Radial Plate Electrode Induction Device for Plasma Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inductively coupled plasma systems, such as ICP-OES, ICP-AAS, and ICP-MS, face challenges due to non-homogeneous current distribution and variable temperature profiles within the plasma, caused by the helical configuration of solenoids, leading to inefficient sample excitation and ion trajectory issues.
Innovation Solution
The use of a device with two plate electrodes configured to provide a loop current along a radial plane, perpendicular to the longitudinal axis of the torch, generates a symmetrical plasma by creating a toroidal magnetic field, which improves temperature uniformity and ion trajectory alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a solenoid with helical configuration is used to generate plasma, then plasma generation is achieved, but the induced current becomes skewed and non-homogeneous over the length of the solenoid
Solution Approach 1:
The solenoid is divided into multiple segments (first solenoid section, second solenoid section, third solenoid section) with different turn densities. Each segment can be independently controlled to optimize current distribution and achieve more uniform plasma temperature along the torch length.
Solution Approach 2:
Different sections of the solenoid are designed with different local characteristics (turn densities). The first section has higher turn density for better coupling, while other sections have adjusted densities to compensate for current skew and achieve homogeneous temperature distribution throughout the plasma.
2Adaptability or versatility
If a single-element solenoid is used, then plasma generation is achieved, but flexibility in controlling the induced current is limited
Solution Approach 1:
The induction device is segmented into multiple independently controllable solenoid sections, each with its own RF power source. This allows flexible control of induced current in different regions, enabling optimization for various operating conditions and sample types.
Solution Approach 2:
The system transitions from a static single-element solenoid to a dynamic multi-section configuration where each section can be independently adjusted in real-time, providing adaptability for different plasma generation requirements and operational modes.
3Productivity
If higher power is used to improve plasma generation efficiency, then sample excitation improves, but carbon buildup increases and torch life decreases
Solution Approach 1:
Different sections of the solenoid are optimized for different functions: the first section with higher turn density provides strong coupling for efficient plasma generation, while other sections are designed to distribute energy more evenly, reducing localized overheating and carbon buildup that would otherwise limit torch life.
Solution Approach 2:
The system optimizes multiple parameters including turn density distribution, RF power allocation to different sections, and operating frequency to achieve efficient plasma generation at lower overall power levels, thereby reducing carbon deposition while maintaining sample excitation effectiveness.
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 results in a more efficient plasma generation with reduced carbon buildup, extended torch life, and the ability to operate at lower powers, enhancing sample transfer and detection sensitivity while minimizing cooling gas requirements.
Implementation Method 1
each of the first and second plate electrodes being configured to provide a loop current along the radial plane of a torch
Implementation Method 2
generates a symmetrical plasma by creating a toroidal magnetic field, which improves temperature uniformity
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A device for sustaining a plasma in a torch is provided. In certain examples, the device comprises a first electrode configured to couple to a power source and constructed and arranged to provide a loop current along a radial plane of the torch. In some examples, the radial plane of the torch is substantially perpendicular to a longitudinal axis of the torch.