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1.
The vacuum system of today's tokamak devices is designed to meet the operational requirements of the experiments. The operation can be divided into five modes, (1) pumping down and leak detecting of the vacuum vessel, (2) baking, (3) plasma-facing component (PFC) conditioning, (4)evacuating and controlling of the particles at plasma edge, (5) plasma discharge experiments. 相似文献
2.
SHI Yingtian SHI Bingren 《核工业西南物理研究院年报(英文版)》2004,(1):133-134
The safety most important factor profile is one of the the plasma discharge. For limiter configuration, people usually use the following cylindrical approximation formula to calculate it q(r)=5r^2BT/RIp where r is the minor radius of the plasma toms, R is the major radius (in m) , BT is the toroidal magnetic field (in T), Ip is the total toroidal current(in MA). 相似文献
3.
《等离子体物理论文集》2017,57(8):329-335
The impact of rough surface morphology on the angular distribution of eroded impurities has been investigated with the three‐dimensional (3D ) rough surface code SURO and a newly developed analytic model. The property of the rough surface structure can be described by the shadow angle of the rough surface in SURO , which is defined as the ratio of the horizontal characteristic length to the initial surface roughness. The SURO simulation results show that the influence of the rough surface on the angular distribution of eroded impurities comes into play when the shadow angle is larger than a threshold value. The larger shadow angle of the rough surface leads to a stronger shift of the angular distribution of the eroded impurities. Different rough surface topographies have been used in the SURO code to check the angular distribution of the eroded impurities. It is found that the shift tendency of the angular distribution is similar for different structures of the rough surface. Based on the numerical modelling results, an analytical model has been developed to investigate the impact of the shadow angle on the angular distribution of the eroded impurities, which shows the consistent result as the SURO simulations. 相似文献
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MPT-X是带4个内导体坏的托卡马克装置。本文用差分法计算了MPT-X磁偏滤器的平衡磁面位形。结果表明,迭加上各种强度的八极场都能形成磁偏滤器位形,形成电流的放电中心区域随八极场的增加而收缩。还模拟了从多极器运行模式向托卡马克的过渡。 相似文献
6.
Study of transport in the boundary layer of tokamak plasma in presence of magnetic divertors is extended to the second order
in ion collision frequency. Numerical results for ion and energy losses to the collector plates are presented for toroidal
and poloidal divertors. For the toroidal case, the Wiener-Hopf solution for the second order distribution function is obtained.
An error occurring in an earlier first order calculation is pointed out and corrected first order fluxes are also given. For
the poloidal divertor, asymmetry observed in ion and energy transport is found to persist in the second order result. 相似文献
7.
Study on divertor plasma behavior through sweeping strike point in new lower divertor on EAST 下载免费PDF全文
Yu-Qiang Tao 《中国物理 B》2022,31(6):65204-065204
A series of L-mode discharges have been conducted in the new ‘corner slot’ divertor on the Experimental Advanced Superconducting Tokamak (EAST) to study the divertor plasma behavior through sweeping strike point. The plasma control system controls the strike point sweeping from the horizontal target to the vertical target through poloidal field coils, with keeping the main plasma stability. The surface temperature of the divertor target cools down as the strike point moves away, indicating that sweeping strike point mitigates the heat load. To avoid the negative effect of probe tip damage, a method based on sweeping strike point is used to get the normalized profile and study the decay length of particle and heat flux on the divertor target λjs, λq. In the discharges with high radio-frequency (RF) heating power, electron temperature Te is lower and λjs is larger when the strike point locates on the horizontal target compared to the vertical target, probably due to the corner effect. In the Ohmic discharges, λjs, λq are much larger compared to the discharges with high RF heating power, which may be attributed to lower edge Te. 相似文献
8.
At DIII-D, a slot divertor concept, called small-angle-slot (SAS), is under development, aiming to enable detachment at relatively low plasma edge density. We report on simulations using the SOLPS-ITER two-dimensional edge code to examine the performance of conceptual “SAS 2” slot configurations. The focus of the analysis is on E × B drift effects on upstream density at detachment (UDD), with detachment marked by electron temperature Te ≤ 3 eV at the outer strike point (OSP). With toroidal field such that radial E × B drift carries particles from the OSP towards the private flux region (PFR), placing the OSP near the inner slot wall gives ≈20% lower UDD than having the OSP near the outer wall. The inner wall effectively traps the radial E × B drift flux, resulting in low Te and associated radial electric field in the PFR, and thus small losses from the slot to the inner target via poloidal E × B drift flux. With toroidal field reversed such that radial E × B drift is reversed, OSP placement near the inner wall gives ≈10% lower UDD than OSP placement near the outer wall. Although radial E × B flux is from the OSP towards the outer wall, this flux largely escapes the slot, raising the UDD. A change in the slot shaping is suggested with the goal of eliminating such E × B -driven particle losses from the slot. 相似文献
9.
I. Paradela Pérez M. Groth M. Wischmeier D. Coster D. Brida P. David D. Silvagni M. Faitsch the ASDEX-Upgrade Team the EUROfusion MST Team 《等离子体物理论文集》2020,60(5-6):e201900166
SOLPS-ITER L-mode-like simulations with the full set of currents and drift velocities activated, and fluid neutrals have been carried out to interpret experimental results obtained in AUG. Drifts are critical to quantitatively reproduce the experimental results; however, simulations without drifts can also reproduce some trends qualitatively. The magnitude and dependence of the peak heat flux onto both targets on the upstream collisionality are, in general, in quantitative agreement within uncertainties with infrared thermography measurements in favourable field direction. The onset of power detachment is observed. In unfavourable toroidal field direction, a more symmetrical inner/outer target solution with regards to the power distribution is predicted, in agreement with experimental observations. However, also in unfavourable toroidal field direction, insufficient power is dissipated in the simulations and therefore qpeak, inn is overpredicted by up to a factor of 4 and qpeak, out by up to a factor of 1.5. The largest contribution to the sources due to radial transport in the energy balance equation is the radial divergence of the energy flux due to VE × B. 相似文献
10.
A coordinate transformation technique between straight magnetic field line coordinate system (Ψ, θ) and Cartesian coordinate system (R, Z) is presented employing a Solov'ev solution of the Grad-Shafranov equation. Employing the equilibrium solution, the poloidal magnetic flux Ψ(R, Z) of a diverted tokamak, magnetic field line equation is solved computationally to find curves of constant poloidal angle θ, which provides us with explicit relations R = R(Ψ, θ) and Z = Z(Ψ, θ). Correspondingly, conversion from one coordinate to the other along particle trajectories in the vicinity of separatrix is demonstrated. Based on the magnetic structure, a finite element mesh is generated in a diverted tokamak geometry to solve Poisson's equation. 相似文献