Working Parameters Optimization And Device Improvement Of A Small-size Glow Discharge System

Glow Discharge Spectrometer can analyze and inspect metal block samples and various coating samples,and can be widely used in surface composition analysis,product quality inspection and new material research and development.In recent years,research on glow discharge spectrometer related technology has become a research hot spot in the field of analytical instruments at country and abroad.The miniaturization design of the glow discharge system can make up for the deficiencies of the traditional large-scale spectral system,such as its complicated structure and high price.It can be applied to small analytical laboratories,various research laboratories,material quality inspection departments,etc.In this paper,based on the miniaturized glow discharge experimental platform,the sample loading device is improved,and the optimal operating parameters for the analysis of copper-based and iron-based bulk samples using this system are studied.This paper designs a pneumatic sample loading device for a small-scale glow spectrum analysis system,replacing the original manual sample loading device of the experimental platform.The experimental verification shows that the application of pneumatic devices improves the sample’s sputtering pit type and improves the sputtering stability.Pneumatic sample loading can effectively control the gap between the sample and the cathode disk to be fixed at about 0.2 mm,so as to achieve better limiting discharge effect.In this paper,a small RF glow discharge spectroscopic detection system was used to sputter-excite the metallic bulk samples(iron-based samples and copper-based samples),and then the spectral intensity of each element under various operating parameters was measured by the Avantes CCD spectrometer.Using the controlled variable method,a large number of experiments were performed on metal samples under different operating parameters.Spectral intensity spectra of various elements in the sample and glow photograms during sputtering were obtained.The trend curves of the spectral intensity of each element as a function of the pressure of argon are obtained and the trend curves of the spectral intensity of each element as a function of the RF power are obtained.The analysis can be obtained,the effective range ofargon gas pressure in this system is 150Pa≦n≦350Pa,and the effective range of RF power is15W≦n≦60W.When the argon gas pressure in the glow discharge chamber is 270 Pa and the RF power is 50 W,the matrix elements(Cu,Fe)in the metal sample have the strongest spectral signal intensity.In this paper,the system precision experiment under the optimal operating parameters is performed and the measured data are given.The experimental determination,the system can detect copper-based samples containing Zn,Fe,P and N and other elements.This article compares the analytical precision of the instrument before and after the improvement of the sample loading device.When analyzing copper-based samples,RSD values increased from12.6% to 3.2%;when analyzing iron-based samples,RSD values increased from 12.1% to9.5%.