Mass Spectrometer Contra-Flow Gas Injection for Neutral Contamination

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Solution Overview

Problem

Conventional mass spectrometers face contamination issues due to the transmission of undesired ions and neutral molecules from atmospheric pressure ion sources, leading to decreased sensitivity and increased maintenance costs, particularly in downstream high-vacuum chambers.

Innovation Solution

A contra-flow configuration of neutral gas is introduced to divert neutral molecules and contaminants away from the high-vacuum stages by flowing counter-currently or at an angle to the ion stream, using a curtain gas system and internal curtain gas injection to prevent fouling of sensitive components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the inlet orifice size is increased to allow more ions of interest to enter the ion guide, then ion transmission and sensitivity are improved, but more neutral molecules and contaminants are also transmitted into the high-vacuum chamber, worsening contamination of downstream components

Engineering Contradiction:

ImprovesensitivityVSAvoidcontamination

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes neutral molecules and contaminants from the ion beam path using a curved Q0 ion guide that physically separates the trajectories of ions and neutrals, allowing ions to be focused onto the analyzer while neutrals are diverted to strike the chamber wall

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a straight ion guide path, the patent inverts the approach by introducing a curved path that exploits the different behaviors of ions and neutrals in the electric field, causing neutrals to follow a different trajectory than ions

Inventive Principle:

Principle #13The other way round (Inversion)

2Productivity

If continuous ion generation is maintained during non-data collection periods, then ion source efficiency is preserved, but contamination of the mass analyzer accelerates, worsening maintenance requirements

Engineering Contradiction:

Improveion generation efficiencyVSAvoidmaintenance downtime

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent converts the harmful effect of continuous ion generation (which causes contamination) into a beneficial separation process where the curved ion guide uses the presence of ions to create electric field conditions that actively divert neutrals away from sensitive components, making the continuous operation compatible with reduced contamination

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Measurement precision

If downstream mass analyzer components are cleaned more frequently, then sensitivity is maintained, but system downtime and operational costs increase

Engineering Contradiction:

ImprovesensitivityVSAvoidthroughput

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent performs preliminary action by implementing the curved Q0 ion guide that prevents neutral contamination before it can reach and foul the mass analyzer components, eliminating the need for frequent cleaning interruptions

Inventive Principle:

Principle #10Preliminary action

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 reduces contamination, increases throughput, and decreases downtime for cleaning and maintenance by effectively blocking neutral molecules and reducing ion transmission during non-analytical periods, thereby maintaining sensitivity and robustness of the mass spectrometer.

Implementation Method 1

The contra-flow disrupts the axial gas flow and diverts neutral molecules and other undesirable contaminants before they reach the high vacuum stages

Methodology Applied

Scientific EffectMomentum transfer: Conservation of Momentum

Implementation Method 2

a radio frequency (RF) signal applied to the ion guide provides collisional cooling and radial focusing along the central axis of the ion guide

Methodology Applied

Scientific EffectCollisional cooling:

Data Source

PatentUS12002672B2Apparatus and methods for reduced neutral contamination in a mass spectrometer

Publication Date: 2024.06.04 DH TECH DEVMENT PTE

AI summary

Apparatus and methods for controlling contamination of components contained within the high-vacuum chambers of mass spectrometer systems are provided. The apparatus and methods employ a beam of neutral gas injected in a contra-flow configuration to incoming particle stream from the ionization chamber. The contra-flow can be in the directly opposite counter-flow direction (e.g., 180 degrees) or at a cross-flow angle to the incoming ion stream (e.g., flowing at an angle between about 10 degrees and 170 degrees). The contra-flow disrupts the axial gas flow and diverts neutral molecules and other undesirable contaminants before they reach the high vacuum stages (e.g., beyond the IQ0 orifice) of the spectrometer. By reducing the transmission of contaminants into the sensitive components housed deep within the mass spectrometer, the present invention can increase throughput, improve robustness, and/or decrease the downtime typically required to vent/disassemble/clean the fouled components.