Le jeudi 19 janvier à 14h00 / Amphi 3, Centrale Marseille
Abstract : Nuclear fusion reveals as one of the most promising solutions in the current international situation of energetic crisis. In this context, the ITER project aims at proving the feasibility of nuclear fusion to produce energy. For this purpose, the fuel (called plasma) must be heated up to hundred million degrees. Such extreme conditions are required for the nuclear fusion reactions to take place. These reactions produce neutrons and alpha particles. The neutrons will leave the reactor and will be used to generate electricity as in present nuclear power plants. However, alpha particles (also called energetic particles, because they are born with energies of 3.5 MeV) must remain sufficiently well confined in the reactor in order to transfer their energy to the thermal particles and self-sustain this way the nuclear fusion reactions. Unfortunately, alpha particles have the capability to trigger Alfvén-like instabilities in the plasma, which can de-confine the particles and hence reduce the performance of fusion reactors. Other types of energetic particles can exist in a fusion reactor, coming from external heating (radio-frequency, energetic beams...).
The purpose of this presentation is to give a brief introduction to the general problem of energetic particles in fusion plasmas and how they can excite Alfvén-like instabilities. Afterwards, we will introduce the FAR3d project, an international network based on the development and use of the FAR3d code, used to model the physics of energetic particles and Alfvén instabilities by solving the magnetohydrodynamic (MHD) equations in the presence of energetic particles. Some results of the code are presented for different experimental fusion devices, highlighting the most relevant physics related to the presence of energetic particles. Such studies can be used to predict and optimise the heating in fusion plasmas.
Jacobo Varela Rodriguez is invited at M2P2 for one week by David Zarzoso Fernandez in the framework of their collaboration on the ANR project AIM4EP
Jacobo Varela Rodriguez Universidad Carlos III de Madrid - Research Group : Física de Plasmas