Ion Supply System Voltage Control for Mass Spectrometer Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ion transport devices with stacked electrodes in ion supply systems face limitations in transmitting ions due to experimental conditions, such as ion source type, source settings, sample flow rate, sample temperature, and fore vacuum chamber conditions, leading to high ion losses and reduced sensitivity in ion analyzing instruments.
Innovation Solution
An ion supply system with a control system that adjusts the oscillatory voltage applied to the ion transport device's electrodes based on pressure signals from a vacuum gauge, ensuring optimal ion transmission by correlating voltage amplitude with pressure measurements in the vacuum chamber, thereby reducing the influence of experimental and environmental factors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electrostatic optics are employed in vacuum for ion transport and ion focusing, then ion focusing capability is improved, but ion transport losses increase due to large numbers of collisions in atmospheric or low vacuum regions
Solution Approach 1:
The patent introduces a buffer gas (nitrogen or helium) as an intermediary medium in the ion transport path between the atmospheric pressure ion source and the vacuum region. This buffer gas creates a controlled low vacuum region that reduces ion collisions with background gas molecules while maintaining ion transport efficiency. The buffer gas acts as a mediator that protects ions from harmful collisions during transport through the pressure gradient region.
Solution Approach 2:
The patent changes the pressure parameter along the ion transport path by creating a pressure gradient from atmospheric pressure at the ion source to vacuum at the mass analyzer. This is achieved by introducing buffer gas and controlling its flow rate, which optimizes the pressure conditions for ion transport and reduces ion losses during the transition from atmospheric to vacuum conditions.
2Productivity
If ion transport devices with stacked electrodes are used in the fore vacuum chamber, then ion transport efficiency is improved, but sensitivity of the ion analyzing instrument decreases due to high ion losses
Solution Approach 1:
The buffer gas serves as an intermediary that reduces ion collisions with background gas molecules in the fore vacuum chamber, thereby reducing ion losses while maintaining efficient ion transport through the stacked electrode device. The buffer gas creates a more favorable transport environment that preserves ion population.
Solution Approach 2:
The system monitors ion transmission efficiency and adjusts the buffer gas flow rate and electrode voltages in real-time to optimize ion transport. This feedback control ensures that ion losses are minimized while maintaining high transport efficiency through the stacked electrode device.
3Reliability
If fixed oscillatory voltage is applied to the electrodes of the ion transport device, then ion transmission is maintained under specific conditions, but adaptability to changing experimental conditions is reduced
Solution Approach 1:
The patent transforms the static oscillatory voltage application into a dynamic system where voltages are continuously adjusted based on real-time monitoring of ion transmission efficiency and buffer gas flow conditions. This dynamic adjustment allows the ion transport device to adapt to changing experimental conditions while maintaining reliable ion transmission.
Solution Approach 2:
The system incorporates feedback control where ion transmission efficiency is monitored and used to adjust the oscillatory voltage applied to the electrodes. This feedback mechanism enables the system to maintain optimal ion transmission across varying experimental conditions by automatically adapting the voltage parameters.
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 enhances ion transmission efficiency by adapting the oscillatory voltage to pressure changes, ensuring consistent and optimized ion delivery to the mass spectrometer, regardless of experimental conditions or clogging issues, thereby improving the overall sensitivity of the ion analyzing instrument.
Implementation Method 1
In the vacuum chamber, arranged downstream from the ion transport device, is a vacuum gauge. The pressure signal of the vacuum gauge is supplied to the control system supplying the oscillatory voltage to electrodes of the ion transport device.
Implementation Method 2
The control system is supplying the oscillatory voltage to the electrodes of the ion transport device with an amplitude, which is correlated to the pressure signal of the vacuum gauge.
Implementation Method 3
an ion source emitting ions into a fore vacuum chamber
Implementation Method 4
an ion transport device having stacked electrodes arranged in the fore vacuum chamber
Data Source
AI summary
Disclosed herein is an ion supply system, having an ion source emitting ions into a fore vacuum chamber, an ion transport device having stacked electrodes arranged in the fore vacuum chamber, a control system supplying an oscillatory voltage to the electrodes of the ion transport device and a vacuum chamber, arranged downstream from the ion transport device. A vacuum gauge is arranged in the vacuum chamber. The pressure signal of the vacuum gauge is supplied to the control system supplying the oscillatory voltage to electrodes of the ion transport device. The control system adjusts the amplitude of the oscillatory voltage in accordance with the pressure signal.