Ion cyclotron resonance heating and current drive in tokamaks
1998 (English)Doctoral thesis, comprehensive summary (Other scientific)
In this thesis numerical studies, performed with theMonte-Carlo code FIDO of the evolution of the resonant-iondistribution function in the presence of ion cyclotronresonance heating (ICRH) in toroidal geometry are presented. Inparticular it is pointed out how the absorption of toroidalmomentum from a wave field with finite parallel wave numberscauses spatial drift and diffusion, which together with thefinite orbit widths of the tail ions is shown to have a largeeffect on the temperature profile of the resonant ion speciesand also to cause losses of high-energy ions to the wall.Furthermore, it is found that the finite orbit width and theinward drift occuring for negative parallel wave numbers eachgive rise to a new mechanism of minority-ion cyclotron currentdrive (MICCD) as compared to earlier models where the driftorbits of the resonant ions are confined to the magnetic fluxsurfaces. For high levels of coupled power these new mechanismsare found to be the dominating ones.
Keywords: Tokamak, quasilinear Fokker-Planck equation,ion cyclotron resonance heating (ICRH), minority ion cyclotroncurrent drive, finite orbit width, wave-induced spatialdiffusion, Monte-Carlo method, orbitaverage
Place, publisher, year, edition, pages
Stockholm: Alfvénlaboratoriet , 1998. , 60 p.
IdentifiersURN: urn:nbn:se:kth:diva-2627ISBN: 91-7170-237-7OAI: oai:DiVA.org:kth-2627DiVA: diva2:8281
NR 201408052000-01-012000-01-01Bibliographically approved