Dr
Amanda Hubbard
(Massachusetts Institute of Technology, Plasma Science and Fusion Center)
20/10/2016, 08:30
EXC - Magnetic Confinement Experiments: Confinement
Poster
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
Jinping Qian
(Institute of plasma physics, Chinese academy of sciences)
20/10/2016, 08:30
EXC - Magnetic Confinement Experiments: Confinement
Poster
Extension of large radius internal transport barrier (ITB), high bootstrap current fraction scenario toward low plasma rotation and q95 relevant to steady state operation at Q=5 in ITER has been successfully demonstrated in DIII-D. New DIII-D experiments have shown that the key feature of large radius ITB and excellent energy confinement when the scenario is extended inductively to higher...
Dr
C. Craig Petty
(General Atomics)
20/10/2016, 08:30
EXC - Magnetic Confinement Experiments: Confinement
Poster
A new regime with beta, collisionality and plasma shape relevant to the ITER steady-state mission has been attained in DIII-D using the fully noninductive hybrid scenario, including complete ELM suppression over a wide q_95 window (between 5.9 and 7.1) and with little confinement degradation using resonant magnetic perturbation (RMP) coils. Furthermore, high-beta hybrid plasmas have been...
Dr
Xi Chen
(General Atomics)
20/10/2016, 08:30
EXC - Magnetic Confinement Experiments: Confinement
Poster
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
Matthias Hirsch
(Max-Planck-Institut für Plasmaphysik)
20/10/2016, 08:30
EXC - Magnetic Confinement Experiments: Confinement
Poster
Wendelstein 7-X (W7-X) is built to assess the concept of optimized stellarators at reactor-relevant values of both collisionality and the plasma beta.
In its first operation phase (started in the end of 2015 for 10 weeks of plasma experiments), the device is equipped with five uncooled, inboard carbon limiters. This phase of the project is dedicated to integrated operation, commissioning and...
Mr
A. M. Garofalo
(General Atomics)
20/10/2016, 08:30
EXC - Magnetic Confinement Experiments: Confinement
Poster
Experiments on EAST [1] have started to adapt the fully-noninductive high poloidal beta scenario developed on DIII-D [2,3], in order to demonstrate, in principle, steady state tokamak operation at high performance on metal walls. The electron density is systematically varied in order to vary the deposition profile of the external lower hybrid current drive (LHCD), while keeping the plasma in...
Prof.
Satoru Sakakibara
(National Institute for Fusion Science)
20/10/2016, 08:30
EXS - Magnetic Confinement Experiments: Stability
Poster
Previous experiments in LHD show that high beta plasma with more than 5% was successfully achieved in the high collisional regime because of low magnetic field operation at 0.425 T. To investigate the collisionallity dependence of plasma confinement property, we have made high beta experiments in relatively high-field configurations at 1 T to increase the electron temperature. As a result,...
Dr
Hiromi Takahashi
(National Institute for Fusion Science)
20/10/2016, 08:30
PPC - Plasma Overall Performance and Control
Poster
In future reactors, the fusion reaction is expected to be sustained under the electron heating dominant condition, where both ion temperature and electron temperature are high. Thus the characterization of the thermal transport for the plasmas, of which ion temperature and electron temperature are simultaneously high, is necessary. In recent years, an integration of high ion temperature and...
Dr
Hajime Urano
(QST)
20/10/2016, 08:30
EXC - Magnetic Confinement Experiments: Confinement
Poster
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
Ian Chapman
(CCFE Fusion Association)
20/10/2016, 08:30
EXC - Magnetic Confinement Experiments: Confinement
Poster
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...
Dr
Costanza Maggi
(CCFE)
20/10/2016, 08:30
EXC - Magnetic Confinement Experiments: Confinement
Poster
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
Mike Dunne
(IPP-Garching)
20/10/2016, 08:30
EXC - Magnetic Confinement Experiments: Confinement
Poster
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...
