Electron Multiplier Dynode Voltage Control for Ion Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Time-of-flight mass spectrometers face challenges in extending the life of dynodes due to frequent ionization of high abundance molecules not of interest, which degrades the detector and requires costly and complex electrode arrangements to deflect unwanted ions.
Innovation Solution
An electron multiplier with a power supply circuit that adjusts the voltage between dynodes to selectively prevent or reduce electron flow, allowing for the suppression of unwanted ion detection, thereby extending the life of the detector and simplifying the instrument.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If electrode arrangements are added to deflect unwanted ions, then the detector life is extended, but the device complexity increases
Solution Approach 1:
The patent changes the voltage parameter of the dynodes dynamically. By adjusting the voltage on specific dynodes between detection mode and blanking mode, the system suppresses unwanted ions without adding physical deflection electrodes, thus extending detector life while maintaining simple device structure
Solution Approach 2:
The patent replaces the mechanical/electrical system of physical electrode arrangements for ion deflection with an electrical control system that uses voltage modulation of dynodes to achieve the same ion filtering effect, simplifying the overall device structure
2Duration of action of stationary object
If electrode arrangements are added to deflect unwanted ions, then the detector life is extended, but the manufacturing cost increases
Solution Approach 1:
The invention uses voltage parameter modulation of existing dynodes to achieve ion suppression, eliminating the need for additional electrode components and reducing manufacturing complexity and cost while extending detector life
3Device complexity
If voltage is adjusted to suppress unwanted ions, then the device complexity is reduced, but the energy consumption increases
Solution Approach 1:
The patent uses periodic switching between detection mode and blanking mode, applying high voltage only when needed to suppress specific ion packets. This periodic action reduces average energy consumption compared to continuous high voltage application, while maintaining simple device structure
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 solution effectively reduces the impact of high abundance ions on the detector, extending its lifespan and eliminating the need for complex ion filters, resulting in a more efficient and cost-effective mass spectrometer design.
Implementation Method 1
The ions enter the electron multiplier and strike a dynode. In response, the dynode releases a plurality of electrons in response to each ion that strikes it. Those ions then pass to and strike another dynode. The second dynode then releases multiple electrons in response to each electron that strikes it.
Implementation Method 2
The voltage applied to at least one of the dynodes is adjusted to selectively prevent or satisfactorily reduce the flow of electrons through the electron multiplier.
Data Source
AI summary
A system for detecting ions is disclosed. The system includes a detector having a plurality of dynodes arranged in an electron cascading configuration, and a power supply circuit electrically coupled to the plurality of dynodes. The plurality of dynodes include a first dynode and a second dynode. The power supply circuit is arranged to selectively adjust a potential difference between the first and second dynodes between a detection mode and a blanking mode. A method of detecting ions is also disclosed.