1053μm激光在腔靶中反常吸收和超热电子的研究

8219965HIGHPOWERLASERANDPARTICLEBEAMSVol.8,No.2May,19963863-416ICF1995329,199691411053Lm(,,52577,610003)19901993,É,X,SRS,,SRSRamanBrillouinABSTRACTWestudiedfullyandsystematicallythescalinglawsofvariousabnormalabsorptionsandpropertyofhotelectronsfor1.053Lmlaser-irradiatedhohlraumtargets,whichwereobservedwithvariousenergycalorimetersandspectrometersattheShenGuang-Éfa2cility,from1990to1994.Spectralcharacteristics,energyofvariousabnormalabsorptions,thehardXrayspectrumareobtainedinhohlraumtargets.TherelationofspectrumandenergyofSRS,temperatureandenergyofhotelectronversuslaserparametersandtargetstypearegiven.HotelectronsandSRScanbereducedobviouslyforshortlaserwavelenght.KEYWORDShohlraumtargets,abnormalabsorption,suprathemaleletrons,stimu2latedRamanscatteringandstimulatedBrillouinscattering0,,()()I=101431015Wöcm2L150Lm,:(RA)X0=XepXn02X0(1)Raman(SRS)X0=Xs+XepXn0ö4X0-(1ö2)X0(2)Brillouin(SBS)X0=XB+Xin0X0(3)(TPD)X0=XepX1+XepX0n0ö4(3ö2)X0(4)(IAD)X0=XepX+Xin02X0(5)ICF,:©1995-2005TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.,DT1,X,XThX,XG,É,11053Lm017110ns5605300Lm50700J1101431015Wöcm2fö117()()PT1SRSSBSCT128OMA1,SRSSBS;CT2048CCDOMA2,2X0(3ö2)X0Stokes;2X0(3ö2)X0;10(FF)115300keVX2211(1),1,SBSSRS,TPDRAIADSRS-up,:11053LmSBS,11351190LmSRS;01730.8LmSRS;RAIAD0153Lm2X0,TPD01709Lm(3ö2)X0(2)2(a)(),,,ncö4,SRS,(1170Lm1189Lm),(Au),2X02(b)CH(),CH,,,SRS(1155Lm),2X0,(3ö2)X0,(1ö2)X02121SBS(XianXBX0),,,11,4038©1995-2005TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.g1Theschematicvarietiesofabnormalabsorptionspectrarelativeintensity1Fig.2SRSandharmonicspectraofformvarfilm(0.3Lm)inhohlraumtargets(a)andformvarfilmplanartargets(b)2(a)(b)SRS5032:11053Lm©1995-2005TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.Brillouin,SBS20%30%,SRS23,RAIADTPDRaman,10%20%1Table1TypicalfractionofabnormalabsorptionspectraenergyinhohlraumsELöJSöpsSBSSRSTPD(32X0)RA,IAD(2X0)50085020%30%8%12%0.4%0.5%0.1%0.2%Fig.3RelationbetweenenergyofSRSlightassuprathermalelectron3SRS213,Lang2muir,,,(1)(2)(4)(5),Ehe,Raman(3)Manleg-Rowe,X0=Xs+Xpe(6),X0;XsRaman;XpeSRSLangmuirLangmuirSRSK1171Lm,Xs=0153X0,(6)Xpe=0147X0,2SRSLangmuir,ESRSmE2X0E(3ö2)X(1),SRS2X0(3ö2)X0,,ncö4,SRS,[1]:SRS214XMaxwell[2],MaxwellX,I0(E)=exp(a-bEx)(keVökeVõsr)(7),a;b,bö1=Th,(keV)X,4,Maxwell,10%15%6038©1995-2005TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.2EheESRSE2X0E(3ö2)X0Table2ComparisonbetweenEhewithESRSE2X0andE(3ö2)X0inthebohiraumEtaröJSNEheöJEpeöJESRSöJE2X0öJE(3ö2)X0öJ6611362416118128931612117361182818181524190186