The mission of the spherical tokamak NSTX-U is to explore the physics that drives core and
pedestal transport and stability at high-and low collisionality, as part of the development of …

Spherical tokamaks are key to the successful design of operating scenarios of future fusion
reactors in the areas of divertor physics, neutral beam current drive and fast ion physics …

The sawtooth instability is known for inducing transport and loss of energetic particles (EPs),
and for generating seed magnetic islands that can trigger tearing modes. Both effects …

JET experiments have shown that the three-ion scenarios using waves in the ion cyclotron
range of frequencies (ICRF) is an efficient way to build fast ion population through beam ion …

Sawtooth crashes on tokamak plasmas exhibit relaxation much faster than resistive time
scales via a mechanism not fully understood. Using core magnetic measurements from the …

This presentation examines the energetic particle transport induced by saturated kink modes
and sawtooth crashes in JET deuterium plasmas. It is known that kink mode-resonant …

Internal kinks are a common magneto hydro-dynamic (MHD) instability observed in tokamak
operation when the q profile in the plasma core is close to unity. This MHD instability impacts …

It was recently shown that there exists a narrow parameter window where benign sawtooth
crashes cause only mixing of bulk plasma and slowed-down alpha particle'ash', while …

Off-axis sawtooth oscillations during the presence of nonlinear coupling between toroidal
Alfvén eigenmodes (TAEs) and tearing mode are firstly observed in the plasma without two …

We have investigated the role of the m/n= 2/1 neoclassical tearing mode (NTM) for
suppression of the sawtooth collapse in JT-60U from the viewpoint of the anomalous …