H-mode Power Threshold Studies on MAST

H-mode Power Threshold Studies on MAST

H-mode Power Threshold Studies on MAST 150 150 UKAEA Opendata
UKAEA-CCFE-PR(19)67

H-mode Power Threshold Studies on MAST

Analysis of the L-H and H-L transition power thresholds (Pth) and pedestal parameters are presented for the Mega Ampere Spherical Tokamak (MAST). The dependencies of Pth on the average, core plasma electron density, X-point height and plasma current are described. Increasing X-point distance from the divertor floor over 10-12 cm, is found to increase Pth by a factor of three. The X-point height dependence of Pth is also observed to be sensitive to the plasma current; with an Ip decrease from 0.77 MA to 0.65 MA, also lowering Pth by a factor of three and increases the Pth roll-over X-point height by 3 cm. Finally, a comparison of the experimental results with the predictions by the Finite Beta Drift Wave model is made, which provides a remarkably clear condition for the transition into and out of the H-mode.

Collection:
Journals
Journal:
Plasma-- Special Issue “Magnetic Confinement Fusion”
Publisher:
MDPI (Multidisciplinary Digital Publishing Institute)
Published date:
16/10/2021