TY  - JOUR
AU  - Reiser, D.
AU  - Eich, T.
TI  - Drift-based scrape-off particle width in X-point geometry
JO  - Nuclear fusion
VL  - 57
IS  - 4
SN  - 1741-4326
CY  - Vienna
PB  - IAEA
M1  - FZJ-2017-01944
SP  - 046011 -
PY  - 2017
AB  - The Goldston heuristic estimate of the scrape-off layer width (Goldston 2012 Nucl. Fusion 52 013009) is reconsidered using a fluid description for the plasma dynamics. The basic ingredient is the inclusion of a compressible diamagnetic drift for the particle cross field transport. Instead of testing the heuristic model in a sophisticated numerical simulation including several physical mechanisms working together, the purpose of this work is to point out basic consequences for a drift-dominated cross field transport using a reduced fluid model. To evaluate the model equations and prepare them for subsequent numerical solution a specific analytical model for 2D magnetic field configurations with X-points is employed. In a first step parameter scans in high-resolution grids for isothermal plasmas are done to assess the basic formulas of the heuristic model with respect to the functional dependence of the scrape-off width on the poloidal magnetic field and plasma temperature. Particular features in the 2D-fluid calculations—especially the appearance of supersonic parallel flows and shock wave like bifurcational jumps—are discussed and can be understood partly in the framework of a reduced 1D model. The resulting semi-analytical findings might give hints for experimental proof and implementation in more elaborated fluid simulations.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000405944200003
DO  - DOI:10.1088/1741-4326/aa5ab7
UR  - https://juser.fz-juelich.de/record/827856
ER  -