Coaxial Ion Source Layout for Compact Cooling and Gas Supply

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Solution Overview

Problem

Existing ion sources for circular accelerators face challenges in achieving both cooling and gas supply to the electrical discharge chamber with a compact configuration due to independently disposed water cooling and gas tubes, leading to increased diameter and difficulty in miniaturization.

Innovation Solution

The ion source incorporates a coaxial structure with integrated cooling and gas supply flow paths, where the cooling tubes are positioned on the inner peripheral side of the gas supply flow path, reducing the need for separate insulation and allowing for a more compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If water cooling tube and gas supply tube are disposed independently, then cooling and gas supply functions are achieved, but the ion source diameter becomes large and the hole of the magnetic pole becomes large

Engineering Contradiction:
Improvecooling and gas supply functionVSAvoidion source diameter and magnetic pole hole size
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent combines the water cooling tube and gas supply tube into a single integrated tube structure. The cooling tube is positioned inside the gas supply tube, allowing both cooling and gas supply functions to be achieved through one bundled tube rather than two separate tubes. This merging reduces the overall diameter required for tube installation and reduces the magnetic pole hole size needed.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a nested configuration where the water cooling tube is placed inside the gas supply tube. This nested doll-like structure allows the cooling tube to be housed within the gas supply tube's interior space, maximizing space utilization and minimizing the external diameter of the tube bundle. This nesting approach directly addresses the need to reduce ion source and magnetic pole dimensions.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If independent tubes are used for cooling and gas supply, then both functions are provided, but the hole of the magnetic pole becomes large due to each required insulation distance

Engineering Contradiction:
Improveelectrical discharge preventionVSAvoidmagnetic pole hole size
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

By merging the cooling tube and gas supply tube into a single integrated structure, the patent reduces the number of separate insulation requirements. Instead of needing insulation between two independent tubes, the integrated design requires insulation only between the bundled tube assembly and the magnetic pole, significantly reducing the required insulation distance and magnetic pole hole size.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated tube structure serves multiple functions simultaneously - it provides both cooling and gas supply while requiring a single insulation barrier rather than multiple separate insulation layers. This multi-functionality approach consolidates the insulation requirement, reducing the overall space needed for insulation and the magnetic pole hole diameter.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If independent tubes are used for cooling and gas supply, then both functions are achieved, but manufacturability of the accelerator deteriorates

Engineering Contradiction:
Improvecooling and gas supply capabilityVSAvoidaccelerator manufacturability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the cooling and gas supply tube installations into a single bundled tube assembly that is inserted through one hole in the magnetic pole. This significantly simplifies the manufacturing process compared to installing two separate tubes through two separate holes, reducing assembly complexity and improving manufacturability while maintaining both cooling and gas supply functions.

Inventive Principle:
Principle #5Merging (Combining)

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 efficient cooling and gas supply to the electrical discharge chamber while minimizing the size of the ion source, facilitating the downsizing of the circular accelerator and improving manufacturability.

Implementation Method 1

a cooling flow path that cools the cathode support tool

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a cooling flow path that cools the cathode support tool

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

a gas supply flow path that supplies a gas to an electrical discharge chamber

Methodology Applied
Scientific EffectGas flow:

Implementation Method 4

The ion source is an apparatus that generates plasma therein and emits a part of the generated plasma from an emission port as a charged beam

Methodology Applied
Scientific EffectPlasma generation: Plasma

Implementation Method 5

an electrical discharge chamber formed by a space inside the anode

Methodology Applied
Scientific EffectElectrical discharge: Electric Arc

Data Source

PatentEP4697373A1Ion source, circular accelerator, and particle beam therapy system
Publication Date: 2026.02.18 HITACHI HIGH TECH CORP
  • EP4697373A1 patent drawingFigure 1
  • EP4697373A1 patent drawingFigure 2
  • EP4697373A1 patent drawingFigure 3

AI summary

A cathode 33, a cathode support tool 35 that supports the cathode 33 and applies and supplies a voltage, cooling tubes 24 and 25 that cool the cathode support tool 35, and a gas supply flow path 22, 22A, 22B, 22C, or 22D that supplies a gas to an electrical discharge chamber 36 are provided, and the cooling tubes 24 and 25 are disposed on a flow-path inner peripheral side of the gas supply flow path 22, 22A, 22B, 22C, or 22D. As a result, an ion source, a circular accelerator, and a particle beam therapy system that are capable of achieving both cooling and gas supply to an electrical discharge chamber with a compact configuration are provided.