SRIM

SRIMASIPPSRIM程序介绍谭模强2005年6月1日SRIMASIPPoutline概括介绍SRIMSRIM的应用SRIMASIPPSRIMASIPPSRIMisagroupofprogramswhichcalculatethestoppingandrangeofionsintomatter。METHOD：Usingafullquantummechanicaltreatmentofion-atomcollisions.(SRIMalwaysreferestothemovingatomasanion,andalltargetatomsasatoms)SRIMASIPPSRIMconsistsoftwomainprograms,andseveralspecial-purposeprograms.SR(TablesofStoppingandRangesofionsinsimpletargets).quicklycreatesTablesofthestoppingandrangeofionsinmatteroverawidebandofionenergies.TRIM(theTransportofIonsinMatter)isaMonte-Carlocalculationwhichfollowstheionintothetarget,makingdetailedcalculationsoftheenergytransferredtoeverytargetatomcollision.(multi-layercomplextargets)SRIMASIPP蒙特卡罗模拟方法(M-C方法)通过计算机模拟跟踪一大批入射粒子的运动。粒子的位置、能量损失以及次级粒子的各种参数都在整个跟踪过程中存储下来,最后得到各种所需物理量的期望值和相应的统计误差。在M-C方法计算过程中采用连续慢化假设,即入射离子与材料靶原子核的碰撞采用两体碰撞描述,这一部分主要导致入射离子运动轨迹的曲折,能量损失来自于弹性能量损失部分,而在两次两体碰撞之间认为入射离子与材料中的电子作用连续均匀地损失能量,当入射为重离子时可认为在这期间入射离子作直线运动,能量损失来自于非弹性能量损失部分。两次两体碰撞之间的距离以及碰撞后的参数通过随机抽样得到。SRIMASIPPMonte-CarloTRIMisveryversatile:Itwillhandleionenergiesfrom10eVto2GeV/amu,andtargetswithuptoeightlayers,madeupoftwelvedifferentelements.Itwillcalculateboththefinal3Ddistributionoftheionsandalsoallkineticphenomenaassociatedwiththeion'senergyloss:targetdamage,sputtering,ionization,andphononproduction.Alltargetatomcascadesinthetargetarefollowedindetail.ThisprogramismoreaccurateincalculatingionrangesthanthetransportprogramusedintheSRprogramtoproducetherangetablesdescribedabove.SRIMASIPPStoppingpower:入射粒子在单位路程上损失的能量(-dE/dx).Range:入射粒子从进入靶起到停止点所通过的总的路程,称为射程.ProjectedRange:以Rp表示射程在入射方向投影的长度,称作投影射程.SRIM相关名词SRIMASIPP左边的示意图是一个能量E,有入射角的入射粒子在物质中的轨迹。是粒子在靶物质中所走过的路程，是与入射方向平行的射程，是与入射方向垂直的射程，与入射表面垂直的射程。pRpRpRtRSRIMASIPPIon:入射粒子Atom:靶原子Recoilatoms:与入射粒子发生位移碰撞的反冲靶原子Straggle:射程是具有统计性质的,不完全一致,而有小的统计变化Cascade:由于一个初级撞出原子而导至众多的原子发生位移的过程Vacancy:晶格中某个原子被移去后所形成的缺陷Interstitialatoms:填隙原子是指在正常排列的晶格原子位置之间插入的多余原子.BackscatteredIons:从入射表面进来又从入射表面出去的入射粒子TransmittedIons:从入射表面进来从背面出去的入射粒子Sputteredatoms:被入射粒子碰撞而离开入射表面的靶原子SRIMASIPPDisplacementCollisions:Theprocesswhereanenergeticincidentatomknocksalatticeatomoffitssite.ReplacementCollisions:Atomsiteswithnewatoms,identicaltotheiroriginalatom(thisisdiscussedbelow).Thisistheonlymechanisminwhichavacancymaybere-occupied.Ionization:isenergylosstothetargetelectrons.Theelectronsofthetargetabsorbenergyfromthefastmovingionsandrecoilatoms,andthenreleaseitasheatifthetargetisametal,orasphononsifthetargetisaninsulator.Phonons:areenergystoredinatomicvibrationsinacrystal.Sincealltheatomsinacrystalarelinked,whenyoustartvibratingoneofthem,thenalltheothersstartvibratingalso.Thismassvibrationisdescribedasaphonon,sinceitissomewhatquantized(certainvibrationmodesarepreferred).SRIMASIPPDisplacementEnergy():发生原子位移所必须的最小能量。