVSLength of stationary object

Solution Approach 1:

The patent segments the voltage application by creating multiple cathodes at different radial positions (inner and outer cathodes) that experience different effective accelerating potentials. This allows generation of multiple beams with different energies from a single power supply, achieving power multiplication without requiring a single extremely high-voltage channel

Inventive Principle:

Principle #1Segmentation

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 allows for the generation of multi-stream electron beams with 6-27% energy difference and comparable currents, enhancing the efficiency of high-power microwave sources and validating theoretical and simulation results through experimental validation, demonstrating potential for super-amplification in traveling wave tubes (TWTs).

Implementation Method 1

driving the cathode stalk with a pulsed power generator at a single potential, producing a first electron beam from the inner cathode, and producing a second electron beam from the outer cathode

Methodology Applied

Scientific EffectThermionic emission: Thermionic Emission

Implementation Method 2

nested magnetically insulated coaxial diodes (MICDs)

Methodology Applied

Scientific EffectMagnetic insulation: Magnetic Field

Data Source

PatentUS20230420212A1Technique for multi-stream electron beam generation with different energies and comparable currents from a single cathode potential for high power microwave sources

Publication Date: 2023.12.28 UNM RAINFOREST INNOVATIONS

AI summary

A method for generating multi-stream electron beams is disclosed, the method including connecting an inner cathode to a cathode stalk, connecting an outer cathode to the cathode stalk, driving the cathode stalk with a pulsed power generator at a single potential, producing a first electron beam from the inner cathode, and producing a second electron beam from the outer cathode. Implementations of the method for generating multi-stream electron beams may include where each of the inner cathode and the outer cathode may include nested magnetically insulated coaxial diodes (MICDs). The first electron beam and the second electron beam can be generated with different energies. A multi-stream traveling wave tube (TWT) and an electron beam generating apparatus are also described.