Abstract
Measurements of the spatial structure of the transport coefficients of He2+ on the Tokamak Fusion Test Reactor is reported. He2+ profiles were measured using charge-exchange spectroscopy after a helium puff into corotating L-mode plasmas. Modeling shows that the He2+ diffusivity is about 10 m2/s near the plasma edge and drops to below 1 m2/s inside of the q=1 surface. The convective velocity ranges from 13 m/s near q=1 to 2040 m/s near the edge. The helium diffusivity is on the order of the ion momentum and thermal diffusivity and is greater than the electron thermal diffusivity.
Original language | English |
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Pages (from-to) | 2255-2258 |
Number of pages | 4 |
Journal | Physical Review Letters |
Volume | 65 |
Issue number | 18 |
DOIs | |
State | Published - 1990 |