排序方式: 共有34条查询结果,搜索用时 15 毫秒
31.
Heidbrink WW Gorelenkov NN Luo Y Van Zeeland MA White RB Austin ME Burrell KH Kramer GJ Makowski MA McKee GR Nazikian R;DIII-D team 《Physical review letters》2007,99(24):245002
Neutral-beam injection into plasmas with negative central shear produces a rich spectrum of toroidicity-induced and reversed-shear Alfvén eigenmodes in the DIII-D tokamak. The first application of fast-ion D_{alpha} (FIDA) spectroscopy to Alfvén-eigenmode physics shows that the central fast-ion profile is anomalously flat in the inner half of the discharge. Neutron and equilibrium measurements corroborate the FIDA data. The current density driven by fast ions is also strongly modified. Calculations based on the measured mode amplitudes do not explain the observed fast-ion transport. 相似文献
32.
Takechi M Matsunaga G Aiba N Fujita T Ozeki T Koide Y Sakamoto Y Kurita G Isayama A Kamada Y;JT- team 《Physical review letters》2007,98(5):055002
The plasma rotation necessary for stabilization of resistive-wall modes (RWMs) is investigated by controlling the toroidal plasma rotation with external momentum input by injection of tangential neutral beams. The observed threshold is 0.3% of the Alfvén velocity and much smaller than the previous experimental results obtained with magnetic braking. This low critical rotation has a very weak beta dependence as the ideal wall limit is approached. These results indicate that for large plasmas such as in future fusion reactors with low rotation, the requirement of the additional feedback control system for stabilizing RWM is much reduced. 相似文献
33.
Bindslev H Nielsen SK Porte L Hoekzema JA Korsholm SB Meo F Michelsen PK Michelsen S Oosterbeek JW Tsakadze EL Westerhof E Woskov P;TEXTOR team 《Physical review letters》2006,97(20):205005
Here we present the first measurements by collective Thomson scattering of the evolution of fast-ion populations in a magnetically confined fusion plasma. 150 kW and 110 Ghz radiation from a gyrotron were scattered in the TEXTOR tokamak plasma with energetic ions generated by neutral beam injection and ion cyclotron resonance heating. The temporal behavior of the spatially resolved fast-ion velocity distribution is inferred from the received scattered radiation. The fast-ion dynamics at sawteeth and the slowdown after switch off of auxiliary heating is resolved in time. The latter is shown to be in close agreement with modeling results. 相似文献
34.
YM Jeon JK Park SW Yoon WH Ko SG Lee KD Lee GS Yun YU Nam WC Kim JG Kwak KS Lee HK Kim HL Yang;KSTAR team 《Physical review letters》2012,109(3):035004
Edge localized modes (ELMs) in high-confinement mode plasmas were completely suppressed in KSTAR by applying n=1 nonaxisymmetric magnetic perturbations. Initially, the ELMs were intensified with a reduction of frequency, but completely suppressed later. The electron density had an initial 10% decrease followed by a gradual increase as ELMs were suppressed. Interesting phenomena such as a saturated evolution of edge T_{e} and broadband changes of magnetic fluctuations were observed, suggesting the change of edge transport by the applied magnetic perturbations. 相似文献