Conveners
Pedestal & ELM Physics: EX/3
- Philip B. Snyder (General Atomics)
Dr
Amanda Hubbard
(Massachusetts Institute of Technology, Plasma Science and Fusion Center)
19/10/2016, 14:00
EXC - Magnetic Confinement Experiments: Confinement
Oral
Significant progress has been made on Alcator C-Mod in expanding the configurations and conditions for which the I-mode regime can be accessed and maintained and understanding the physics which underlies the transport improvement. An important result from multidevice studies is that the power threshold for I-mode has only a weak dependence on BT, while the upper power limit increases with BT,...
Dr
Xi Chen
(General Atomics)
19/10/2016, 14:20
EXC - Magnetic Confinement Experiments: Confinement
Oral
In a recent discovery, the Quiescent H-mode (QH-mode) regime in DIII-D has been found to bifurcate into a new state at low torque in double-null shaped plasmas, characterized by increased pedestal height, width and global confinement [1, 2]. This provides an alternate path for achieving high performance ELM-stable operation at low torque, in addition to the conventional QH-mode operation...
Dr
Costanza Maggi
(CCFE)
19/10/2016, 14:40
EXC - Magnetic Confinement Experiments: Confinement
Oral
The H-mode pedestal structure is characterized in JET-ILW plasmas limited by type I ELMs. The pre-ELM pressure width Delta_p increases with the square root of beta_pol_PED, as assumed in EPED, in H-modes with low D gas injection. In dimensionless experiments Delta_p broadens at constant beta_pol_PED with increasing nu_star_PED. In power and gas scans Delta_p/sqrt(beta_pol_PED) is constant...
Dr
Hajime Urano
(JAEA)
19/10/2016, 15:00
EXC - Magnetic Confinement Experiments: Confinement
Oral
Here we report the global stabilization effect of Shafranov shift on the edge pedestal plasmas. Experimental observations show that (i) the increased Shafranov shift stabilizes the ballooning component of the peeling-ballooning mode (PBM) so that the edge pressure gradient is raised together with the expansion of the edge transport barrier (ETB) and (ii) when the Shafranov shift is fixed the...
Dr
Mike Dunne
(IPP-Garching)
19/10/2016, 15:20
EXC - Magnetic Confinement Experiments: Confinement
Oral
Scrape-off layer (SOL) properties are controlled by a number of parameters, such as heating power, main ion fuelling, and impurity seeding. The high field side high density (HFSHD) is a region of high density (~10× higher than the separatrix density) localised to the HFS SOL and is observed in both ASDEX Upgrade (AUG) and JET when a gas puff at sufficient heating power is applied. It can be...
Dr
Ian Chapman
(CCFE Fusion Association)
19/10/2016, 15:40
EXC - Magnetic Confinement Experiments: Confinement
Oral
The pedestal height has been significantly increased by optimising the plasma conditions at H-mode access in joint experiments in JET, ASDEX Upgrade, MAST and TCV. A predictive pedestal model has been developed negating the need to specify the global β and core density peaking. This model predicted that doubling the core pressure during the L-mode phase in JET would increase the pedestal...
