Lens Free Collision Cell Design for Mass Spectrometers
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Solution Overview
Problem
Existing mass spectrometer collision cells face challenges with gas leakage and insufficient alignment of poles, which affect the accuracy and efficiency of ion collision and pressure management.
Innovation Solution
A collision cell design featuring four elongated semi-circle profile elements attached to a common reference plate, forming a semi-circular channel with semi-circular quad electrodes and insulators to maintain ion alignment and reduce gas leakage, eliminating the need for end seals and pre/post evacuation regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If seals are added at the entrance and exit of the collision cell to reduce gas leakage, then gas leakage is reduced, but device complexity increases
Solution Approach 1:
The patent removes the collision cell from the vacuum chamber entirely, creating a standalone sealed unit. This extraction eliminates the need for seals at the interfaces between the collision cell and vacuum chamber, as the cell is now a self-contained module with its own sealed enclosure. The harmful sealing interfaces are completely removed from the system.
Solution Approach 2:
The collision cell is designed as a separate, modular unit that can be independently sealed and assembled. This segmentation allows the collision cell to be sealed as a discrete component rather than requiring seals at multiple interface points within a larger vacuum chamber, reducing overall device complexity while maintaining gas containment.
2Productivity
If multi-pole structures with ion focusing RF field are used to maintain ion trajectory, then ion collision efficiency is improved, but device complexity increases
Solution Approach 1:
The collision cell design allows ions to naturally follow their trajectories through the collision region without requiring active RF focusing fields. The cell geometry and pressure gradient provide self-focusing effects, eliminating the need for complex multi-pole RF structures while maintaining efficient ion-gas collisions.
Solution Approach 2:
The patent removes the RF focusing fields and multi-pole structures from the collision cell, extracting these complex components entirely. The collision cell operates without these active focusing mechanisms, relying instead on the inherent physics of ion motion in the controlled pressure environment to achieve efficient collisions.
3Reliability
If pre-evacuation and post-evacuation regions are added to manage pressure transitions, then pressure management is improved, but device complexity and volume increase
Solution Approach 1:
The patent removes the need for pre-evacuation and post-evacuation regions by designing the collision cell as a completely sealed unit. Pressure transitions are managed at the interfaces of this sealed module rather than requiring extended evacuation zones, eliminating complex pressure management regions while maintaining reliable pressure control.
Solution Approach 2:
The collision cell is segmented as a distinct sealed module with defined pressure boundaries. This segmentation allows pressure management to be confined to specific sealed interfaces rather than requiring large evacuation regions, reducing both device complexity and overall volume while maintaining effective pressure control.
4Reliability
If seals are added at the entrance and exit of the collision cell to reduce gas leakage, then gas leakage is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent removes the collision cell from the vacuum chamber environment, eliminating the sealing interfaces that would require high precision manufacturing. By extracting the cell as a standalone sealed unit, the design avoids the need for precision seal alignment at multiple critical interfaces, reducing manufacturing precision requirements while maintaining gas leakage prevention.
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 design enhances the alignment of field poles, reduces gas leakage, and improves pressure management, allowing for efficient ion collisions and reduced ion losses, while simplifying fabrication and reducing operational complexity.
Implementation Method 1
The quad electrodes receive electrical potential to form the field required to maintain the ions at the center of the channel, i.e., at the center of the transport axis of the collision cell
Implementation Method 2
Semi-circular insulators are provided on all sides of the channel so as to seal the channel over most of its length from the interior of the mass spectrometer
Data Source
AI summary
An ion collision cell is fabricated by four semi-circular profile elements, all of which are attach to the same reference plate. Consequently, all four elements remain aligned to the same reference plate. The four elements form a semi-circular channel with a semi-circular quad electrodes. The quad electrodes receive electrical potential to form the field required to focus and maintain the ions at the center of the channel. semi-circular insulators are provided on all sides of the channel so as to seal the channel over its length from the interior of the mass spectrometer.