Power exhaust control of a fusion reactor


Tokamak fusion reactors are being developed to facilitate mankind's transition to sustainable energy generation. In a tokamak, donut-shaped fusion plasma is confined by magnetic fields and heated to 10^8 K. The tokamak's exhaust pipe, the divertor, is exposed to conditions comparable to those on the surface of the Sun. This proposal aims to fully characterize for the first time the plasma in the divertor with an innovative imaging diagnostic. Using state-of-the-art real-time data analysis techniques, important parameters, such as the plasma temperature and the plasma geometry, shall be determined during an on-going experiment. With this information, new shapes for the divertor plasma will be controlled to minimize the heat loads on the walls.

The relatively cool (10^5 K) divertor plasma is not fully understood due to limited availability of diagnostic data. Line-radiation emitted by neutral and non-fully ionized particles leaves a footprint in the visible spectrum containing information on the local plasma parameters. By simultaneously imaging the divertor at a large number of wavelengths, key plasma parameters will be determined at high spatial resolution for the whole divertor at once. Real-time data processing will allow the information to be used for feedback-control. Two very promising new "advanced" divertor shapes (the Snowflake and X-divertor) were found to require feedback control of their geometry. This project will implement the necessary control system to perform the most accurate experiments to date on the exhaust-properties of these divertors.

I have established myself as an international expert on tokamak operations and advanced divertors by pioneering the production and characterization of all advanced divertors on the TCV tokamak. Coupled with my PhD in low-temperature plasma physics, I am in a unique position to make a very significant contribution to the advancement of my field. The proposed diagnostic should also find widespread use well outside the borders this field.


Project number


Main applicant

Dr. W.A.J. Vijvers

Affiliated with

Nederlandse Organisatie voor Wetenschappelijk Onderzoek, NWO-institutenorganisatie, DIFFER

Team members

Dr. W.A.J. Vijvers


16/01/2015 to 15/01/2018