Electron heating during ICRH in the JET tokamak is studied. Electron heating profiles are obtained by measuring the increase in electron temperature after sawtooth crashes. By studying the increase in electron heating during power ramp-up it is possible to distinguish direct electron heating from indirect electron heating via minority ions. For direct electron heating, power deposition profiles are obtained. For indirect electron heating, the time dependence is consistent with classical slowing-down of high energy ions on electrons through Coulomb collisions.
Modeling very high electron heating by radio frequency waves on EAST