Fast Particle Excitation of TAEs in NSTX

Abstract

A broad spectrum of TAEs may be unstable in NSTX. TAEs are found having global radial structure. Alfven continuum gap exist even at high beta plasma, when TAE modes are present. TAEs may have strong drive {gamma}/{omega} > 30%, which requires developing of nonperturbative codes for more robust calculations. Single and two mode calculations predict highest beam ion losses totaling in high beta high-q{sub 0} plasmas {approximately} 30% of the NBI ion population with FLR effects included, where most of the losses are prompt losses (24%). Improved confinement (vs typical tokamak plasmas) is observed in high beta plasmas because of the presence of the magnetic field well and strong poloidal field at the edge. The results from START experiments need to be analyzed to provide the understanding of TAEs drive and damping in ST