Input Coupler Thermal Insulation for Accelerator Cavity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In superconducting accelerator systems, the input coupler's double window structure poses challenges in preventing heat transfer from the internal conductor to the external conductor, particularly when using water as a heating medium, which can freeze at low temperatures, leading to inefficient cooling during high radio frequency power operations.

Innovation Solution

The input coupler incorporates a heat insulating part with lower thermal conductivity than the internal conductor, reducing heat transfer between the internal conductor and a ceramic plate, and includes a vacuum insulation structure and a bellows to prevent deflection due to thermal expansion, while maintaining a double window structure for vacuum sealing and contamination prevention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If water is used as a heating medium in the internal conductor to cool it during high radio frequency power operations, then cooling efficiency is improved, but water freezes at low temperatures causing cooling failure

Engineering Contradiction:
Improvecooling efficiencyVSAvoidcooling system reliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

A heat insulating part made of material with lower thermal conductivity than the internal conductor is introduced as an intermediary between the internal conductor and the ceramic plate. This mediator reduces heat transfer from the internal conductor to the plate, preventing the internal conductor temperature from dropping to water's freezing point while maintaining effective cooling during high radio frequency power operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The heat insulating part is strategically positioned only at the connection portion between the internal conductor and the ceramic plate, providing localized thermal insulation where needed. This allows the internal conductor to maintain adequate temperature for water-based cooling while still enabling the ceramic plate to be cooled to low temperatures for its operational requirements.

Inventive Principle:
Principle #3Local quality

2Device complexity

If a single window structure is used in the input coupler, then device complexity is reduced, but vacuum sealing reliability and contamination prevention are compromised

Engineering Contradiction:
Improvewindow structure complexityVSAvoidvacuum sealing reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The single window structure is segmented into a double window configuration, with a first ceramic plate and a second ceramic plate positioned at different locations in the input coupler. This segmentation provides multiple vacuum sealing barriers, enhancing vacuum sealing reliability and preventing contamination from reaching the accelerating cavity even if one window fails.

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 configuration prevents the internal conductor from cooling to the freezing point of water or lower, reduces heat transfer to the external conductor, and enables efficient cooling even during high radio frequency power operations, thereby enhancing the cooling performance of the input coupler.

Implementation Method 1

a heat insulating part with lower thermal conductivity than the internal conductor, reducing heat transfer between the internal conductor and a ceramic plate

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

includes a vacuum insulation structure

Methodology Applied
Scientific EffectVacuum insulation: Vacuum

Implementation Method 3

includes a bellows to prevent deflection due to thermal expansion

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 4

a cooling part for cooling the plate from the external conductor side

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3413692B1Input coupler for acceleration cavity, and accelerator
Publication Date: 2021.03.31 MITSUBISHI HEAVY IND MACHINERY SYST LTD
  • EP3413692B1 patent drawingFigure 1
  • EP3413692B1 patent drawingFigure 2
  • EP3413692B1 patent drawingFigure 3

AI summary

An input coupler for an accelerating cavity (1) includes a cylindrical external conductor (2); a cylindrical internal conductor (3) arranged coaxially with the external conductor (2), inside of which a heating medium circulates; a plate (4) provided between the inner surface of the external conductor (2) and the outer surface of the internal conductor (3); a cooling part (9) for cooling the plate (4) from the external conductor (2) side to the freezing point of water or lower; and a heat insulating part (8) provided on the part at which the internal conductor (3) and the plate (4) are connected, the heat insulating part (8) having lower thermal conductivity than that of the internal conductor (3). The plate (4) is connected to the internal conductor (3) via the heat insulating part (8).