Spectral light types

With t = 0 the present expression reduces to the result obtained in Eq. (3.28). If, e.g., t = 2, then spectral exchange takes place both within the branches of an isotropic scattering spectrum (Fig. 6.1) and between them. The latter type of exchange is conditioned by collisional reorientation of the rotational plane, whose position is determined by angle a. As a result, the intensity of adsorbed or scattered light is redistributed between branches. In other words, exchange between the branches causes amplitude modulation of the individual spectral component, which accompanies the frequency modulation due to change of rotational velocity. 

Procedure Set up an acoustic reactor in a light-proof cabinet with a photomultiplier (PM) tube positioned facing the cell as shown in Fig. 15.3a and b. Fill the cell with distilled water and close the cabinet. A potential should now be applied to the PM tube, the output (spectrally integrated) of which is produced on an oscilloscope (note that the ultrasound cell can easily be placed inside a commercial spectrometer in order to record the emission spectrum). Switch on the ultrasound and you should observe on the oscilloscope a change in voltage, directly proportional to the intensity of sonoluminescence emission. The following experiments can be performed to explore the different types of light emission and some of the factors that influence these emission processes. 

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