Vacuum Chamber Segmentation for Plasma Thruster Testing
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Solution Overview
Problem
Conventional test systems for plasma reaction thrusters in vacuum chambers face issues with electrical interference and higher gas density, which affect the natural evolution of the thruster beam, especially at higher power levels, due to the conductive nature of the vacuum chamber and ground connection, leading to inefficient and costly testing.
Innovation Solution
Applying an electrical bias voltage to the plasma beam to electrically isolate electrons from conductive walls and grounded equipment, using an electrode to attract electrons downstream, thereby simulating the space environment and reducing radial electron flow to the chamber walls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the vacuum chamber is connected to earth ground to provide electrical stability, then electrical safety and stability are improved, but electrical interference with the plasma beam increases and testing accuracy deteriorates
Solution Approach 1:
The vacuum chamber is divided into two electrically isolated sections: a grounded section and an isolated section containing the plasma source. This segmentation allows the chamber to be grounded for safety while the plasma region remains electrically isolated to prevent interference with the beam, resolving the contradiction between electrical stability and testing accuracy.
Solution Approach 2:
An electrical isolation barrier (such as an insulating flange or dielectric material) is introduced between the grounded vacuum chamber and the plasma source region. This intermediary element blocks electrical interference from reaching the plasma beam while maintaining the grounded connection for safety, thus preserving both electrical stability and beam accuracy.
2Measurement precision
If the vacuum chamber maintains a low vacuum level to simulate space environment, then environmental accuracy is improved, but gas density remains higher than space conditions and electron loss to walls increases
Solution Approach 1:
The isolated vacuum chamber section is maintained at a floating or controlled electrical potential that prevents electrons from being attracted to the chamber walls. By making the chamber walls equipotential with the plasma or providing electrical isolation, electron loss to walls is minimized while maintaining the vacuum environment for accurate space simulation.
3Ease of manufacture
If conventional test systems use grounded conductive walls to simplify construction, then ease of manufacture is improved, but electrical interference with plasma beam evolution increases and testing cost increases
Solution Approach 1:
The vacuum chamber is segmented into grounded and isolated sections, allowing the majority of the chamber structure to remain simple and grounded for ease of manufacture, while the plasma interaction region is isolated to preserve beam evolution accuracy. This segmentation balances manufacturing simplicity with testing precision.
4Reliability
If the vacuum chamber is grounded to prevent electrical hazards, then safety is improved, but electrical discharge and interference with plasma operations increase
Solution Approach 1:
The electrical ground connection is extracted or removed from the plasma source region and confined to separate sections of the vacuum chamber. This allows the plasma region to operate without direct ground connection, preventing electrical discharge and interference, while other parts of the chamber remain grounded for safety.
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 effectively isolates electrons, allowing them to travel in the same direction as ions, reducing electrical interference and simulating the low-density environment, thus improving the accuracy and reducing the costs associated with maintaining a low vacuum level during testing.
Implementation Method 1
Applying an electrical bias voltage to the plasma beam to electrically isolate electrons from conductive walls and grounded equipment
Implementation Method 2
using an electrode to attract electrons downstream
Data Source
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AI summary
System (300, 400) and methods (500) for testing a reaction thruster (100) in a vacuum environment. The methods comprise: disposing the reaction thruster in a vacuum chamber which is at least partially connected to earth ground; removing at least one gas from the vacuum chamber to provide the vacuum environment; operating the reaction thruster so as to create a beam of electrons; and/or electrically isolating the electrons of the beam from at least one electrically conductive surface of the vacuum chamber. The electrical isolation can be achieved by applying an electrical bias voltage to the beam via an electrode. The electrode may comprise a conductive object disposed in the vacuum chamber and/or at least a portion of a vacuum chamber wall. In all cases, the electrode is electrically isolated from a portion of the vacuum chamber that is connected to ground.