Plasma size scaling of avalanche-like heat transport in tokamaks

Jolliet, S.; Idomura, Yasuhiro   

In this work, the dependence of turbulent ITG transport on plasma size is analyzed using the GT5D code. The implementation of a straight-field-line solver is presented, which enables drastic memory reduction and does not affect the steady state of nonlinear simulations. Plasma-size scaling simulations exhibit Bohm-like, or even worse-than-Bohm scaling. The latter is due to the link between parallel momentum and radial electric field profiles via the force balance relation. This suggests a close coupling between momentum and heat transport.