欢迎来到天天文库
浏览记录
ID:39256595
大小:667.53 KB
页数:3页
时间:2019-06-28
《multipacting英文学习材料》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、MultipactinginCoaxialWaveguideProblemDescriptionMultipacting,whichistheresonantbuildupofsecondaryelectrons,isoftenaconcerninradiofrequencystructures.Anytimeathereisanoscillatingelectromagneticfieldacrossagapbetweentwosurfacesthereexiststhepossibilitythatfortherightfieldamplitudeac
2、rossthegaparesonanceconditionwillexistallowingtheexponentialbuildupofsecondaryelectrons.Acoaxialwaveguideissuchstructurewheretheseconditionscanexist.InputFileFeaturesThesimulationsetupconsistsofacoaxialwaveguidewhereanelectromagneticwaveislaunchedatoneendandthenpropagatesdownthewa
3、veguideleavingthesimulationatanopenboundary.TheYeeelectromagneticmodel,alongwiththeDey-Mittracut-cellalgorithm,areusedtomodeltheelectromagneticsinthesimulation.Typicallythesimulationisrunoncewithoutparticlestodetermineanormalizationamplitudeforthewavelauncher.Thisallowsfollowingsi
4、mulationstorunwhereitiseasytospecifyaspecificwaveamplitude.Afterthewavehasbeenestablishedinthewaveguide,alineofseedelectronsisintroducedattheouterradiusofthecoaxeverytimestepforawavefullperiod.Thisinsuresthatallthephasesofthewavearecheckedformultipactingtrajectories.Variableweight
5、,taggedparticlesareused.Theparticleweightcorrespondstotheelectrongrowthalongtheparticletrajectoryandthetagallowsfortheuseofparticletrackinghistories.UsingthesecondaryelectronroutinesinVORPAL,everytimeanelectronimpactsthewaveguidewallswithanenergyinthecorrectrange,theywillproduceat
6、leastonesecondaryelectron.Insteadofproducingmoremacroparticlesinthesimulation,theelectronisre-emittedwithitsparticleweightmultipliedbythesecondaryelectronyield.Severalhistoriesareusedinthissimulation.Theelectricfieldissampledhalfwayacrossthegapnormaltotheamplitudeforthewavelaunche
7、r.APoyntingfluxhistoryrecordsthepowerbeingtransmitteddownthewaveguide.Thetrajectoryandinternalparticlevariablesarerecordedforasubsetofelectronsinthesimulations.Theparticleweightisthelastcomponentoftheinternalvariables.Monotonicgrowthintheparticleweightiswhatdemonstratesmultipactin
8、g.Tofindthesubsetoftheparticlestr
此文档下载收益归作者所有