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能源是社会发展的基石。古人伐木为薪,后来柴薪逐渐被煤、石油、天然气等化石燃料取代。而今,化石能源面临“危机”,同时又对环境造成严重污染。以煤炭、石油、天然气等化石能源替代柴薪的第一次能源革命,带来了社会、经济的飞速发展。然而这些宝贵的化石能源是不可再生的,据估 相似文献
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分析了电子束入射托卡马克等离子体表面后所发生的一系列物理过程,特别是电子束注入等离子体后在边界层形成平行电流和径向负电场,使等离子体由低约束模式向高约束模式,即L H模式转换中的作用。论证了当注入电子束的密度超过一定的阀值时,L H 模转换被触发。 相似文献
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The cross-field diffusion coefficient (D_⊥) at the edge in the HT-7 tokamak is close to the Bohm value when the line average electron density ranges from 1.5×10^{19} to 3.0×10^{19}m^{-3}. The energy profile of the particles is derived directly from the H_α(D_α) line shape; the dissociative excitation of molecules is dominating when the local electron temperature is above 10eV. By means of the Monte Carlo method the D_α line shape is also simulated. We find that the molecular dissociation contributes to 57% of neutral atoms and 53% of emission intensity in front of the limiter, and 85% of neutral atoms and 82% of emission intensity in front of the wall. The influence of atomic and molecular processes on the energy balance is discussed for the scrape-off layer (SOL), and the power loss from molecular dissociation is found to be 6×10^4kW at the SOL. The ion Bernstein wave (IBW) can effectively suppress the magnetohydrodynamic behaviour, the fluctuation levels and the turbulence; the D_⊥ in front of the limiter declines from 0.84 to 0.2m^2·s^{-1} and the particle confinement time rises from 9 to 12ms. 相似文献
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Experimental Phenomena of Improved Ohmic COnfinement Induced by Modulated Toroidal Current on the HT—7 Tokamak 下载免费PDF全文
The phenomena of improved ohmic confinement have been observed during the modulation of the toroidal current on the Hefei superconducting Tokamak-7(HT-7).In the experiment,the programming ohmic heating field was modulated.A toroidal frequency-modulated current induced by modulated loop voltage was added on the plasma equilibrium current.The ratio of ac amplitude of the plasma current to the main plasma current is about 12-30%.These improved plasma confinement phenomena include the facts that the average electron density and the central electron temperature both increase,the Dα radiation from the edge is reduced,the magnetohydrodynamics is obviously suppressed by oscillating plasma current,and the global energy confinement time increases by 27-45%.It is found that the faster the modulation is,the more effective the improved ohmic confinement phase. 相似文献
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在HT-7装置实验研究中,利用主动反馈调制低杂波(LHW)实时有效地抑制了MHD不稳定性。介绍了用DAQ2010高速采集卡为硬件的系统对HT-7装置实验中MHD的实时检测和控制。 相似文献
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Dynamic Stabilization by Modulated Toroidal Current on the HT—7 Superconducting Tokamak 总被引:2,自引:0,他引:2 下载免费PDF全文
The technique of toroidal current modulation has been successfully used in suppressing magnetohydrodynamic (MHD) perturbations effectively on the HT-7 superconducting tokamak.When the ratio of amplitude of plasma modulated current ΔIp versus the equilibrium plasma current Ipo is about 12-30%,the resonance surface is moved outside the island width,and the suppression of MHD perturbations is observed.The disruption induced by tearing mode intability is delayed or avoided.Different formats of frequency modulated are compared. 相似文献
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