Speaker
Description
In magnetically confined fusion reactors, energetic ions must be kept well confined until they slow down to the plasma bulk through Coulomb collisions. Energetic ions are, however, subject to a wide variety of cross-field transport due to their large velocities, long mean free path and slowing down times. Indeed, a broad spectrum of magnetohydrodynamic (MHD) fluctuations have been observed to cause a significant fast-ion transport / loss degrading their heating and current drive efficiency as well as the machine integrity. In general, in the presence of MHD fluctuations, the fast-ion cross-field transport depends on the properties of the MHD wave and particle orbits, and more specifically, on the perturbation´s phase at the particle´s position at any time. To characterize, and better understand, the MHD induced fast-ion transport, and loss, the community has developed a broad set of fast-ion loss diagnostics with the goal of covering the largest particle phase-space volume with Álfvenic time resolution. As expected, however, the ideal fast-ion loss diagnostic does not exist, and a combination of diagnostics is normally used in present devices to measure fast-ion losses. In this talk, the most advanced techniques will be briefly introduced and their capabilities and prospects for present and future devices discussed.
