Impurity Seeding of JET L–mode Diverted Plasmas with q(0)> 1

Impurity seeding of plasma discharges has led to regimes of improved thermal and parti-cle confinement in many tokamaks [1]. Extending these results to a larger device such as the JET tokamak allows size scaling and the evaluation of the potential of this approach to future fusion reactors. In the initial JET experiments reported here, neon impurity seeding produced modest increases in thermal energy confine-ment, H89P <1.4, a reduction in the thermal diffusivity, χi, and increases in the thermal neutron rate of more than a factor of 2, ac-companied by a large increase in radiated power, Prad/Pin <0.6. Gyrokinetic simulation(GKS) code simulations show a decrease in the growth rate of low k modes in discharges with impurity injection, consistent with a reduction in ion temperature gradient (ITG) modes. Two discharges with neon impurity in