Tapered RF Ion Guide for Low-Loss Ion Transport
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Solution Overview
Problem
In mass spectrometry, ion losses occur during the transportation of ions through ion guides, leading to reduced transport efficiency and sensitivity.
Innovation Solution
A mass spectrometer apparatus with an ion guide having tapered electrodes and a smaller exit end diameter, which applies an RF voltage to radially confine and focus ions, reducing gas conductance at the exit end to minimize ion loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the ion guide has a constant diameter throughout its length, then the structure is simple and easy to manufacture, but ion losses occur during transportation reducing transport efficiency
Solution Approach 1:
The ion guide employs a tapered structure where the diameter varies along its length, with the entrance end having a larger diameter than the exit end. This local variation in geometry creates different gas conductance characteristics at different positions, reducing ion losses at the exit aperture while maintaining structural feasibility through a gradual transition.
2Productivity
If the ion guide has a larger exit end diameter, then ion transport efficiency is improved, but gas conductance increases causing more ion loss
Solution Approach 1:
The ion guide employs a tapered structure where the diameter varies along its length, with the entrance end having a larger diameter than the exit end. This local variation in geometry creates different gas conductance characteristics at different positions, reducing ion losses at the exit aperture while maintaining structural feasibility through a gradual transition.
3Loss of substance
If the ion guide has a smaller exit end diameter, then ion loss is reduced, but gas conductance decreases creating resistance to ion flow
Solution Approach 1:
The ion guide employs a tapered structure where the diameter varies along its length, with the entrance end having a larger diameter than the exit end. This local variation in geometry creates different gas conductance characteristics at different positions, reducing ion losses at the exit aperture while maintaining structural feasibility through a gradual transition.
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 solution enhances ion transport efficiency and sensitivity by reducing ion losses during transportation through the ion guide, allowing for higher sensitivity in mass analysis.
Implementation Method 1
when an RF voltage, provided by an RF power supply, is applied to the at least one ion guide, the ions are radially confined within the internal volume of the at least one ion guide and focused and directed to the exit aperture
Implementation Method 2
a radio frequency signal can be applied to the ion guide to provide radial focusing of ions within the ion guide
Implementation Method 3
there is a greater resistance to the radial flow of gas from the interior to the exterior of the ion guide at the exit end than at the entrance end
Implementation Method 4
greater resistance to the radial flow of gas from the interior to the exterior of the ion guide at the exit end
Data Source
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AI summary
A mass spectrometer is provided having an ion source for generating ions from a sample in a high pressure region, a first vacuum chamber having an inlet aperture, and an exit aperture. The at least one ion guide can be between the inlet and exit apertures and can include an entrance end and an exit end. The at least one ion guide can have a plurality of electrodes arranged around a central axis defining an ion channel, each of the plurality of electrodes being tapered, a planar surface of each of the plurality of tapered electrodes facing the interior of the at least one ion guide, and the surface gradually being narrowed and tilted inward to provide a smaller inscribed radius at the exit; and a power supply for providing an RF voltage to the at least one ion guide.