Ion Accelerator Shielding Surface Erosion Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The surface surrounding the exit opening of ion accelerator arrangements in spacecraft is prone to erosion due to the impact of ions from the ejected plasma jet, which can be severe and difficult to repair, especially in environments with high-energy cosmic radiation.

Innovation Solution

A magnetic field with a direction predominantly parallel to the surface section, combined with an electrically non-conductive or insulated shielding surface at a potential separate from the spacecraft's ground potential, effectively reduces ion impact by creating an electric field that repels further ions and deflects electrons, thereby minimizing erosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a magnetic field with direction predominantly parallel to the surface section is introduced, then electron impact on the surface is reduced, but the device complexity increases

Engineering Contradiction:
Improveelectron impact on surfaceVSAvoidmagnetic field generation system
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The magnetic field acts as an intermediary between the plasma jet and the surface section, deflecting electrons away from the surface before they can cause damage. The field mediates the interaction by introducing a third element (magnetic influence) that alters the trajectory of charged particles without direct physical contact.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces potential mechanical shielding structures with a magnetic field-based solution. Instead of using physical barriers or absorptive materials to protect the surface, the invention uses electromagnetic forces to deflect electrons, substituting a mechanical approach with a field-based approach.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Object-affected harmful factors

If the surface section is made electrically non-conductive or insulated, then positive charging is retained and ion repulsion is enhanced, but the ease of manufacture decreases

Engineering Contradiction:
Improveion impact on surfaceVSAvoidsurface section fabrication
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent changes the electrical parameter of the surface section from conductive to non-conductive or insulated. This parameter change allows the surface to retain positive charging capability, which in turn enables electrostatic repulsion of ions. The modification involves altering the electrical conductivity property rather than the physical structure.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

By making the surface section electrically isolated, the patent creates an equipotential region that can maintain a stable positive charge. This isolated electrical state allows the surface to repel ions effectively without being short-circuited to the spacecraft body, maintaining the repulsive electric field.

Inventive Principle:
Principle #12Equipotentiality

3Object-affected harmful factors

If the magnetic field deflects electrons away from the surface, then electron-induced damage is reduced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveelectron damage to surfaceVSAvoidmagnetic field alignment
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The magnetic field is configured to have local quality variations, with field strength and direction optimized specifically in the region near the surface section. The field is not uniformly distributed but rather tailored to provide maximum electron deflection precisely where needed, while allowing more flexibility in other regions.

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 significantly reduces surface erosion by repelling positively charged ions and deflecting electrons, maintaining a repelling electric field and preventing electron impact on the shielding surface, thus protecting the spacecraft from plasma jet-induced damage.

Implementation Method 1

electrons which are accelerated by such a field in the direction of the surface section, due to their low mass and high speed are deflected in the magnetic field and kept away from the surface section

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Implementation Method 2

a positive charging of the surface section resulting from an initial exposure of the surface section to ions leads to an electric field that repels further ions

Methodology Applied
Scientific EffectElectric field repulsion: Electric Field

Data Source

PatentEP2193272B1Ion accelerator arrangement comprising a device for reducing the impact of positively charged ions on a surface section
Publication Date: 2018.03.28 THALES ELECTRONICS SYST
  • EP2193272B1 patent drawingFigure 1~2

AI summary

The invention relates to a surface section that is exposed to an ion flow, in particular for a drive arrangement in a spacecraft, comprising an electrostatic ion accelerator arrangement. According to the invention, in order to reduce erosion, an intermediate potential energy surface is provided, said surface being advantageous in that it allows a magnetic field that is essentially parallel to the surface section to be formed.