高功率激光誘導(dǎo)液本介質(zhì)產(chǎn)生等離子體的理論研究和實(shí)驗(yàn)測(cè)試.pdf

1、南京理工大學(xué)博士學(xué)位論文高功率激光誘導(dǎo)液本介質(zhì)產(chǎn)生等離子體的理論研究和實(shí)驗(yàn)測(cè)試姓名：李明申請(qǐng)學(xué)位級(jí)別：博士專業(yè)：儀器科學(xué)與技術(shù)指導(dǎo)教師：陸建201101Abstract博士論文Abstractnlephysicalprocessoflaserandliquidinteractionisinvestigatedandaphysicalmodelofthebreakdownthresholdforwaterisestablishednlec

2、auseofthediffractioneffectintheShadowgraphyandInterferometrycausedbylaserinducedshockwaveisanalyzed111emechanicaleffectsoflaserandtargetinteractioninwaterwerestudied111etrajectoryequationisderivedundergeometricalopticsap

3、proximationAnalysisoftheshieldingeffectofthelaserplasmaaswellastheexperimentandnumericalcalculationOilthecharacterparametersisdoneAtfirstbasedontherateequationoffreeelectrontwomodelstocalculatethedielectricbreakdownthres

4、holdofwaterareestablishedTheresultsshowthatthenumbercalmodelisclosertotheexperimentaldatathantheanalyticalmodel11leinfluenceonthebreakdownthresholdfrommultiphotonionizationavalancheionizationandcombinedlOSSofelectronsare

5、evaluatedOnnliSbasis，theevolutionoftheelectrondensityandtheabsorptioncoefficientandenergydensityoftheplasmaduringthelaserpulseweregottennecomparisonbetweentheoreticalthresholdandtheexperimentalbreakdownthresholdforwateri

6、nducedbypulselaserofdifferentwavebandindicatesthatthemodelisconsistent、析ththeexperimentalresultsinalargerangenemethodtoavoidthediffractioneffectintheShadowgraphyandInterferometrycausedbylaserinducedplasmaandshockwaveispr

7、oposed1f1圮phyrsicalmodelisestablishedaccordingtothefundamentaldiffractiontheoryandthephenomenonandinfluenceoflensdiffractionimagingeffectistheoreticallyderived，thustheconclusionthatwhenplasmaregionandcanlerahavetheobject

8、imagerelationship、析tlltheimaginglensthediffractioneffectcanbeovercomeissubstantiatedBythehighsensitivityopticaldetectiontechniquebasedonfibercouplingbeamdeflectionprinciple，theplasmashockwavegeneratedinthelaserablationon

9、AltargetunderwaterisinvestigatedItshowsthattheattenuationdistanceoftheplasmashockwaveaccrues、^，imtheincreaseoftheenergyofthelaserAnopticalfiberpressuresensorbasingonlightbeamdeflectionhasbeenusedtomeasurethepressureonthe