Measurement of electron energy distribution function in liquid plasma with laser Thomson scattering

液体等离子体在环境、生物医学等领域的应用越来越受到人们的关注。本研究采用激光汤姆逊散射法对液体等离子体放电的机理进行了研究。首先，为了研究气体分子在等离子体中的加热机理，利用激光散射测量系统测量了交流功率激励的液体等离子体中环境空气的拉曼散射。从拉曼散射光谱可以得到气体的温度。另一方面，我们尝试用激光汤姆逊散射测量系统测量交流激励乙醇液体等离子体中的电子密度和温度。而乙醇溶液的等离子体发射强度和瑞利散射强度均高于汤姆逊散射强度。因此，认为需要对系统进行改进，以实现较高S/N比的测量。

Liquid plasma has been attracted in many kinds of application areas such as environmental and bio-medical fields. In this study, laser Thomson scattering method was applied to clarify a mechanism of the liquid plasma discharge. Firstly, in order to investigate heating mechanism of gas molecular in the plasma, Raman scattering due to ambient air in an AC power excited liquid plasma was measured by the laser scattering measurement system. From the Raman scattering spectra, the gas temperature was obtained. The gas temperature at the time of discharge was estimated around 690 K, On the other hand, we tried to measure the electron density and temperature in an AC excited ethanol liquid plasma with a laser Thomson scattering measurement system. However, the intensities of plasma emission and Rayleigh scattering by drop of ethanol were higher than that of Thomson scattering. Therefore, it is considered that the system need to be improved to realize the measurement with higher S/N ratio.