Electron Cyclotron Resonance Heating (ECRH)

The electron cyclotron resonance heating (ECRH) heats (only) the electrons by radio wave heating. The radial position of the resonance layer ist determined by the elctron cyclotron frequency, f = 28 MHz/T. Due to the fact, that the magnietic field decreases with 1/R in a tokamak/stellarator, the ECRH heats the plasma very locally. For our system with a fixed frequency of 140 GHz, the deposition at 2.5 T is located exactly at the minor radius of ASDEX Upgrade.

During the experiments at ASDEX Upgrade the advantage of the local heating is used. The physical studies concentrates on

  • power modulation for transport studies
  • dependence of the temperature profile on the radial position of the deposition
  • investigations to MHD: influence and control of local heating / current drive on MHD instabilities
  • creation of reversed shear plasmas with off-axis heating in the current ramp up phase
  • influence of edge electron heating on the L-H transition
  • control of MARFE's