Cyclotron RF Resonator Asymmetrical Fixed Tuner Design

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Solution Overview

Problem

Traditional cyclotron resonators require complex control software and numerous moving parts to maintain symmetry, increasing design complexity, maintenance costs, and the risk of failure, especially when both tuners need to be moved for optimal performance.

Innovation Solution

The implementation of an asymmetrical fixed tuner system within a cyclotron RF resonator, where a single shorting plate tuner is used inside a moveable tuner stem and a fixed short is integrated, eliminating the need for top-bottom mirror symmetry and reducing the number of moving parts, thereby simplifying the design and control requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If symmetrical tuners are used in a cyclotron resonator to maintain field balance and cavity eigenmode matching, then acceleration performance is improved, but device complexity and the number of moving parts increase significantly

Engineering Contradiction:
Improveacceleration performanceVSAvoidcomplexity of cyclotron
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by using a fixed tuner instead of symmetrical movable tuners. The fixed tuner is positioned at a specific location (e.g., at the Dee center or at a radius where the beam does not pass) and remains stationary, eliminating the need for complex movable mechanisms while still achieving the required field balance and cavity eigenmode matching for optimal acceleration performance.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent segments the tuning function by separating the tuner into a fixed structure rather than requiring coordinated movement of multiple symmetrical components. This segmentation allows the resonator to achieve proper tuning through a single fixed element, reducing the overall system complexity while maintaining the necessary field balance.

Inventive Principle:
Principle #1Segmentation

2Reliability

If multiple movable parts are used to maintain symmetry in cyclotron tuners, then field balance is preserved, but reliability decreases due to increased risk of failure

Engineering Contradiction:
Improverisk of failureVSAvoidnumber of moving parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the tuning function to be performed by a single fixed tuner rather than multiple movable components. This segmentation eliminates the need for coordinated movement and reduces the number of moving parts, thereby increasing reliability by removing potential failure points associated with mechanical movement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using movable tuners that need to be precisely positioned and maintained, the patent inverts the approach by using a fixed tuner. This inversion eliminates the mechanical complexity and reliability issues associated with movable parts while still achieving the required tuning and field balance.

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of operation

If symmetrical tuners are implemented in a cyclotron, then cavity eigenmode matching is achieved, but control software complexity increases

Engineering Contradiction:
Improvecontrol software complexityVSAvoidcontrol software complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent segments the tuning control by using a fixed tuner that requires no active control or coordination. This eliminates the need for complex control software that would be required to manage the synchronized movement of multiple symmetrical tuners, while still achieving proper cavity eigenmode matching through the strategically positioned fixed tuner.

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 reduces design complexity, maintenance costs, and software complexity while maintaining high acceleration performance by binding the maximum acceleration voltage to the capacitance of the accelerating surfaces, thus enabling efficient particle acceleration with fewer moving parts and simplified control systems.

Implementation Method 1

R. Smythe, 'A fractional turn injector cyclotron', Proceedings of the Fifth International Cyclotron conference, pages 95-100, discloses a traditional cyclotron RF resonator tuned by moving a shorting plane along a coaxial line.

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 2

A RF resonator is used to produce a voltage to accelerate particles.

Methodology Applied
Scientific EffectElectromagnetic acceleration: Electromagnetic Induction

Data Source

PatentEP3549410B1Cyclotron RF resonator with asymmetrical tuning
Publication Date: 2021.04.21 VARIAN MEDICAL SYST PARTICLE THERAPY GMBH & CO KG
  • EP3549410B1 patent drawingFigure 1
  • EP3549410B1 patent drawingFigure 2
  • EP3549410B1 patent drawingFigure 3

AI summary

Embodiments of the present invention disclose methods and systems for performing particle acceleration using a cyclotron RF resonator with an asymmetrical fixed tuner. A cyclotron RF resonator includes a single shorting plate tuner inside and a fixed short stem, and does not require top-bottom mirror symmetry. Small movements in relation to the wavelengths of the maximum acceleration voltage is bound by the capacitance of the accelerating surfaces. As such, the resonator may perform particle acceleration using asymmetrical tuning to reduce design complexity, cost of maintenance, fabrication and installation complexity, failure rate, and software complexity (e.g., control software), for example.