Electrostatic Trap Mass Spectrometer Z-Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mass spectrometers, particularly electrostatic traps and time-of-flight mass spectrometers, face limitations in acquisition speed and duty cycle, struggling to match the intensity of modern ion sources exceeding 1E+9 ions/sec while maintaining high resolution and mass accuracy.
Innovation Solution
The electrostatic trap is extended in a Z-direction orthogonal to the plane of isochronous ion motion, allowing for the creation of two-dimensional or torroidal electrostatic fields that enhance space charge capacity and throughput, enabling faster data acquisition and higher resolution through novel field structures and detection methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional electrostatic traps and time-of-flight mass spectrometers are used, then mass resolution and accuracy are maintained, but acquisition speed and duty cycle are limited and cannot match modern ion source intensity
Solution Approach 1:
The patent extends the electrostatic trap from a two-dimensional configuration to a three-dimensional torroidal structure. This dimensional transition increases the space charge capacity and allows higher ion throughput while maintaining the isochronous ion motion required for high mass resolution. The torroidal geometry enables ions to traverse a longer path within a compact volume, achieving both high acquisition speed (50-100 spectra/sec) and high resolving power (100,000).
2Measurement precision
If ion mirror fields are used to achieve high resolution, then mass accuracy is improved, but ion losses occur on grids and space charge throughput is limited
Solution Approach 1:
The patent removes the grid structures from the ion mirror fields, creating grid-free ion mirrors. This extraction of the grid elements eliminates ion losses that occur when ions strike the grid wires, thereby increasing the transmitted ion current and space charge throughput. The grid-free design maintains the electrostatic field configuration necessary for high mass accuracy while allowing significantly higher ion flux to reach the detector.
3Measurement precision
If flight path is extended to diminish initial time spread effects, then resolution is improved, but instrument size increases and acquisition speed decreases
Solution Approach 1:
The patent uses the third dimension (torroidal geometry) to extend the effective flight path length without proportionally increasing the physical instrument footprint. Ions circulate multiple times through the electrostatic fields in a compact toroidal configuration, achieving long effective path lengths for high resolution while maintaining a compact overall instrument size. The isochronous field configuration ensures that this extended path does not compromise acquisition speed.
Solution Approach 2:
The patent implements multi-pass ion trajectories where ions repeatedly traverse the electrostatic field regions multiple times before detection. This continuous circulation allows the ion packets to accumulate phase information over many passes, enhancing resolution without requiring a single extremely long flight path. The isochronous fields ensure that ions of different masses maintain consistent oscillation periods throughout multiple passes, preserving acquisition speed.
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 approach significantly improves the acquisition speed to 50-100 spectra/sec and space charge throughput, making the system compatible with chromatographic separations and tandem mass spectrometry while maintaining high resolution and mass accuracy.
Implementation Method 1
Electrostatic trap (E-Trap) and multi-pass time-of-flight (MP-TOF) mass spectrometers
Implementation Method 2
the analyzer electrostatic fields are designed to provide an isochronous ion motion
Implementation Method 3
provide an isochronous ion motion with respect to small initial energy, angular, and spatial spreads of the ion packets
Implementation Method 4
ion mass-to-charge ratio (m/z) is determined from the ion flight time (T), where T ̃(m/z)0.5
Implementation Method 5
The signal from an image charge detector is analyzed with the Fourier transformation (FT)
Data Source
AI summary
An apparatus 41 and operation method are provided for an electrostatic trap mass spectrometer with measuring frequency of multiple isochronous ionic oscillations. For improving throughput and space charge capacity, the trap is substantially extended in one Z-direction forming a reproduced two-dimensional field. Multiple geometries are provided for trap Z-extension. The throughput of the analysis is improved by multiplexing electrostatic traps. The frequency analysis is accelerated by the shortening of ion packets and either by Wavelet-fit analysis of the image current signal or by using a time-of-flight detector for sampling a small portion of ions per oscillation. Multiple pulsed converters are suggested for optimal ion injection into electrostatic traps.