Studies On The Effect Of Different Noble Gases On Sonoluminescence

The purpose of this thesis is to study the effect of different noble gases on the sonoluminescence and to analyze the sonoluminescence in different noble gases.Using the numerical simulation of nonlinear ordinary differential equations,the sonoluminescence properties of different noble gas bubbles in phosphoric acid solution were studied respectively,and the influence of different noble gases on the sonoluminescence was analyzed.At the same time,the spectra of the MBSL with different noble gases in phosphoric acid solution were also measured.Firstly,the influence of the noble gas bubbles on single bubble sonoluminescence is analyzed by considering the effect of the van der waals equation in the gas's the effective polytropic exponent and thermal diffusion coefficient.Using R-P equation,the relative radius and maximum temperature of He,Ar and Xe bubbles on single bubble sonoluminescence were calculated.The light intensity of the corresponding noble gases is calculated by the bremsstrahlung model.It is clarified that the maximum temperature and maximum light intensity in the bubble increase with the molecular weight of the noble gas increase.Secondly,When the distances between bubbles are small enough,the pressure of acting on the bubble doesn't as same as the external driving pressure,because of the radiation pressure wave of the neighboring bubbles.The changes of the radius,the secondary Bjerknes force and the temperature of the double bubble,which is having different size,distance,and noble gas,during the process of ultrasonic cavitation are calculated with using the improved K-M equations considering the bubble-radiated pressure waves.From the calculated results,the following conclusions are made:when the size of double bubble is different,the smaller bubble is suppressed stronger,and its change of temperature is more obviously.When the distance of double bubble increased from 100mm to 1cm,the secondary Bjerknes force decreases from 10^-4N to 10^-8N.The coupling double bubbles with different noble gas have shown different vibration patterns with clearly in the stage of rebound.Finally,Saturated argon and helium were dissolved in a 85%phosphoric acid solution and the spectra of the MBSL in the solution were measured using a photomultiplier tube and LN₂ CCD.The very clear 4s-4p configurational transition of argon atoms was observed in the argon-dissolved phosphoric acid solution,which was first measured in phosphoric acid solution and is a strong evidence for the theory of plasma nuclei in sonoluminescence.Also in the solution of helium dissolved in phosphoric acid solution,observed the OH ion spectrum,which is consistent with the results obtained by the suslick team.In both spectral data,a discrete spectrum was found around 590 nm.The analysis of spectral data shows that this is the atomic radiation spectrum of argon and helium.