Multi-beam Klystron Pole Piece Magnetic Circuit Separation

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Solution Overview

Problem

In multi-beam klystron apparatuses, increasing axial magnetic flux density near the output cavity to prevent electron beam spread causes curvature of electron beams, making stable operation impossible, and reducing flux density in this area leads to beam dispersion.

Innovation Solution

A radio-frequency interaction unit pole piece is arranged between the output magnetic field generator and the main magnetic field generator to separate the magnetic circuit near the output cavity, allowing for increased axial magnetic flux density without curving the electron beams.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the axial magnetic flux density is increased near the output cavity to prevent electron beam spread, then the electron beam focus is improved, but the electron beams curve and stable operation becomes impossible

Engineering Contradiction:
Improveelectron beam focusVSAvoidstable operation
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The magnetic field generation is segmented into two independent systems: a main magnetic field generator that provides the overall focusing field, and an output magnetic field generator that specifically addresses beam spread near the output cavity. This segmentation allows each system to be optimized independently, enabling high magnetic flux density near the output without causing beam curvature that would result from a uniform increase in the main field.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies local quality by creating a non-uniform magnetic field distribution where the axial magnetic flux density is specifically increased only in the region near the output cavity, while the main magnetic field remains relatively uniform elsewhere. This localized enhancement prevents beam spread at the critical output region without causing the beam curvature that would occur with a global increase in magnetic flux density.

Inventive Principle:
Principle #3Local quality

2Reliability

If the axial magnetic flux density is reduced near the output cavity to maintain parallel magnetic field lines, then stable operation is maintained, but electron beam dispersion occurs

Engineering Contradiction:
Improvestable operationVSAvoidelectron beam focus
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

By dividing the magnetic field generation into separate main and output field generators, the system can maintain stable overall operation with the main field while independently enhancing the output region field to prevent beam dispersion, thereby resolving the contradiction between stability and focus.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The local quality principle allows the magnetic field to have different characteristics in different regions: a stable, relatively uniform main field for overall beam control, and a locally enhanced field near the output cavity to prevent beam dispersion, achieving both stability and focus simultaneously.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If the radius of the drift tube is increased to prevent electron beam collision, then beam spread is suppressed, but output conversion efficiency is reduced

Engineering Contradiction:
Improvebeam spread suppressionVSAvoidoutput conversion efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention replaces the mechanical approach of increasing drift tube radius with a magnetic field-based approach using an output magnetic field generator. This substitution allows beam spread suppression through magnetic focusing rather than physical constraints, maintaining the drift tube's compact size and preserving output conversion efficiency while still preventing beam collision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 configuration enables the axial magnetic flux density to be increased near the output cavity without curving the electron beams, effectively preventing their spread and ensuring stable operation by maintaining parallel magnetic field lines.

Implementation Method 1

an output magnetic field generator (44) arranged on the outside of the output cavity (36)

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

a main magnetic field generator (40) arranged around the input cavity (31) and a plurality of intermediate cavities (32 to 35)

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 3

an electron beam, in the absence of radio frequency, has a substantially constant thickness

Methodology Applied
Scientific EffectElectron beam: Electron Beam

Implementation Method 4

a radio-frequency interaction unit for amplifying the radio-frequency power by the interaction between the electron beam and the radio-frequency electric field

Methodology Applied
Scientific EffectRadio-frequency electric field: Electric Field

Data Source

PatentEP1793407B1Multi-beam klystron apparatus
Publication Date: 2011.07.13 KK TOSHIBA
  • EP1793407B1 patent drawingFigure 1
  • EP1793407B1 patent drawingFigure 2
  • EP1793407B1 patent drawingFigure 3

AI summary

A multi-beam klystron apparatus (11) is disclosed. A radio-frequency interaction unit pole piece (52) is arranged between a main magnetic field generator (40) and an output-side magnetic field generator (44). The magnetic circuit formed in the neighborhood of an output cavity (36) of a radio-frequency interaction unit (19) is separated from the magnetic circuit of the main magnetic field generator (40) by the radio-frequency interaction unit pole piece (52). The output-side magnetic field generator (44) increases the axial magnetic flux density in the neighborhood of the output cavity (36) without curving the electron beams and thus prevents the spread of the electron beams in the neighborhood of the output cavity (36).