Results 261 to 270 of about 63,718 (300)

Thermal energy confinement properties of ELMy H mode plasmas in JT-60U

Nuclear Fusion, 2002
The dominant causes of the reduction in the enhancement factor of thermal energy confinement with increasing plasma density in ELMy H mode plasmas in JT-60U were analysed by separating the thermal stored energy into core and pedestal components.
H Urano, Y Kamada, H Shirai, T Takizuka, S Ide, T Fujita, T Fukuda   +6 more
openaire   +1 more source

Energy confinement of hydrogen and deuterium H-mode plasmas in JT-60U

Nuclear Fusion, 2012
Abstract Energy confinement properties for hydrogen and deuterium H-mode plasmas are investigated. The thermal energy confinement time becomes longer in deuterium by a factor of ∼1.4 than in hydrogen at a given absorbed power. When the absorbed power is fixed, the values of electron temperature T e and ion temperature T
H. Urano, T. Takizuka, T. Fujita, Y. Kamada, T. Nakano, N. Oyama   +5 more
openaire   +1 more source

Thermal energy confinement of high-triangularity ELMy H-mode plasmas in JT-60U

Plasma Physics and Controlled Fusion, 2001
High-triangularity ELMy H-mode experiments (δx~0.45) have been carried out in JT-60U. In the low-density regime (e/nGW 0.5), at fixed neutral beam heating power type-III ELMs are generated and the pedestal pressure reduces gradually with density whereas the ELM frequency at low triangularity is much lower at a given density.
H Urano, Y Kamada, H Shirai, T Takizuka, H Kubo, T Hatae, T Fukuda   +6 more
openaire   +1 more source

Decoupling the effects of plasma current and plasma density on DIII-D H mode energy confinement

Nuclear Fusion, 1994
Experiments that decoupled H mode plasma current and plasma density have been performed for the first time on the DIII-D tokamak by the application of divertor cryopumping. Deuterium ELMing H mode discharges were operated in the single null configuration with 6 MW of neutral beam injection. These steady state discharges were operated at 1.5 and 0.75 MA
D.P Schissel, M.A Mahdavi, J.C DeBoo, M Le   +3 more
openaire   +1 more source

Time evolution of transport properties in JT-60U H-mode plasmas with improved core confinement

Plasma Physics and Controlled Fusion, 1996
The time evolution of confinement and transport properties of ICC H-mode plasmas in JT-60U has been studied. We found the change of confinement character on a timescale much smaller than the thermal energy confinement time, , at the L - H and H - L transitions. A slow change on a timescale of is also found during the H-mode phase.
H Shirai, T Takizuka, Y Koide, Y Kamada, S Ishida, M Mori, O Naito, M Sato, N Isei, T Fukuda, Y Kawano, T Hirayama, M Azumi   +12 more
openaire   +1 more source

Impurity screening in Ohmic and high confinement (H-mode) plasmas in the Alcator C-Mod tokamak

Physics of Plasmas, 1997
A series of experiments has been carried out to determine the relative screening of the low recycling gaseous impurities, nitrogen and methane, in Alcator C-Mod tokamak [Phys. Plasmas 1, 1511 (1994)] discharges. The impurity density in the core plasma is directly proportional to the rate of impurity injection.
G. M. McCracken, B. Lipschultz, B. LaBombard, J. A. Goetz, R. S. Granetz, D. Jablonski, S. Lisgo, H. Ohkawa, P. C. Stangeby, J. L. Terry, and the Alcator Group   +9 more
openaire   +1 more source

H mode power threshold and confinement in JET H, D, DT and T plasmas

Nuclear Fusion, 1999
The scaling of both the L-H threshold and confinement with the mass M of hydrogenic isotopes is discussed. The confinement was found to scale differently with M in the core and the edge, and a two region model has been developed to represent the physical behaviour of each region.
openaire   +2 more sources

Degradation of energy and particle confinement in high-density ELMy H-mode plasmas on JT-60U

Plasma Physics and Controlled Fusion, 1997
Degradation of energy and particle confinement was investigated with a high-recycling divertor in ELMy H-mode plasma on JT-60U with high-power neutral beam injection of 18 - 19 MW; the plasma parameters were fixed at . The reduction in global energy confinement time was due to a reduction in the stored energy of fast ions with increasing plasma ...
N Asakura, K Shimizu, H Shirai, Y Koide, T Takizuka   +4 more
openaire   +1 more source

Hydrogen isotope effects on ITG scale length, pedestal and confinement in JT-60 H-mode plasmas

Nuclear Fusion, 2013
The dependence of heat transport, edge pedestal and confinement on isotopic composition was investigated in conventional H-mode plasmas. Identical profiles for the electron density, electron temperature and ion temperature were obtained for hydrogen and deuterium plasmas, whereas the required power clearly increased for hydrogen, which resulted in a ...
H. Urano, T. Takizuka, N. Aiba, M. Kikuchi, T. Nakano, T. Fujita, N. Oyama, Y. Kamada, N. Hayashi   +8 more
openaire   +1 more source

Improved confinement in high-density H-modes via modification of the plasma boundary with lower hybrid wavesa)

Physics of Plasmas, 2015
Injecting Lower Hybrid Range of Frequency (LHRF) waves into Alcator C-Mod's high-density H-mode plasmas has led to enhanced global energy confinement by increasing pedestal temperature and pressure gradients, decreasing the separatrix density, modifying the pedestal radial electric field and rotation, and decreasing edge turbulence.
J. L. Terry, M. L. Reinke, J. W. Hughes, B. LaBombard, C. Theiler, G. M. Wallace, S. G. Baek, D. Brunner, R. M. Churchill, E. Edlund, P. Ennever, I. Faust, T. Golfinopoulos, M. Greenwald, A. E. Hubbard, J. Irby, Y. Lin, R. R. Parker, J. E. Rice, S. Shiraiwa, J. R. Walk, S. J. Wukitch, P. Xu   +22 more
openaire   +1 more source