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|Title:||Ion Cyclotron Resonance Heating Induced Transport in Stellarators and Other Asymmetric Toroids|
|Author(s):||Splitt, Edward Frank|
|Department / Program:||Nuclear Engineering|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||A Monte Carlo simulation is developed to model minority ion transport and fundamental ion cyclotron resonance heating (ICRH) in asymmetric magnetic field geometries. A discrete event model is used to superimpose resonance heated nonadiabatic changes in an ion's magnetic moment on a Coulomb scattering model that contains the Spitzer coefficients of drag, velocity diffusion, and pitch angle scattering (PAS). Ion drift orbit equations of motion are set in a magnetic flux coordinate system which separate fast motion along the field lines from slow motion across the lines.
The effects of ICRH on minority ion transport are investigated for helium-3 ions in stellarator plasmas. The energy distribution functions of these RF-heated ions develop high energy tails as a result of a preferential gain in velocity in the direction perpendicular to the ambient magnetic field. Estimates of neoclassical flux surface diffusion coefficients indicate that ion losses in a RF-heated stellarator plasma can be increased by as much as ten times non-ICRH ion losses. This can be attributed to an RF-increased fraction of trapped ions which results in increased neoclassical transport across the toroidal flux surfaces.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.
|Date Available in IDEALS:||2014-12-16|
This item appears in the following Collection(s)
Dissertations and Theses - Nuclear, Plasma, and Radiological Engineering
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois