Study On Stimulated Raman Scattering In Water And Heavy Water By Laser-induced Plasma Shockwave

Water is the most common molecular compound, the research on which hasattracted more and more attention. Physical property of water under high temperatureand high pressure physics has been focus of study. Raman scattering spectra oftechnology is an effective tool for study on the structural properties of water. Waterdoes not have the surface Raman-enhanced effect, which to a large extent restricts ourstudy on Raman technology for water surface enhancement and also brings a lot ofobstacles to the Raman spectra collecting water and substances in it. Therefore, theresearchers used various kinds of ways to conduct a research of the stimulated Ramanscattering on water and substances in it. The research group made the experiments andrelevant study mainly by strong laser inducing plasma to enhance the stimulatedRaman scattering of water and heavy water.This paper makes an intensive study on the physical mechanism of strongplasma shock wave caused by high power pulse laser inducing liquid breakdown, andinvestigates the pressure and temperature characteristics of dynamic pressure fieldgenerated by plasma shock wave. According to the basic principle of stimulatedRaman scattering, water and heavy water were measured experimentally by using thehigh dynamic pressure technology produced by plasma shock wave, and both thephase information under dynamic pressure conditions and certain results wereachieved.(1). We use strong laser (above140mJ) induced breakdown to produce shockwave compression effect, obtaining in water the new stimulated Raman scatteringspectra line313cm-1, which basically anastomosed with the lattice vibration frequency320cm-1of VIII phase Tz (B1g)+Txy (Eg) of ice under7Gpas; laser inducedbreakdown effect resulted in plasma bubbles, during the expanding process of plasma bubbles inducing the electron beam injection and strong shock wave, the ice VIIIphase arising under shock wave compression, under the action of strong laser (above140mJ) the structure of water similar to the VIII phase of ice.(2). Under the action of the shock wave induced by strong laser pulse, theheavy water280cm-1crystal lattice translational stimulated Raman scattering wasobtained. The lattice translation and stimulated Raman scattering of internal modelproved in common that in heavy water the ordered ice VII phase in proton part wasproduced. Laser induced shock wave can be used to study the Phase transformation ofliquid, producing nano-level particles which can be used for cleaning of chip in thesemiconductor industry.Strong pulse laser induced liquid breakdown producing plasma shock wavefalls into the dynamic high-pressure research category, which provides a goodtechnical means for the study on substantial physical properties under dynamichigh-pressure environment. The results enrich the substantial phase transitionalstructure information under the condition of dynamic high pressure, expands theapplication field of the laser induced breakdown, and shows a broad applicationprospect for the dissociation, deposition and phase transformation of the fluidmolecules.