Investigation of Impurity Equilibrium at JET

摘要

It has been shown that neoclassical transport theory can describe heavy impurity transport in JET plasmas. In particular for the following features an explanation has been given : 1. Off-axis peaking of heavy impurities ( - > hollow background density profile) 2. Strong impurity-density asymmetry on magnetic surfaces ( - > centrifugal force) 3. Strong impurity flux in the first ms of impurity injection experiments in NBI heated plasmas (- > slow transfer of toroidal momentum between background ions and heavy impurities).