Curved Ion Source Electrodes for Compact Mass Spectrometer Convergence

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Solution Overview

Problem

Conventional ion sources for time-of-flight mass spectrometers cannot simultaneously achieve temporal and spatial convergence, leading to suboptimal peak intensity and peak width, which is exacerbated by the need for larger instrument sizes that hinder portability.

Innovation Solution

An ion source with a push-out electrode in a cup-like shape, a pull-out electrode with a mesh-like form and holes, and a pull-in electrode with a pinhole, where the push-out and pull-out electrodes have a curved depression opposite to the ion travel direction, creating an optimal potential distribution for ion acceleration and convergence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If large parallel plate electrodes are used as push-out and pull-out electrodes to achieve both temporal convergence and spatial convergence, then ion convergence performance is improved, but instrument size increases

Engineering Contradiction:
Improveion convergence performanceVSAvoidinstrument size
Core Design Contradiction:
Manufacturing precisionVSVolume of stationary object

Solution Approach 1:

The patent applies curvature to the push-out and pull-out electrodes by forming depressions on their inner surfaces. This curved geometry creates a non-uniform electric field distribution that focuses ions both spatially and temporally, achieving convergence performance comparable to large parallel plate electrodes while using a compact structure. The curved surfaces redirect ion trajectories to converge at the desired focal point without requiring large electrode areas.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent implements local quality by creating depression regions specifically on the inner surfaces of the push-out and pull-out electrodes where ions are generated and accelerated. This localized geometric modification concentrates the electric field in specific areas to achieve optimal ion convergence, rather than requiring the entire electrode surface to be large and planar. The depression depth and curvature radius are optimized to provide the necessary field distribution for convergence.

Inventive Principle:
Principle #3Local quality

2Volume of stationary object

If the ion source size is reduced to improve portability, then instrument portability is improved, but the ability to perform both temporal convergence and spatial convergence deteriorates

Engineering Contradiction:
Improveinstrument sizeVSAvoidion convergence performance
Core Design Contradiction:
Volume of stationary objectVSManufacturing precision

Solution Approach 1:

The curved depression surfaces in the compact ion source create a focused electric field pattern that compensates for the reduced overall size. The curvature radius of the depression is specifically designed to match the required focal length for ion convergence, allowing the compact structure to achieve the same convergence performance as larger conventional designs. This enables portable mass spectrometers to maintain high ion convergence capabilities.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent optimizes specific geometric parameters of the curved electrodes, including depression depth, curvature radius, and electrode spacing, to achieve optimal ion convergence in a compact configuration. By carefully adjusting these parameters, the ion source maintains effective temporal and spatial convergence despite the reduced overall size, enabling portable applications without sacrificing analytical performance.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If conventional ion source designs are used to maintain temporal and spatial convergence, then ion convergence is maintained, but detection sensitivity and mass resolution are compromised due to suboptimal peak intensity and peak width

Engineering Contradiction:
Improveion convergenceVSAvoidmass resolution and detection sensitivity
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The curved depression surfaces create an optimized electric field distribution that simultaneously improves temporal convergence (peak width) and spatial convergence (peak intensity). The curvature is designed to equalize the flight times of ions from different positions in the source (temporal convergence) while focusing them to a tight spatial point (spatial convergence). This dual optimization produces sharper mass spectral peaks with both high intensity and narrow width, improving both detection sensitivity and mass resolution.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent designs the curved electrode surfaces to create equipotential lines that are properly oriented relative to the ion extraction direction. This equipotential configuration ensures that ions experience uniform acceleration regardless of their initial positions, improving temporal convergence. Combined with the curved geometry, this achieves optimal peak shape characteristics that enhance both detection sensitivity and mass resolution.

Inventive Principle:
Principle #12Equipotentiality

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 allows for efficient temporal and spatial convergence of ions, increasing the output ion amount and maintaining high performance while reducing instrument size, thus enabling smaller, high-performance mass spectrometers for portable analysis.

Implementation Method 1

an electron gun (7) that emits an electron beam, and a push-out electrode (1), a pull-out electrode (2) and a pull-in electrode (3), wherein the electron beam emitted from the electron gun (7) is introduced into an ion generation area (4) between the push out electrode (1) and the pull out electrode (2) in which ions are to be generated

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 2

a means configured to initially apply in the ion source voltages of the same potential to the push-out electrode and the pull-out electrode, this potential being different from the potential of the pull-in electrode and after that a potential difference between each two of the push-out electrode, the pull-out electrode, and the pull-in electrode, so that the ions generated in the ion generation area are pulled toward an acceleration area between the pull out electrode and the pull in electrode by the electrical field formed by the push-out electrode and the pull-out electrode and are accelerated in the acceleration area

Methodology Applied
Scientific EffectElectrical field: Electric Field

Data Source

PatentEP2413346B1Ion source, and mass spectroscope provided with same
Publication Date: 2022.05.04 MSI TOKYO
  • EP2413346B1 patent drawingFigure 1~2
  • EP2413346B1 patent drawingFigure 3(a)~3(b)
  • EP2413346B1 patent drawingFigure 4(a)~4(b)

AI summary

An ion source (10) is provided with a push-out electrode (1), a pull-out electrode (2), and a pull-in electrode (3) all for ionizing a sample and accelerating generated ions in a pulsed manner, wherein the push-out electrode (1) and/or the pull-in electrode (3) has a curved surface shape having a depression curved in the direction opposite to the direction of travel of the ions. As a result, a compact ion source capable of temporally and spatially focusing ions and outputting the ions, and a compact time-of-flight mass spectroscope with good detection resolution and detection sensitivity which is provided with the compact ion source can be provided.