Category Archives: 内部研讨报告
题 目：托卡马克低–高模转换的理论及进展 （下载章扬中老师5月20日讲义）
时 间： 2014年5月20日（星期二） 14:00—16:00
地 点： 4号楼6楼中间会议室
- 轴对称环状静电模的漂移波湍流参量激发（物理学报，2014，63, 035202）
报告人： Dr. Bruce Scott
Max-Planck-Institut für Plasmaphysik
时 间：2014年5月19日（星期一） 14:00—16:00
This is an introduction to turbulence generally and turbulence in magnetised plasmas specifically. Turbulence is a statistical phenomenon involving interactions between many degrees of freedom, usually manifested as vortices or eddies at a wide range of scales. In fluids, the motion is mostly of the shearing type and the basic models are homogeneous and incompressible. In the presence of a gradient, the turbulence itself can still be treated as homogeneous and the gradient as a drive, or “stirring,” mechanism. The basic picture is called a “cascade” due to the fact that the stirring injects energy at large scale, and the eddies pass energy successively to slightly smaller eddies, and so on down to small scales at which it is consumed by diffusive or viscous dissipation. Homogeneous turbulence involves quadratic nonlinearities which interact through a large set of three wave combinations, a result following from the properties of Fourier transforms. The various three wave triads are expected to be statistically independent, which gives the turbulence its basic character. Fluid turbulence is kept incompressible by the pressure, and MHD or magnetised fluid turbulence is kept so by the magnetic field.
2014 年5月12号 五室第三十九期研讨会报告 The L-H transition on East
报告人： Prof. Jan Weiland12
1 Chalmers University of Technology, Sweden and EURATOM-VR
Association, Gothenburg, Sweden
2 Presently guest professor at ASIPP, Hefei, China
We have simulated the L-H transition on the EAST tokamak using a predictive transport code where ion and electron temperatures, electron density and poloidal and toroidal momenta are simulated self consistently. This is, as far as we know, the first theory based simulation of an L-H transition including the whole radius and not making any assumptions about where the barrier should be formed. The L-H power threshold increases with the temperature at the separatrix. This is why the power threshold increases linearly with the magnetic field in agreement with the threshold on C-mod. The values of the αmhd and αdia, as defined by Rogers, Drake and Zeiler 1998, have been found to be in the H-mode regime of their turbulence simulations in the H-mode barrier. The power used in EAST was found to be about 20% above the threshold for the L-H transition.