Helium Plasma Tuning for Stable VUV Emission
Solution Overview
Problem
Discharge ionization current detectors, particularly low-frequency dielectric barrier discharge ionization detectors, face fluctuations in detection results due to impurities in helium gas, leading to reduced precision and reproducibility of measurements.
Innovation Solution
A tuning method is developed to optimize the emission spectrum of helium plasma by adjusting the purity, flow rate of helium gas, and voltage parameters to maximize the intensity of the emission line at 640 nm, which is indicative of stable helium molecular ion generation, thereby stabilizing the vacuum ultraviolet light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-purity helium gas is used to maintain stable electric discharge, then measurement precision and reproducibility improve, but the complexity of gas purification and flow control increases
Solution Approach 1:
The patent implements a feedback control system that continuously monitors the emission intensity at 640 nm and automatically adjusts the helium gas flow rate to maintain optimal plasma conditions. This closed-loop control eliminates the need for complex manual purification systems while ensuring stable electric discharge and high measurement precision.
Solution Approach 2:
The system uses the plasma emission spectrum itself as a diagnostic tool to monitor gas purity and adjust flow rates automatically. The emission line at 640 nm serves as an intrinsic indicator of plasma stability, allowing the system to self-regulate without external intervention or complex purification equipment.
2Stability of the object's composition
If the emission intensity at 640 nm is maximized to indicate stable helium molecular ion generation, then vacuum ultraviolet light stability improves, but the need for spectral monitoring and adjustment increases device complexity
Solution Approach 1:
The patent monitors the emission intensity at the specific wavelength of 640 nm as a key parameter to assess plasma stability. By focusing on this single diagnostic parameter rather than full spectral analysis, the system achieves stable vacuum ultraviolet light emission with minimal monitoring complexity. The flow rate is adjusted based on this parameter to optimize molecular ion generation.
3Reliability
If impurities in helium gas are minimized to stabilize electric discharge, then detection precision improves, but the cost and complexity of gas handling systems increase
Solution Approach 1:
The patent replaces complex mechanical gas purification systems with a simpler flow-controlled system that uses the plasma emission spectrum as a real-time indicator of gas quality. By monitoring the 640 nm emission line, the system can detect impurity effects and adjust flow rates accordingly, eliminating the need for elaborate purification equipment while maintaining reliable electric discharge.
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 generates stable and strong vacuum ultraviolet light, enhancing the precision and reproducibility of measurements in discharge ionization current detectors by minimizing impurity effects and optimizing plasma conditions.
Implementation Method 1
an alternating-current low-frequency voltage is applied to a discharge electrode formed on the outside of the dielectric substance, thereby plasma is generated in the space
Implementation Method 2
plasma is generated in the space
Implementation Method 3
electric discharge is utilized
Implementation Method 4
a sample is ionized by utilizing the emission of light (vacuum ultraviolet light and the like) of the plasma
Implementation Method 5
a sample is ionized by utilizing the emission of light (vacuum ultraviolet light and the like) of the plasma
Data Source
AI summary
An adjusting method for a discharge ionization current detector of the present invention is provided for a discharge ionization current detector for a gas chromatograph, which improves the precision and reproducibility of measurements results of the detector. The discharge ionization current detector adjusts at least one of purity of introduced helium gas, a flow rate of the introduced helium gas, an amplitude of voltage of the low-frequency dielectric barrier discharge, and a frequency of the voltage of the low-frequency dielectric barrier discharge so that intensity of light having a wavelength of 640 nm reaches the maximum in a range of wavelengths of 250 to 700 nm with respect to light emitted by the helium plasma.