Details

Autor(en) / Beteiligte

• Groebner, R.J
• Baker, D.R
• Burrell, K.H
• Carlstrom, T.N
• Ferron, J.R
• Gohil, P
• Lao, L.L
• Osborne, T.H
• Thomas, D.M
• West, W.P
• Boedo, J.A
• Moyer, R.A
• McKee, G.R
• Deranian, R.D
• Doyle, E.J
• Rettig, C.L
• Rhodes, T.L
• Rost, J.C

Titel

Progress in quantifying the edge physics of the H mode regime in DIII-D

Ist Teil von

• Nuclear fusion, 2001-12, Vol.41 (12), p.1789-1802

Ort / Verlag

Bristol: IOP Publishing

Erscheinungsjahr

2001

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Edge conditions in DIII-D are being quantified in order to provide insight into the physics of the H mode regime. Several studies show that electron temperature is not the key parameter that controls the L-H transition. Gradients of edge temperature and pressure are much more promising candidates for elements of such parameters. They systematically increase during the L phases of discharges which make a transition to H mode, and these increases are typically larger than the increases in the underlying quantities. The quality of H mode confinement is strongly correlated with the height of the H mode pedestal for the pressure. The gradient of the pressure is limited by MHD modes, in particular by ideal kink ballooning modes with finite mode number n. For a wide variety of discharges, the width of the barrier for electron pressure is well described by a relationship that is proportional to ( beta super(p) sub(p) super(ed)) super(1/2). A new regime of confinement, called the quiescent H mode, which provides steady state operation with no ELMs, low radiated power and normal H mode confinement, has been discovered. A coherent edge MHD mode provides adequate particle transport to control the plasma density while permitting the pressure pedestal to remain almost identical to that observed in ELMing discharges.