Dynamic modeling of stepwise internal transport barrier formation in DIII-D negative-central-shear discharges.
The GLF23 transport model is used to dynamically follow bifurcations in the energy and toroidal momentum confinement in DIII-D discharges with an internal transport barrier. The temperatures and toroidal velocity profiles are evolved while self-consistently computing the effects of E x B shear stabilization during the formation and expansion of internal transport barriers. The barrier is predicted to form in a stepwise fashion through a series of sudden jumps in the core-electron and ion temperatures and toroidal rotation velocity. These results are consistent with experimental observations. In the simulations, the step transitions are a direct result of local E x B driven transport bifurcations.
Kinsey
J E
JE
Lehigh University, Bethlehem, Pennsylvania 18015, USA.
Staebler
G M
GM
Burrell
K H
KH
Austin
M E
ME
Waltz
R E
RE