Fast-ion transport and neutral beam current drive in ASDEX upgrade

Fast-Ion Transport Induced by Alfven Eigenmodes in ASDEX Upgrade

A comprehensive suite of diagnostics has allowed detailed measurements of the AE spatial structure and subsequent fast-ion transport. RSAEs and TAEs have been driven unstable by fast-ions from ICRH as well as NBI origin. In ICRF heated plasmas, diffusive and convective fast-ion losses induced by AEs have been characterized in fast-ion phase-space. While single RSAEs and TAEs eject resonant fast...

Fast Ion Loss Diagnostic in ASDEX Upgrade

The confinement of fast particles is of crucial importance for next step fusion devices like ITER. Since fast ion losses might reduce the core heating and, in addition, cause untolerable first wall load, it is important to understand and possibly avoid them. Here, an integrated approach is presented for the analysis of neutral beam injection related fast ion losses in ASDEX Upgrade. It consists...

Ion orbit loss current in ASDEX Upgrade

The orbit loss current is calculated for the ASDEX Upgrade geometry using the 5D (3D in configuration space and 2D in velocity space) Monte Carlo code ASCOT. The balance between the obtained current and the analytical estimate of the return current shows an L–H transition for the normalized collision frequency ν∗i ≈ 1 as expected from analytic theory. The transition in ASDEX Upgrade, however, o...

Fast-ion D-alpha measurements at ASDEX Upgrade

MHD induced Fast-Ion Losses on ASDEX Upgrade

The interplay between MHD instabilities and energetic ions is of crucial importance for a safe plasma performance in self-heated fusion experiments like ITER. A detailed knowledge of the underlying physics has been gained from direct measurements of MHD induced fast-ion losses (FIL). Time resolved energy and pitch angle measurements of FIL correlated in frequency and phase with Neoclassical Tea...