Accelerating Structure Choke Vacuum Port

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In accelerating structures longer than 2 meters, the middle part often fails to be fully evacuated due to incomplete vacuuming, and providing evacuation holes on the side surfaces allows alternating electric fields to leak, preventing efficient confinement.

Innovation Solution

The accelerating structure incorporates a choke structure with through-holes on the outer circumference of discs, allowing for efficient evacuation from the middle part without leaking the alternating electric field, ensuring a high degree of vacuum and maintaining field confinement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a through-hole for evacuation is provided on the side surface of the accelerating structure, then the middle part can be evacuated more effectively, but the alternating electric field leaks from the through-hole

Engineering Contradiction:
Improvevacuum qualityVSAvoidelectric field confinement
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The choke structure serves as an intermediary element between the through-hole and the accelerating structure cavity. It allows gas molecules to pass through for evacuation while blocking the alternating electric field from leaking out. The choke structure achieves this by creating a narrow passage that permits molecular flow of gas but prevents electromagnetic field propagation, thus resolving the contradiction between evacuation effectiveness and field confinement.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the accelerating structure is made long to achieve higher particle energy, then particle acceleration performance improves, but the middle part fails to be fully evacuated

Engineering Contradiction:
Improveparticle acceleration capabilityVSAvoidvacuum quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention segments the evacuation function by adding intermediate evacuation openings at strategic positions along the accelerating structure, rather than relying solely on end evacuation. This segmentation allows different regions of the long accelerating structure to be evacuated independently, ensuring that the middle parts are also fully evacuated while maintaining the length required for high particle energy.

Inventive Principle:
Principle #1Segmentation

3Productivity

If evacuation openings are added to the side surfaces of discs, then evacuation efficiency improves, but the alternating electric field is no longer confined

Engineering Contradiction:
Improveevacuation efficiencyVSAvoidelectric field leakage
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The choke structure introduces local quality variation at the evacuation openings. Instead of having uniform properties throughout the disc, the choke structure creates a localized region with specific geometric characteristics (narrow passage) that selectively permits gas flow while blocking electric field leakage. This local modification allows side surface openings to be used for evacuation without compromising field confinement.

Inventive Principle:
Principle #3Local quality

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 full evacuation of the middle part while maintaining the alternating electric field inside, enhancing vacuum quality and allowing operation in high electric fields.

Implementation Method 1

The accelerating structure is formed of a plurality of annular discs serially connected into a cylindrical shape and having a central through-hole formed in the direction of an axis for beam passage. The annular discs are moreover provided with a choke structure to prevent leaking of high frequency power

Methodology Applied
Scientific EffectChoke mode:

Implementation Method 2

an exhaust device is attached to the coupler cells provided at the both ends of the accelerating structure to evacuate the accelerating structure

Methodology Applied
Scientific EffectVacuum evacuation: Vacuum

Implementation Method 3

an accelerating structure which internally accelerates particles such as electrons, positrons, and protons

Methodology Applied
Scientific EffectElectromagnetic acceleration: Electromagnetic Induction

Data Source

PatentEP2731409B1Accelerating structure
Publication Date: 2016.11.30 MITSUBISHI HEAVY IND MACHINERY SYST LTD
  • EP2731409B1 patent drawingFigure 1
  • EP2731409B1 patent drawingFigure 2
  • EP2731409B1 patent drawingFigure 3

AI summary

The present invention provides an accelerating structure capable of increasing a degree of vacuum at a middle part inside the accelerating structure while confining an alternating electric field to the inside. An accelerating structure 1 is formed of a plurality of annular discs 2 and 3 serially connected into a cylindrical shape. At least one of the discs 3 disposed at a middle part of the accelerating structure 1 includes: a choke structure formed by a choke filter 7; and a vacuum port 8 opened in an outer circumferential surface of the disc further on an outer circumferential side than the choke structure, and the vacuum port 8 is connected to an external exhaust device.