Mass Spectrometer Discharge Detection in the Ion Source

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Solution Overview

Problem

In mass spectrometers, frequent measurement abnormalities occur due to both tube clogging and electric discharge in the ion source, making it difficult to identify the cause of the abnormality, leading to decreased maintenance efficiency and sample waste.

Innovation Solution

A mass spectrometer equipped with return current detection units in the ion source and counter electrode power supplies, allowing for the detection of electric discharge currents and identification of the discharge location, thereby facilitating prompt intervention and reducing sample waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If voltage is applied to the ion source for sample ionization, then ionization function is achieved, but electric discharge may occur due to accumulated impurities

Engineering Contradiction:
Improveionization functionVSAvoidelectric discharge
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary detection of electric discharge by monitoring current flow through the ion source before it can cause measurement abnormalities. The detection unit continuously monitors the current, and when discharge is detected, the system takes preliminary action by notifying the operator and preventing abnormal measurements, thus avoiding the harmful effects of electric discharge accumulation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback mechanism where the detection unit continuously monitors the current flow through the ion source, compares it against threshold values, and provides real-time feedback to the control unit. When the current exceeds the threshold indicating electric discharge, the system responds by notifying the operator and preventing further abnormal measurements, creating a closed-loop control system that maintains reliable ionization while preventing harmful discharge effects

Inventive Principle:
Principle #23Feedback

2Productivity

If measurement continues without distinguishing discharge from clogging, then productivity is maintained, but sample waste increases due to inability to identify abnormality cause

Engineering Contradiction:
Improvemeasurement continuityVSAvoidsample waste
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The system provides differentiated feedback by detecting the specific characteristics of electric discharge currents and notifying the operator of the precise abnormality type. This allows the operator to take targeted actions (cleaning the ion source for discharge vs. clearing tubes for clogging), preventing continued measurement with abnormal samples and reducing sample waste while maintaining productivity when the system is properly maintained

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-diagnosis by automatically detecting and identifying the type of abnormality (electric discharge vs. clogging) through current monitoring, eliminating the need for manual troubleshooting. The control unit automatically prevents abnormal measurements and notifies operators of the specific issue, enabling rapid response and reducing both sample waste and downtime

Inventive Principle:
Principle #25Self-service

3Measurement precision

If manual identification of abnormality cause is required, then measurement precision is maintained by avoiding abnormal data, but time is lost in identifying and removing the cause

Engineering Contradiction:
Improvedata qualityVSAvoidmaintenance time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The detection unit performs automatic self-diagnosis by continuously monitoring current flow and identifying electric discharge conditions without human intervention. The control unit automatically compares detected currents against threshold values and determines the presence of electric discharge, eliminating the need for manual identification of abnormality causes and significantly reducing maintenance time while ensuring measurement precision is maintained

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system provides immediate feedback to the operator about the specific type of abnormality detected, enabling rapid response. The control unit continuously monitors and provides real-time information about discharge conditions, allowing the operator to quickly take corrective actions (such as cleaning the ion source) and resume measurements, thereby minimizing both maintenance time and the risk of acquiring abnormal data

Inventive Principle:
Principle #23Feedback

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

The solution enables immediate identification of electric discharge occurrences, reduces sample waste, improves data quality by selecting effective measurement data, and enhances the maintenance efficiency of the mass spectrometer.

Implementation Method 1

an ion source that vaporizes a sample to be analyzed injected from a pretreatment unit and that ionizes the vaporized sample by applying a high electric field to the vaporized sample

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 2

a detection unit that detects a current value flowing through the ion source

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4102540B1A mass spectrometer comprising a control unit for detecting electric discharge and an associated method
Publication Date: 2025.02.12 HITACHI HIGH TECH CORP
  • EP4102540B1 patent drawingFigure 1
  • EP4102540B1 patent drawingFigure 2~3
  • EP4102540B1 patent drawingFigure 4~5

AI summary

In a mass spectrometer, due to impurities accumulated inside a frame, a withstand voltage may decrease, and electric discharge may occur in an ion source, thereby making it impossible to perform normal measurement. Since a result of abnormality measurement due to the electric discharge cannot be distinguished from measurement abnormality caused by clogging of a tube between a pretreatment unit and a needle, there is a problem in that time is required to identify abnormal portions, and a maintenance property is lowered. As a unit for solving the problem, a return current detection unit connected in series between the frame and an ion source power supply that applies a voltage to the needle and a return current detection unit connected in series between the frame and a counter electrode power supply that applies a voltage to a counter electrode are provided. By comparing currents measured by the return current detection units with a predetermined threshold value, occurrence of the electric discharge and a portion where the electric discharge occurs are detected.