RF LINAC Cavity Coating via Hall-Effect Magnetron Sputtering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High-power RF LINAC systems face challenges in compact design due to the need for additional hardware and complexity in coupling RF power, with existing solutions experiencing issues like multipactoring and high power dissipation when placing RF amplifier components within the vacuum environment.

Innovation Solution

A system that uses a magnetic array with Hall-Effect regions and an elongated sputtering electrode material tube to generate high-power pulsed plasma magnetron discharges for nanolayered coating on RF accelerator surfaces, allowing direct RF power injection into the LINAC cavity while keeping the RF power amplifier and circuitry outside the vacuum, utilizing a hermetic HV break and active cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If RF amplifier assembly is placed inside vacuum envelope, then direct RF power coupling is achieved, but multipactoring occurs and high power dissipation results

Engineering Contradiction:
ImproveRF power coupling structureVSAvoidmultipactoring resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent extracts the RF amplifier assembly from the vacuum envelope, placing it externally while maintaining direct RF power coupling through a hermetic feedthrough. This separation eliminates the multipactoring problem that occurs when RF amplifier components are inside the vacuum environment, while still achieving the benefit of direct power transfer to the cavity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a hermetic RF feedthrough as an intermediary component that enables direct RF power coupling between the external amplifier and the vacuum-sealed cavity. This mediator maintains the vacuum seal while allowing high-power RF signals to pass through, solving the contradiction between direct coupling and vacuum integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If RF amplifier is mounted outside vacuum, then multipactoring is reduced, but additional hardware and complexity are required

Engineering Contradiction:
Improvemultipactoring resistanceVSAvoidvacuum seal structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the RF feedthrough structure with the vacuum envelope, integrating the hermetic seal directly into the cavity housing. This merging eliminates the need for separate vacuum seal components, reducing overall device complexity while maintaining the benefit of placing the RF amplifier outside the vacuum environment.

Inventive Principle:
Principle #5Merging (Combining)

3Power

If high power is dissipated in antenna and anode, then active cooling is required, but system complexity and coolant selection constraints increase

Engineering Contradiction:
ImproveRF power handlingVSAvoidcooling system
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent extracts the high-power dissipation components (antenna and anode) from the vacuum environment and places them externally where conventional cooling systems can be applied. This separation allows the use of standard cooling techniques without the constraints of vacuum compatibility, reducing system complexity while maintaining high RF power handling capability.

Inventive Principle:
Principle #2Taking out (Extraction)

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 multipactoring effects, enables efficient RF power injection, and allows for easier maintenance without breaking the vacuum seal, while achieving higher accelerating gradients and lower RF power requirements, leading to a more compact and cost-effective high-power RF LINAC system.

Implementation Method 1

a magnetic array comprising multiple sets of magnets arranged to have Hall-Effect regions that run lengthwise along a sputter target

Methodology Applied
Scientific EffectHall-Effect: Hall Effect

Implementation Method 2

generating and controlling ion flux for direct current high-power impulse magnetron sputtering

Methodology Applied
Scientific EffectMagnetron sputtering: Sputtering

Implementation Method 3

generating a high-power pulsed plasma magnetron discharge with a high-current negative direct current (DC) pulse

Methodology Applied
Scientific EffectPlasma: Plasma

Data Source

PatentEP3896718A1System for depositing high-quality films on a three-dimensional surface of an accelerator cavity and method thereof
Publication Date: 2021.10.20 STARFIRE IND LLC
  • EP3896718A1 patent drawingFigure 1
  • EP3896718A1 patent drawingFigure 2A
  • EP3896718A1 patent drawingFigure 2B

AI summary

A system and associated method are described for depositing high-quality films for providing a nanolayered coating on a three-dimensional surface. The system includes a magnetic array comprising multiple sets of magnets arranged to have Hall-Effect regions that run lengthwise along a sputter target. The system further includes an elongated sputtering electrode material tube surrounding the magnetic array comprising multiple sets of magnets arranged to have Hall-Effect regions that run lengthwise along the sputter target. During operation, the system generates and controls ion flux for direct current high-power impulse magnetron sputtering. During operation logic circuitry issues a control signal to control a kick pulse property of a sustained positive voltage kick pulse taken from the group consisting of: onset delay, amplitude and duration.