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1、中國科學(xué)技術(shù)大學(xué)博士學(xué)位論文正電子湮沒多參數(shù)測(cè)量系統(tǒng)研制姓名:孔偉申請(qǐng)學(xué)位級(jí)別:博士專業(yè):粒子物理與原子核物理指導(dǎo)教師:周先意;葉邦角20040501lFIUr湮沒多參數(shù)測(cè)量系統(tǒng)Ⅲ制中閏科學(xué)技術(shù)人學(xué)悻簞l-學(xué)世論之作為研究缺陷類型的例子。第四章主要介糾了壽命-動(dòng)量關(guān)聯(lián)測(cè)姑系統(tǒng),井詳細(xì)討論了計(jì)數(shù)率對(duì)能譜譜形的影響以及對(duì)麻的改進(jìn)上作,測(cè)量的實(shí)例是碳納米管材料。互I!£塑鯊蘭莖塑型墅墨竺業(yè)型!旦型蘭絲查苧蘭堡!:蘭絲笙墨AbstractThePAS(PositronAnnihilationSpectroscopy),asaco
2、mmonmethodtostudythestructureofmaterials.hasitsinbornadvantageinthestudyofdefectsinsolids.‘Originally,thePASincludesPAL(positronannihilationlifetimespectroscopy),DEBS(Dopplerbroadeningenergyspectrum,orDBAR,DopplerBroadeningAnnihilationRadiation),ACAR(Angularcorre
3、lationofannihilationradiation).AfterthegreatadvancingofPASin1960s’,researchersdon’tfeelthesetechniquesareenough,andtheybegintofindothermethodstostudythematerialswithpositron.Aftertheireffort,newtechniquesappeared,suchas2D·DBAR(2-DetectorDopplerBroadeningAnnihilat
4、ionRadiation),AMOC(Age—MomentumCoincide,AMOC),PAES(PositronAnnihilationinducedAugerElectronSpectroscopy),etc.Becauseofthedifficultytorealizethesesystems,thereislittleattentiononthesetechniquesintheirfirstyears.In1990’s,aftertheinprovementoftheelectronictechnique,
5、manysystemsarerealized,andplayimportantrolesinstudyofdefectandthestructureofmaterials.Inthesemethods,themulti—parametermeasurementsystem,suchas2D·DBARandAMOC,cangetabundantinformationinmaterials.The2D—DBARisusedinthefieldofelementalspecificityandstudyofthechemica
6、lenvironmentintheannihilationsite,andAMOCcanbeusedtostudytheformationandannihilationofpositronium,thetranslationofdifferentstate.Thesetwomethodscanhelpustodiscovermoredetailsinmaterials.DigitaltechnologyisbeWidelyusedinnuclearphysicsandpaticlephysics.Today,weCall
7、processdigitalpulsedirectlyowetotheimprovementofdigitaltechnology.Thesedigitalmethods,especiallythedCFD,areusedinPALandTOFspectrometersuccessfully.ItwillbenefitPAStousemulti—parametermeasurementanddigitaltechnology.Anew2D·DBARsystemissetupforadvancedstudyindefect
8、sofmaterialsandanoriginalmodelofAMOCissetupdependingontheexperienceofbuilding2D—DBARsystemThedifferencebetweenthesetwosystemsandsomeother2D·DBARandAMOCsystemsi