An undergraduate laboratory experiment to determine the critical point of SF 6 using light scattering at selected wavelengths
An undergraduate laboratory experiment to determine the critical point of SF 6 using light scattering at selected wavelengths
复制标题
使用选定波长的光散射确定 SF 6 临界点的本科生实验室实验
DOI：
10.1088/1361-6404/aba225
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发表时间：
2020
影响因子：
0.7
通讯作者：
Murray A
中科院分区：
文献类型：
--
作者：
Murray A
分子和原子在室温和压力下通常是气态的，随着温度的降低或压力的增加，它们会液化或凝固。在这里详述的装置中，商业电池含有加压的SF6，因此它既以气态又以液态存在，在室温下两者的密度相似。然后，通过提高电池的温度，使液体和气体的密度相等，就可以研究相图上的临界点。在这种情况下，通过电池的光被流体中的密度波动高度散射。通过测量透射光作为温度和波长的函数，可以得到临界指数，并研究了波长对光散射的影响。
Molecules and atoms that are normally gaseous at room temperature and pressure will liquefy or solidify as their temperature reduces or their pressure increases. In the apparatus detailed here a commercial cell contains pressurized SF 6 so that it exists in both gaseous and liquid states, with the density of both being similar at room temperature. The critical point on the phase diagram can then be investigated, by elevating the temperature of the cell so the densities of liquid and gas equalize. Under these conditions light passing through the cell is highly scattered by density fluctuations in the fluid. By measuring the transmitted light as a function of both temperature and wavelength, the critical exponent can be derived and the effects of light scattering with wavelength investigated.