For one week, around fifteen participants from seven different nations, including three from ITER Organization, learned the intricacies of operating the WEST tokamak through a series of thirty theoretical courses and hands-on exercises in the control room.

A study carried out by CEA-IRFM researchers has confirmed that electron heating, which is predominant in ITER and fusion power plants, will be sufficiently efficient to also heat the ions and sustain the fusion reactions.

Equipped with superconducting coils and tungsten plasma-facing actively cooled components, the WEST tokamak has achieved a new plasma duration record of over 6 minutes, with a steady-state temperature of 50 million degrees Celsius (4 keV).

Tungsten, with its refractory properties and resistance to atomic sputtering, is chosen as the reference material for plasma-facing components in magnetic confinement fusion devices such as tokamaks. Subjected to intense flows of heat and particles, tungsten is nevertheless progressively eroded by the plasma.

In magnetic fusion devices, the components facing the plasma are subjected to energetic particle flows of ions or hydrogen (fuel) atoms and helium (the product of fusion reactions). The helium settles and aggregates in the form of nano-bubbles, which alter the properties of the material in question, such as tungsten.

One of the challenges in the development of fusion energy is the simultaneous achievement of high fusion power and its control over very long durations. This is one of the ITER missions addressed by WEST (France), and an essential step in the development of a fusion power plant providing stable electrical power to the grid.