Off-Axis Deflector Lens for Mass Spectrometry Baseline Offset Reduction

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Solution Overview

Problem

Current mass spectrometry systems face challenges in reducing signal errors due to unwanted photons and neutral species, particularly when operating in vacuum environments, leading to baseline signal offsets that obscure true spectra, and require large geometries and high voltages, which can be unsafe and inefficient.

Innovation Solution

The implementation of a cylindrical ion flow-direction structure with off-axis apertures between the ion source and analyzer, utilizing a cylindrically symmetric electric field to prevent unwanted particles from reaching the detector, allowing for lower voltage operation and reduced baseline signal offsets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a sightline is provided between ion source and detector, then ion transmission is improved, but baseline signal offsets increase due to unwanted photons and neutral species

Engineering Contradiction:

Improveion transmissionVSAvoidbaseline signal offset

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The detector is positioned off-axis relative to the ion source, breaking the symmetric alignment that would allow direct sightlines. This asymmetric configuration blocks unwanted photons and neutral species from reaching the detector while maintaining ion transmission through the mass analyzer, thereby reducing baseline signal offsets without significantly compromising ion transmission efficiency

Inventive Principle:

Principle #4Asymmetry

2Object-affected harmful factors

If additional field-generating elements are added to divert ion beams off-axis, then sightline prevention is improved, but device complexity increases

Engineering Contradiction:

Improvesightline preventionVSAvoidfield-generating elements

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The harmful sightline path is eliminated by removing the direct alignment between source and detector, rather than adding complex field-generating elements to divert the beam. The off-axis detector positioning inherently prevents the sightline without requiring additional deflectors or field-generating structures, thus reducing device complexity while maintaining effective sightline prevention

Inventive Principle:

Principle #2Taking out (Extraction)

3Ease of operation

If high voltages are used for beam diversion, then ion beam control is improved, but operational safety deteriorates

Engineering Contradiction:

Improveion beam controlVSAvoidoperational safety

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

Instead of using high voltages to actively divert the ion beam away from the detector, the solution inverts the approach by positioning the detector off-axis so that the beam naturally does not reach it. This passive geometric configuration eliminates the need for high-voltage beam diversion systems, maintaining ion beam control through the mass analyzer while significantly improving operational safety by eliminating high-voltage components

Inventive Principle:

Principle #13The other way round (Inversion)

4Productivity

If large quadrupole geometries are used, then ion transmission is improved, but device size increases

Engineering Contradiction:

Improveion transmissionVSAvoidquadrupole geometry size

Core Design Contradiction:

ProductivityVSVolume of moving object

Solution Approach 1:

The solution moves the detector positioning from the traditional axial dimension to an off-axis position in a different spatial dimension. This dimensional change allows for more compact quadrupole geometries while maintaining effective ion transmission, as the off-axis positioning naturally prevents direct sightlines without requiring larger aperture sizes or extended component dimensions

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 effectively reduces baseline signal offsets, minimizes noise, and improves safety by operating at lower voltages, resulting in a more robust and accurate mass spectrum without the need for additional field-generating elements.

Implementation Method 1

utilizing a cylindrically symmetric electric field to prevent unwanted particles from reaching the detector

Methodology Applied

Scientific EffectElectric field: Electric Field

Data Source

PatentUS8796620B2Mass spectrometry for gas analysis with a one-stage charged particle deflector lens between a charged particle source and a charged particle analyzer both offset from a central axis of the deflector lens

Publication Date: 2014.08.05 MKS INSTR INC

AI summary

Apparatus, methods and systems are provided to inhibit a sightline from a charged particle source to an analyzer and for changing a baseline offset of an output spectrum of an analyzer. A supply of charged particles is directed through a hollow body of a deflector lens that is positioned relative to a charged particle source and an analyzer. A flow path along a preferred flow path through a deflector lens permits passage of the ions from the source to the detector while inhibiting a sightline from the detector to the source in a direction parallel to the central longitudinal axis of the deflector lens.