Electron Optics Ionization Source for High-Pressure Filament Protection
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Solution Overview
Problem
Ionization devices face filament degradation and reduced lifetime when operating at high pressures, especially with semiconducting matrix gases like hydrogen and halogens, due to chemical reactions with the metallic filament material, leading to inefficient ionization.
Innovation Solution
The implementation of an electron optics system with multiple electrodes to focus and control the electron beam, measure emission current, and deflect the beam, combined with a vacuum generation device to maintain low filament pressure, effectively reduces filament degradation and extends its lifetime by diluting the gas stream and preventing reactive sputtering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electron ionization is performed at high pressures, then ionization efficiency is improved, but filament lifetime is reduced due to chemical reactions and reactive sputtering
Solution Approach 1:
The ionization device is divided into two distinct pressure regions: a high-pressure ionization space (0.001-1 mbar) for efficient ionization and a low-pressure filament region (10^-6 to 10^-3 mbar) protected by a vacuum generation device. This segmentation allows the filament to operate in a protected environment while the ionization space maintains high pressure for efficient ionization of gases containing S/C matrix gases.
Solution Approach 2:
A vacuum generation device acts as an intermediary between the high-pressure ionization space and the filament, creating a pressure gradient that protects the filament from direct exposure to reactive matrix gas ions while still allowing efficient ionization to occur in the ionization space.
2Reliability
If pressure in ionization space is increased, then ionization of S/C matrix gases is improved, but reactive sputtering of filament increases
Solution Approach 1:
The device segments the system into a high-pressure ionization space for reliable ionization of S/C matrix gases and a low-pressure filament region protected by vacuum generation, preventing reactive sputtering while maintaining ionization performance.
Solution Approach 2:
The vacuum generation device serves as an intermediary that creates a protective pressure barrier, allowing the filament to be shielded from harmful reactive sputtering effects while the ionization space maintains the pressure needed for effective ionization of challenging gases.
3Productivity
If filament is exposed to high pressure gas stream, then ionization efficiency is improved, but chemical reactions with matrix gases increase
Solution Approach 1:
The system is segmented into a high-pressure ionization space where efficient ionization occurs and a low-pressure filament region where material loss is minimized through vacuum protection, resolving the contradiction between ionization efficiency and filament material preservation.
Solution Approach 2:
The vacuum generation device acts as an intermediary that creates a protective environment for the filament, preventing direct chemical reactions with matrix gases while allowing the ionization space to operate at high pressure for efficient ionization.
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 solution enables efficient ionization of gases at high pressures while significantly increasing the filament's operational lifetime by minimizing chemical reactions and maintaining a stable emission current, allowing for continuous operation without the need for pressure reduction stages.
Implementation Method 1
Electron ionization uses an electron source having a filament (heating wire) for the ionization, in order, by means of the thermionic effect, to generate an electron beam that strikes the gas to be ionized and ionizes it.
Implementation Method 2
generate an electron beam that strikes the gas to be ionized and ionizes it
Implementation Method 3
a vacuum generation device configured to generate a pressure at the filament of the electron source which is lower than a pressure in the ionization space
Data Source
AI summary
The invention relates to an ionization device with an ionization space formed in a container, an inlet system for supplying a gas to be ionized to the ionization space, an electron source having at least one filament for supply of an electron beam to the ionization space, and an outlet system for letting the ionized gas out of the ionization space. Electron optics having at least two electrodes are disposed between the filament and the ionization space.