Orthogonal TOF Mass Spectrometer Ring Electrode Offset for Higher Resolution
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Solution Overview
Problem
Conventional orthogonal acceleration time-of-flight mass spectrometers face challenges in achieving high mass-resolving power without compromising signal intensity and production cost, particularly due to variations in ion energy distribution and turnaround time, which are not adequately addressed by existing configurations.
Innovation Solution
The configuration includes an ion ejector, orthogonal accelerator, a ring electrode with a shifted central axis, a reflectron electrode, and an ion detector, which reduces angular spread and turnaround time, improving mass-resolving power without requiring high-output power sources or increasing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a steeper potential gradient is created within the acceleration space to shorten turnaround time, then mass-resolving power is improved, but the spread of imparted energy depending on incident position becomes greater and may exceed the reflectron's compensation range
Solution Approach 1:
The invention shifts the problem from one-dimensional energy compensation to two-dimensional control by introducing axial position adjustment. By moving the extraction region axially relative to the acceleration space, the system can selectively extract ions with specific energy characteristics, effectively filtering the energy spread without requiring steeper potential gradients that would exceed reflectron compensation capabilities.
2Loss of time
If the central axis of the ring electrode is shifted from the central axis of the ion ejector, then angular spread of ions is reduced and turnaround time is shortened, but the configuration complexity increases
Solution Approach 1:
The invention deliberately introduces asymmetry by shifting the ring electrode's central axis relative to the ion ejector's central axis. This asymmetric configuration is designed to reduce the angular spread of ions entering the acceleration space, thereby shortening turnaround time. The asymmetry is carefully controlled to achieve the desired ion beam quality without excessive complexity.
3Device complexity
If conventional alignment is used with central axes coincident, then device complexity is minimized, but angular spread of ion beam increases and mass-resolving power decreases
Solution Approach 1:
The invention moves from conventional one-dimensional axial alignment to a two-dimensional alignment strategy by introducing radial offset between the ring electrode and ion ejector axes. This additional degree of freedom allows optimization of ion beam quality (reducing angular spread) without requiring complex multi-electrode configurations, thus improving mass-resolving power while maintaining reasonable 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
This configuration enhances mass-resolving power by reducing angular spread and turnaround time, maintaining signal intensity and mass accuracy, and avoiding the need for high-output power sources and increased production costs.
Implementation Method 1
A potential gradient directed from the pusher electrode to the puller electrode is created to impart kinetic energy to the ions within the acceleration space
Implementation Method 2
accelerate ions in a direction orthogonal to the direction in which the ions are ejected
Implementation Method 3
a reflectron electrode configured to create a repelling electric field for reversing the direction of the ions accelerated by the orthogonal accelerator
Implementation Method 4
a ring electrode located between the ion ejector and the orthogonal accelerator, the ring electrode having an opening for allowing ions to pass through
Data Source
AI summary
An orthogonal acceleration time-of-flight mass spectrometer (1) includes: an ion ejector (123) which ejects measurement-target ions in a predetermined direction; an orthogonal accelerator (132) which accelerates ions in a direction orthogonal to the direction in which the ions are ejected; a ring electrode (131) located between the ion ejector and the orthogonal accelerator, the ring electrode having an opening for allowing ions to pass through and arranged so that the central axis (C2) of the opening is shifted from the central axis (C1) of the ion ejector in a direction along the axis of the acceleration of the ions by the orthogonal accelerator; a reflectron electrode (134) which creates a repelling electric field for reversing the direction of the ions accelerated by the orthogonal accelerator; and an ion detector (135) which detects ions after the direction of flight of the ions is reversed by the reflectron electrode.