金属氢化物作阴极的真空弧离子源,假设其放电产生双温度的非平衡态Ti-H等离子体,其内部的气体解离过程和粒子电离过程分别由Culdberg-Waage解离方程和Saha电离方程进行描述,结合原子发射光谱以及电荷准中性条件,求出Ti-H等离子体的电子温度Te、重粒子温度Th和粒子数密度之后,可更进一步对等离子体的质量密度、焓、比热容等热力学参数进行描述。在不同的电子数密度下,研究各参数随变量θ(电子温度Te与重粒子温度Th的比值)变化的情况。计算结果显示: 电子数密度已知,随θ值升高,除氢气分子数密度外,等离子体温度和单原子粒子数密度的计算结果均变化甚微。高电子数密度时,等离子体中单原子粒子占绝对优势,热力学参数由其控制; 低电子数密度下,随θ值的升高,等离子体逐步由单原子粒子占优势转为氢气分子占绝对优势,热力学参数的变化情况表现出相同的规律。

Assuming that the Ti-H plasma generated by vacuum arc ion source using Ti-H solid solution was a non-equilibrium two-temperature plasma. The dissociation of hydrogen and the ionization of atomic particles were described by Culdberg-Waage dissociation equation and Saha ionization equation, respectively. Combining plasma atomic emission spectra and plasma’s charge quasi-neutral condition, the electron temperature, heavy particle temperature and particle number density were calculated. Then the thermodynamic parameters including mass density, enthalpy and specific heat were described. Under different electron densities, the changes of each parameter with the ratio of the electron temperature to heavy particle temperature named θ were studied. The calculated results showed: under the same electron number density, with the growth of θ, in addition of the hydrogen molecule’s number density, the electron temperature and the number densities of all single-atomic particles were all almost not changed. When the electron density was high, single-atomic particles were dominant in the plasma and the thermodynamic parameters were controlled by them. On the other hand, with low electron density, with the growth of θ, hydrogen molecules in the plasma became dominant gradually, and the variation of the thermodynamic parameters exhibited the same trend.