Cylindrical Multi-Reflecting TOF Mass Spectrometer Aberration Control
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Solution Overview
Problem
Multi-reflecting time-of-flight mass spectrometers (MR-TOF) face limitations in sensitivity and resolution due to low duty cycle and aberrations, which restrict their practical application in analytical chemistry.
Innovation Solution
The implementation of a cylindrical topology for the analyzer with specific geometric and electrostatic configurations, including a large curvature radius, small inclination angle, radial deflection, and periodic lenses, to enhance ion beam confinement and reduce aberrations, thereby increasing the drift length and duty cycle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multi-reflecting time-of-flight mass spectrometers are used to increase resolution, then resolution is improved, but duty cycle remains under 1%
Solution Approach 1:
The patent applies cylindrical curvature to the analyzer by wrapping a planar analyzer into a cylinder topology. This curvature extends the drift path length without proportionally increasing the physical footprint, thereby improving resolution while maintaining a compact design that allows for higher duty cycle operation
Solution Approach 2:
The patent transitions from a planar two-dimensional layout to a cylindrical three-dimensional configuration. This dimensional change allows the ion beam to traverse a much longer path length through multiple reflections within a compact volume, simultaneously achieving high resolution and improved duty cycle by optimizing the drift length-to-volume ratio
2Productivity
If cylindrical topology is used to extend drift length, then duty cycle is improved, but curvature effects may introduce aberrations
Solution Approach 1:
The patent carefully controls the curvature radius parameter of the cylindrical analyzer to be sufficiently large, thereby minimizing curvature-induced aberrations. By optimizing this geometric parameter, the system achieves extended drift length for improved duty cycle while maintaining resolution through aberration control
Solution Approach 2:
The patent employs localized electrostatic elements (ring electrodes, periodic lenses) at specific positions within the cylindrical analyzer to correct for local aberrations caused by curvature. These targeted corrections maintain ion beam quality and resolution while allowing the overall cylindrical topology to provide extended drift length
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 resolution and sensitivity of MR-TOF by up to tenfold, allowing for a comprehensive tandem TOF spectrometer within a single analyzer and simplifying differential pumping systems.
Implementation Method 1
cylindrical multi-reflecting electrostatic analyzer
Implementation Method 2
using at least one ring electrode for radial deflection and adjusting such deflection such that ion packets are retarded at the axis of ion minors
Implementation Method 3
by a weak periodic lens with the focal length at least twice exceeding cap-to cap distance
Implementation Method 4
multi-reflecting time-of-flight mass spectrometers
Data Source
AI summary
A method and apparatus are disclosed for improving resolution and duty-cycle of a multi-reflecting TOF mass spectrometer (MR-TOF) by arranging a cylindrical analyzer having an appropriate radial deflection means, means for limiting ion divergence in the tangential direction and a pulsed source providing ion packet divergence of less than 1 mm*deg. There are disclosed embodiments for fifth-order focusing cylindrical ion minors. Separate embodiments provide parallel tandem MS-MS within a single cylindrical MR-TOF.