Folded TOF Imaging Mass Spectrometer for Aberration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional time-of-flight mass spectrometers with electric sector-based ion paths suffer from low order time and spatial focusing aberrations, leading to poor mass resolution and limited applicability for large field of view imaging due to chromatic and spatial third-order aberrations.
Innovation Solution
A multi-reflecting time-of-flight mass spectrometer with a folded ion path and an ion deflector system that varies voltages to deflect ions across multiple positions on a detector, allowing for high duty cycle, mass, and spatial resolution by mapping ions from a first array of positions to corresponding positions on a second array, while using gridless ion mirrors and sectors to reduce aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electric sector-based TOF mass spectrometer is used, then mass analysis can be performed, but mass resolution is destroyed by large chromatic TOF aberrations when ions have large energy spread
Solution Approach 1:
The ion path is divided into multiple flight path segments using ion mirrors, creating a multi-reflecting time-of-flight mass spectrometer. This segmentation allows the ion beam to traverse the same physical space multiple times, effectively increasing the flight path length and improving mass resolution without requiring a proportionally larger instrument footprint.
Solution Approach 2:
The patent introduces a folded ion path configuration that adds spatial dimensionality to the flight path. By using ion mirrors to reflect ions back and forth through the analysis region, the system converts a linear path into a multi-dimensional trajectory, effectively multiplying the flight path length within a compact volume.
2Measurement precision
If sector-based imaging TOF mass spectrometer is used, then point to point imaging is provided, but spatial third-order aberrations are large making it unsuitable for large field of view analysis
Solution Approach 1:
The imaging function is segmented across multiple flight path reflections. Each reflection off an ion mirror provides an additional opportunity for spatial focusing, and the cumulative effect of multiple reflections compensates for spatial aberrations while maintaining point-to-point imaging capability over a larger field of view.
Solution Approach 2:
The ion beam continuously traverses the analysis region multiple times through the folded path configuration, maintaining continuous interaction with the electric fields for spatial focusing throughout the extended flight path, rather than a single-pass approach.
3Productivity
If conventional TOF mass spectrometer with single flight path is used, then simple structure is maintained, but duty cycle is limited due to sequential analysis requirements
Solution Approach 1:
The folded ion path uses dimensional folding to create a compact configuration where ions traverse the same physical space multiple times. This allows the system to achieve the effect of multiple parallel analysis channels within a single physical structure, effectively increasing duty cycle without proportionally increasing device complexity.
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 enables high-resolution imaging and mass analysis over larger fields of view with reduced spectral overlap and increased duty cycle, overcoming the limitations of sector-based instruments by improving temporal and spatial separation of ions.
Implementation Method 1
The ion deflector may comprise at least one electrode and at least one voltage supply for applying voltages to said at least one electrode, and the voltage supply may be configured to vary the voltage applied to the at least one electrode with time so as to deflect the ions to different positions in said first array of positions at different times
Implementation Method 2
a time-of-flight mass spectrometer with a folded ion path
Implementation Method 3
Such analyzers provide first order time-per-energy focusing and possess imaging properties, i.e. provide point to point transfer with first order tolerance to angular and energy spreads
Data Source
Figure 1~2B
Figure 2C~2D
Figure 3A~3B
AI summary
A time-of-flight mass spectrometer is disclosed comprising: an ion deflector (305) configured to deflect ions to different positions in a first array of positions at different times; a position sensitive ion detector (187); and ion optics (180) arranged and configured to guide ions from the first array of positions to the position sensitive detector (187) so as to map ions from the first array of positions to a second array of positions on the position sensitive detector (187); wherein the ion optics includes at least one ion mirror for reflecting the ions.