Working meeting – Influence of suprathermal electrons on ionization, transport and radiation properties of fusion plasma with high-Z impurities

OPUS (NCN) – WORKING MEETING

March 31^th – April 01^th 2026

PAS Scientific Centre in Paris

Tokamaks represent currently one of the most promising options to achieve controlled nuclear fusion as a safe and abundant energy source. Unfortunately, the issue of plasma contamination by high-Z impurities like tungsten (W), due to wall erosion of the tokamak, is becoming a major source of concern for the stable and efficient operation of these fusion devices. Indeed, W impurities radiate significant energy from the plasma by X-ray radiation, which is detrimental for the fusion performance. A potential solution to mitigate W impurity accumulation in the plasma core is to apply central electron heating. However, in the presence of dominant electron heating, the electron velocity distribution function stops following a Maxwellian distribution and a significant suprathermal tail arises. Therefore, the main goal of this project is to investigate how a fast electron population can affect ionization, transport, and radiation properties of fusion plasma with high-Z impurities. This project will be part of the existing international collaboration with CEA IRFM, where the WEST tokamak is operated. The involved Polish and IRFM research teams will bring their complementary expertise in terms of theory, numerical modelling, analysis of simulation outputs, and experimental diagnostic data.

The aim of the event is to organize a working meeting of partners from France and Poland to discuss the current state of knowledge on this topic and the work plan for delivering the project’s objectives and outcomes. Several presentations by experts participating in the project are planned, followed by discussions and brainstorming sessions.

Institutions involved in the project:

• Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN), Krakow, Poland
• Institute for Magnetic Fusion Research (IRFM), French Alternatives Energies and Atomic Energy Commission (CEA), Cadarache, France
• Institute of Plasma Physics and Laser Microfusion (IPPLM), Warsaw, Poland
• National Centre For Nuclear Research (NCBJ), Otwock, Poland
• Nicolaus Copernicus University in Toruń (NCU), Toruń, Poland