116111Te=212keV21Th=4311keV31Thh=19419keVFig.4SpectraofhardX-rayinsidehohlraumforK=11053Lm,ELS=582J,ELN=600J4X215SRS(EL,IK)(1)ESRSEheELESRSEheEL5(a)(b)ESRSEheEL:ESRSöJ=211exp(611Fig.5RelationbetweentheEhe(a)andESRS(b)ofinhohlraumtargetsandEL5Ehe(a)ESRS(b)EL10-3ELöJ),EheöJ=310exp(61010-3ELöJ)(2)ThILThIL6,,ThökeV=2919I0158ö1015(Wöcm2):11710141181015Wöcm2,ThLL,ILEThIL[3]7032:11053Lm©1995-2005TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.Fig.6RelationbetweentheThofinhohlraumtargetsandIL6ThIL(3)ESRSEheTh,(1260Lm)ThThhESRSEhx32keV114keV6718J010057J;(650Lm)ThThhESRSEhx1911keV92keV2311J0100223J:ESRSEheTh,ncö4;,SRS,ESRS:,560Lm5210LmSRS0106J111J,5400mm200mm5600mm200mmSRS1217J2310J:5400mm200mmSRS560200,5200SRS56020,SRSESRSEhe:EL,,SRS019%210%12%919%SRS3,SRS12,,ncö4,SRS,,ncö4,SRSESRSEheTh4,,,Th3SRSTable3ThecomparisonofthesuprathermalwithSRSfromhohlraumandplanartargetstargetmodelEtaröJILöWõcm-2EheöJESRSöJcavitytarget220194101411010197planartarget20312413101401080100324SRSTable4ThecomparisonofthesuprathermalelectronsandSRSforhohlraumunderdifferentlaserwavelenghEtaröJKöLmEhxömJThökeVESRSöJ2050153010351141001352631311053418271016193SRSSBS,TPD,RAIAD;SBS,(20%30%),;SRS,,ICF;SRS,SRS;EL400J,X(TeThThh),Maxwell;SRS;SRS8038©1995-2005TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.1KruerWL.PhysFluids,1991,B3(8):236023622KeithA.BrucecknerPhysicalReviewLetters,1976,37(18):6776793NishimuraH,AzechlHetal.Opticscommunications,1986,56(6):4094144KruerWL.Thephysicsoflaser-plasmainteractions(Addison-wesley,Menlopark,1988)5YongPEetal.PhysFluids,1990,B2(8)STUDYOFABNORMALABSORPTIONANDHOTELECTRONSFORHOHLRAUMTARGETSIRRADIATEDBY11053LmLASERLIGHTQiLanying,MeiQiyong,ZhaoXuewei,ZhengZhijian,LiSanwei,etalSouthwestInstituteofNuclearPhysicsandchemistry,LaboratoryforLaserFusion,No.77,P.O.Box525,Chengdu,610003StimulatedBrillouinandRamanscatteringareharmfultoplasmainstabilitiesbecauseoftheirpotentialtodecreasetheamountofenergydeliveredtothetargetandincreasethegenerationoffastelectronsandhardX-ray.TheycanplayasignificantdestructiveroleeveninX-raydrivenimplosion,astheycande2velopinthelongscalelengthplasmathatexpandsandfillsupthecavity.During1990to1994,westudiedalloutandsystematicallylawvarietiesofabnormalabsorptionandpropertyofhotelectronsproducedby1.053Lmlaserlight(IL=5101431015Wöcm2)irradiationhohlraumtargetsattheShenGuang-É.Theexperimentalresultshaveshow:StimulatedBrillouinscattering(SBS)andstimulatedRamanbackscattering(SRS)aremainabnormalabsorptionprocessesforhohlraumtargets,theycanscatterabout40%oftheincid