Transport and drift-driven plasma flow components in the Alcator C-Mod boundary plasma

PFC / JA - 96 - 23 Particle Drift Effects on the Alcator C - Mod Divertor

The sign of the toroidal magnetic field has a major effect on the divertor in Alcator C-Mod, determining whether the higher recycling is on the inboard or outboard side and leading to inboard/outboard temperature and density differences up to a factor of ten. A recently published paper [1] reported in detail on these observations, which are an indication of the importance of plasma particle dri...

PSFC / JA - 05 - 46 Advances in measurement and modeling of the high - confinement - mode pedestal on the Alcator C - Mod tokamak

Edge transport barrier (ETB) studies on the Alcator C-Mod tokamak [Phys. Plasmas 1, 1511, (1994)] investigate pedestal scalings and radial transport of plasma and neutrals. Pedestal profiles show trends with plasma operational parameters such as total current IP . A ballooning-like I2 P dependence is seen in the pressure gradient, despite calculated stability to ideal ballooning modes. A simila...

Evidence for electromagnetic fluid drift turbulence controlling the edge plasma state in the Alcator C-Mod tokamak

Magnetic topology effects on Alcator C-Mod scrape-off layer flow

Recent interest in the experimental study of tokamak plasma flow for different magnetic field geometries calls for theoretical understanding of the effects of tokamak magnetic topology changes on the flow. The consequences of total magnetic field reversal and/or X-point reversal on divergence-free plasma flow within magnetic flux surfaces is considered and the results are applied to interpret r...

Benefits and Challenges of the Use of High-Z Plasma Facing Materials in Fusion Devices

The use of high-Z plasma facing components requires intensive research in all areas, i.e. in plasma wall-interaction, in the physics of the confined plasma, diagnostic, and in material development. Only a few present day divertor tokamaks mainly Alcator C-Mod and ASDEX Upgrade gained experience with the refractory metals molybdenum and tungsten, respectively. ASDEX Upgrade was stepwise converte...