LatticeBindingEnergy():Thisistheenergythateveryrecoilingtargetatomsloseswhenitleavesitslatticesiteandrecoilsinthetarget.Typicallyitisabout1-3eV,butvaluesarenotknownformostcompounds.SurfaceBindingEnergy():Thisistheenergythattargetatomsmustovercometoleavethesurfaceofthetarget(units=eV).FinalEnergy(ofamovingatom)():belowwhichitisconsideredtobestopped.FinalEnergyisanenergybelowanyoftheaboveenergies.dispElattEfinalEsurfESRIMASIPPAssume:incidentatomhasatomicnumber,energyE.collisionwithinthetargetwithanatomofatomicnumber.Afterthecollision,theincidentionhasenergyandthestruckatomhasenergy.1Z2Z1E2EIf,thenAtomicDisplacement,2EdispE1EdispEIf,thenvacancy,2EdispEIf,,=thenreplacementcollision,if,thenbecomesastoppedinterstitialatom.2EdispE1EdispE1Z2Z1Z2Z1ZIf,thenbecomesaninterstitialand+isreleasedasphonons,2EdispE1EdispE1Z1E2ESRIMASIPPDisplacements=Vacancies+ReplacementCollisionsVacancies=Interstitials+(Atomswhichleavethetargetvolume)入射粒子产生级联碰撞的示意图SRIMASIPP置换碰撞的示意图溅射的示意图SRIMASIPPSRIM的应用SRIMASIPP入射粒子的数据靶对象的数据（元素，原子质量，入射粒子能量范围）（元素，状态，原子质量，各成分所占比例）SRIMASIPP简单的介绍具体的数据可以根据需要求得入射粒子具体的能量对应的停止能量损失。SRIMASIPPTRIM具体的输入表格和菜单SRIMASIPP输入部分：入射粒子——NameMassEnergyAngleofIncidemce靶——LayernameWidthElements计算损伤类型:Quick:采用Kinchin-Pease模型来快速计算靶损伤情况8层,12种元素，不关注靶损伤的详细情况或者溅射。FullDamageCascade:该项跟踪每一个反冲核直到它们的能量低于靶原子的位移阈能.3层,4种元素。SRIMASIPP输出窗口SRIMASIPPTRIM的输出文件TRIMIndividualIonDataTableA1-RANGE_3D.TXT(Final3DIonDistribution)TableA2-BACKSCAT.TXT(BackscatteredIonKinetics)TableA3-TRANSMIT.TXT(TransmittedIonKinetics)TableA4-SPUTTER.TXT(SputteredAtomKinetics)TableA5-TRIMOUT.TXT(SummaryofTableA2-TableA4)TableA6-COLLISON.TXT(Ion-AtomCollisionKinetics)TableA7-COLLISON.TXT(withRecoilCascades)TableA8-COLLISON.TXT(withKinchin-PeaseDamage)SRIMASIPPAveragedTRIMOutputTableA9-TDATA.TXT(SummaryofCalculation)TableA10-RANGE.TXT(IonRangeDistribution)TableA11-LATERAL.TXT(IonRangeDistribution)TableA12-IONIZ.TXT(EnergyLosstoIonization)TableA13-PHONON.TXT(EnergyLosstoPhonons)TableA14-VACANCY.TXT(VacancyProduction)TableA15-NOVAC.TXT(ReplacementCollisions)TRIM的输出文件SRIMASIPP1.（Quick）快速计算一定能量粒子打进靶材料中的深度,入射粒子在靶物质中的分布，粒子的电离效应能量损失，传递给反冲原子的能量，背散射粒子数和穿透粒子数。2.（Full）计算入射粒子与靶原子的详细碰撞对靶物质的所有损伤。比如：溅射产额，入射粒子和反冲原子的能量损失详细情况。5.界面混合。3.构建复杂的分层，做高能粒子探测器。4.高能粒子慢化，根据入射粒子的能量和所需要的出射粒子的能量，精确的选定减速靶板的厚度。SRIMASIPP6.可以根据右图的数据估计入射