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Author: Qingjiang Pan
Requested Type: Poster
Submitted: 2018-03-01 12:29:24

Co-authors: D. Told, E. Shi, G. W. Hammett, D. R. Ernst, F. Jenko

Contact Info:
77 Massachusetts Avenue
Cambridge, Massachuse   02139

Abstract Text:
Unique properties of plasmas in the tokamak edge, such as large amplitude fluctuations and plasma–wall interactions in the open-field-line regions, require major modifications of existing gyrokinetic codes originally designed for simulating core turbulence. To this end, the global version of the 3D2V gyrokinetic code GENE, so far employing a delta-f splitting technique, is extended to simulate electrostatic turbulence in straight open-field-line systems. The major extensions are the inclusion of the velocity-space nonlinearity, the development of a conducting-sheath boundary, and the implementation of the Lenard–Bernstein collision operator. With these developments, the code can be run as a full-f code and can handle particle loss to and reflection from the wall. The extended code is applied to modeling turbulence in the Large Plasma Device (LAPD), with a reduced mass ratio and a much lower collisionality. Similar to turbulence in a tokamak scrape-off layer, LAPD turbulence involves collisions, parallel streaming, cross-field turbulent transport with steep profiles, and particle loss at the parallel boundary. Very recently, we have formulated a new exact linearized gyrokinetic Fökker-Planck collision operator. The new operator is written in a conservative form for implementation in GENE using a finite-volume method. Work supported by U.S. DoE contract No. DE-AC02-09CH11466 and DE-FC02-08ER54966.