Generation of suprathermal electrons during sawtooth crashes in a tokamak plasma

The acceleration of electrons during a sawtooth crash is demonstrated in various regimes of the TCV tokamak plasma. Simultaneous measurements of electron cyclotron emission from the low field side and from the high field side of the tokamak provide information on the fast electrons dynamics with a high resolution. The density, energy and effective radial diffusion coefficient of the suprathermal population are quantitatively reconstructed. The total kinetic energy of fast electrons generated during a sawtooth crash is comparable to the magnetic energy released during the crash.