声致发光气泡内水蒸气的影响

提出了一个单气泡声致发光的简单计算模型.这个模型是在均匀压强近似下，考虑质量和温度在气泡内的非均匀分布，同时考虑了水蒸气在气泡壁上的凝结与蒸发以及水蒸气在气泡内相对惰性气体的质量扩散.通过Saha方程估算气体电离密度，利用电子与离子、电子与中性粒子的轫致辐射，电子与离子的复合辐射公式估算气泡的辐射强度.不考虑化学反应，计算了不同水温时的气泡发光强度，发现当水温在0 ℃时轫致辐射发光模型比较符合实验结果，水温升高时，如水温为20 ℃或以上，轫致辐射发光模型的计算与实验结果出现数量级差别.考虑化学反应，轫致辐射发光模型的计算则总是比实验结果低2个数量级.

Effect of water vapor in sonoluminescing bubble

A simple model of single-bubble sonoluminescence (SBSL) is proposed. The model is based on the approximation of pressure uniformity, while the mass and the temperature in the bubble remain nonuniform. The water vapor evaporation and condensation at the bubble wall and the water vapor diffusion versus the noble gas inside the bubble are also considered. The number density of electrons is estimated by the Saha equation, and in evaluating the light emission from bubbles, bremsstrahlung from electron-neutral particle and electron-ion collisions, as well as recombination radiation, are accounted for. The intensity of light emission at different water temperature is calculated. It has been found that the results obtained using the bremsstrahlung model at a water temperature of 0 ℃ agree with the experimental data. When the wtater tempreture increases, for example at 20 ℃ or above 20 ℃, the calculated results differ from the experimental data in magnitude. If chemical reactions are taken into account, the results by using bremsstrahlung model are always lower than the experimental data by 2 order of magnitude.