The photoacoustic effect at first-order phase transition
The photoacoustic effect at first-order phase transition
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DOI：
10.1063/1.327641
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发表时间：
1980-12
影响因子：
3.2
通讯作者：
P. Korpiun;R. Tilgner
中科院分区：
文献类型：
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作者：
P. Korpiun;R. Tilgner
热性质本质上涉及液体或固体样品对斩波光的吸收的声学响应。最近，第一次实验观察到的光声效应在一阶相变已经出版。在目前的工作中，我们计算的气体中的温度变化在样品的表面，并确定其振幅和相位角。因此，我们解决了微分方程的热传导的介质表现出的温度梯度叠加的温度振荡，由于吸收的光与正弦变化的强度。在介质中存在两个不同热力学相的区域，在转变温度下被界面分开。相变潜热考虑通过边界条件的热流在界面处。我们假设光吸收系数远大于强吸收材料中实现的热扩散系数。应用程序...
Thermal properties are essentially involved in the acoustic response of a liquid or solid sample to the absorption of chopped light. Recently, the first experimental observation of the photoacoustic effect at first‐order phase transitions has been published. In the present work we calculate the temperature variation in the gas at the surface of a sample and determine its amplitude and phase angle. Therefore we solve the differential equation of conduction of heat for a medium exhibiting a temperature gradient superposed by a temperature oscillation due to absorption of light with sinusoidal varying intensity. In the medium there exist two regions of different thermodynamic phases separated by an interface at transition temperature. The latent heat for phase transition is taken into account via a boundary condition for the heat flow at the interface. We have assumed the optical‐absorption coefficient to be much larger than the thermal‐diffusion coefficient realized in strongly absorbing materials. The appl...