中文摘要：

利用可调谐二极管激光吸收光谱技术对低气压氩气介质阻挡放电等离子体进行诊断,重点考察了Ar亚稳态1s5和1s3的数密度和气体温度随放电电压,气压,流量,极板间距,以及随N2配比的变化情况。实验基于朗伯-比尔（Lambert-Beer）定律,通过计算吸收谱线的吸收峰面积求取Ar亚稳态的数密度,同时对谱线进行Voigt拟合得到多普勒展宽,进而求出气体温度。Ar亚稳态主要由电子碰撞产生,但同时电子也会碰撞亚稳态发生猝灭作用,从而使数密度减少;气体温度则与等离子体的实际功率、电子的状态以及粒子之间的碰撞有关。实验结果表明在本实验条件范围内,Ar亚稳态数密度和气体温度随放电电压和流量的增大都先增大,之后逐渐趋于平缓,但两者随流量的变化幅度都较之随放电电压的小,增长较缓慢。随气压的升高,Ar亚稳态数密度和气体温度先增加并达到一个极大值,而之后逐渐降低。实验数据表明,气压对谱线展宽有较明显的影响作用。适当增大极板间距,Ar亚稳态数密度明显降低,但气体温度却有所升高。N2的加入对亚稳态有很强的猝灭作用,0.5%的N2就会使数密度下降50%,但随着N2浓度的进一步增大,其数密度不再明显降低。

英文摘要：

Gas temperature and density of Ar metastable state in DBD Ar（Ar/N2）plasma were measured using the tunable diode-laser absorption spectroscopy technology at low pressure.The variation trend of the densities of Ar metastable state 1s5,1s3 and gas temperature with voltage,pressure,gas flow,electrode distance and N2 concentration was studied.The density of Ar metastable was obtained by calculating the absorption peak area of absorption line based on the Lambert-Beer law,while gas temperature was determined with Doppler width of the absorption line in Voigt fitting.We deduced that the main source of the Ar metastable was the electron-impact excitation from the ground state,and the main loss process was the electron quenching.In addition,the actual discharge power,the electron state and the collision between particles were responsible for the variation of gas temperature.It was found that,when the voltage and gas flow increasing,both temperature and densities of 1s5,1s3 shown the similar trends,which increasing rapidly at first and then slowly.In addition,the variation with gas flow was smaller than that with gas flow.With pressure increasing,temperature and densities of 1s5,1s3 increased till to a max value and then decreased.Meanwhile,the experimental data indicated that the pressure had a greater effect on spectral line width.To increase theelectrode distance properly,the density of 1s5,1s3 decreased while the gas temperature increased.N2 added to Ar presented a great negative effect on the density of Ar metastable state.Even 0.5% N2 added to Ar,the densities of 1s5 and 1s3decreasedrapidly about to 50%,but then more N2 added,there was no obvious decrease about density.