Excitation Performance Investigation Of Micro-ICP Excitation Source

Miniaturization and integration is one development trend for optical spectrum instruments.The miniaturization of its excitation source play an important role in this development. Currently, inductively coupled plasma(ICP) excitation source is most widely used in atomic emission spectrometry instruments, so the research on micro-ICP excitation source have a major impact on the miniaturization of optical spectrum instruments. In this thesis, research and improvement of excitation performance for the excitation source is the main task. Its working gas has been chosen and background spectral lines has been detected. Ideal working parameters and excitation temperature were also researched. Micro-ICP excitation source excited some sample gas such as methane and butane, detection and qualitative analysis of the spectral lines were done.This paper summarized the development trend of spectroscopic instruments and recent research on micro-ICP excitation sources. Made a brief introduction on the production theory of atomic emission spectroscopy, principles of chemical element qualitative analysis and quantitative analysis and analysis methods. Micro-ICP excitation source excited argon, air, argon and air mixture,spectral lines of excitation light were detected by AvaSpec-3648-USB2 miniature fiber optic spectrograph which made by Avantes company from Netherlands. 27 argon atomic spectral lines and 22 nitrogen molecular atomic spectral lines were detected which are background spectral lines. Argon is better working gas after experiment contrast with air. According to argon line intensity, experiment research on the working parameters selection and argon excitation temperature have been done. When the micro-ICP excitation source ideally working, the parameters of plane spiral coil, its number of turns is 3, external diameter is 10 mm. Argon line intensity increased when RF power increased, increased firstly and then decreased when Ar pressure increased. Ideal RF power is from 18 to 22 W, ideal working gas pressure is from 50 to 70 Pa. Argon excitation temperature increased when RF power and Ar pressure increased, the calculated argon excitation temperature is between 1600 and 3000 K.Micro-ICP excitation source excited sample gases such as methane and butane, and their spectral lines were detected and analysed. 22 methane emission spectral lines and 13 butane emission spectral lines were detected. In the meantime, some other sample gas like ethylalcohol and acetylene were also did the same experiment, but the spectral lines were not detected.The research results show that the micro-ICP excitation source can be applied in qualitative analysis of methane and butane. With further research carring on, the micro-ICP excitation source can be used in spectrograph as one kind of new excitation source for gas sample is hopeful.