Ion Source Conductive Sputtering Against Dielectric Deposit Buildup
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Solution Overview
Problem
The sensitivity of mass spectrometers degrades over time due to the buildup of dielectric deposits within the ion source, affecting sensitivity, mass resolution, mass accuracy, and ion abundance ratios.
Innovation Solution
A method is introduced to apply a conductive layer to the interior of the ion source by sputtering a conductive material, such as gold, onto the surfaces to form a conductive layer over any buildup of nonconductive material, thereby improving robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the ion source is used continuously for mass spectrometry analysis, then productivity is improved, but dielectric deposits accumulate on the ion source surfaces causing sensitivity degradation
Solution Approach 1:
A conductive layer is applied to the ion source surfaces before dielectric deposits can accumulate to problematic levels. This preliminary protective coating prevents sensitivity degradation during continuous operation, allowing the ion source to maintain performance over extended use without requiring frequent cleaning or replacement
2Productivity
If the ion source operates for extended periods, then productivity increases, but mass resolution and mass accuracy deteriorate due to dielectric deposit buildup
Solution Approach 1:
The conductive layer is applied in advance to prevent dielectric deposits from altering the electric field distribution in the ion source. By maintaining proper electric field conditions, the ion source preserves mass resolution and mass accuracy throughout extended operational periods
3Productivity
If the ion source is used without maintenance, then productivity is maintained, but ion abundance ratios become inaccurate due to dielectric deposits
Solution Approach 1:
The conductive layer is applied beforehand to prevent dielectric deposits from accumulating on surfaces where they would alter ion extraction and focusing. This maintains accurate ion abundance ratios throughout continuous operation without requiring intermediate maintenance
4Reliability
If a conductive layer is applied to the ion source interior, then sensitivity and robustness are improved, but device complexity increases
Solution Approach 1:
The surface electrical conductivity parameter of the ion source is modified by applying a conductive layer. This changes the electrical properties of the ion source surfaces to prevent dielectric deposit accumulation and maintain sensitivity, without fundamentally altering the overall ion source design or requiring complex additional components
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
The application of a conductive layer effectively addresses the issue of sensitivity degradation by maintaining or restoring the ion source's performance, ensuring consistent sensitivity, mass resolution, and accuracy over time.
Implementation Method 1
A method is introduced to apply a conductive layer to the interior of the ion source by sputtering a conductive material, such as gold, onto the surfaces
Data Source
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AI summary
A mass spectrometer system includes a vacuum manifold; an ion source positioned within the vacuum manifold for ionizing a sample; a mass analyzer for analyzing sample ions; a high vacuum pump connected to the vacuum manifold operable to maintain the pressure within the vacuum manifold at an operating pressure; and a controller configured to raise the pressure in the ion source to a sputtering pressure by supplying a flow of a sputtering gas and either reducing a speed of a high vacuum pump or isolating the ion source from the high vacuum pump; cause a conducting material to be sputtered on a surface of the ion source; and reduce the pressure in the ion source to an operating pressure by reducing the flow of the sputtering gas and either increasing the speed of the high vacuum pump or restoring connectivity between the ion source and the high vacuum pump.