Intermittent events and structure propagation in plasma turbulence [Elektronische Ressource] / vorgelegt von Thomas Windisch

Intermittent events and structure propagationin plasma turbulenceI N A U G U R A L D I S S E R T A T I O NzurErlangungdesakademischenGradeseinesdoctorrerumnaturalium(Dr. rer. nat.)anderMathematisch NaturwissenschaftlichenFakult at¨derErnst Moritz Arndt Universit at¨ GreifswaldvorgelegtvonThomasWindischgeborenam15.04.1978inBerlinGreifswald,imMarz¨ 2007Dekan: Prof. Dr. K.Fesser1. Gutachter: Prof. Dr. T.Klinger2. Gutachter: Prof. Dr. U.StrothTagderPromotion: 4. Mai2007AbstractTurbulenceisanomnipresentphenomenoninnature. Itsmaincharacteristics,fluctuationsunderawidespreadofspatialandtemporalscales,areobservedinneutralfluidorgaseoussystemsaswellasinplasmas. Althoughtheelectromagneticcharacterofaplasmamakesplasma turbulence more complex, the basic features of turbulence are universal. In mag netically confined plasmas, fluctuating plasma parameters give rise to turbulent transportofplasmaparticlesandenergy,whichdegradestheconfinementandaffectskeyissuesoffuture fusion devices. The intermittent character of this convective particle flux is asso ciated with high amplitude turbulent structures, called ”blobs”, propagating radially out wardsacrossthemagneticfield. Alsotheintermittentfluctuationsobservedintheplasmaedge of devices with linear magnetic field geometry seem to be related to propagatingturbulent structures. The mechanism of the radial propagation is however poorly under-stood.