2020年1月6日 五室第133期研讨会

202016 五室第133期研讨会

题  目: Prospect of plasma theory and simulation research for JA DEMO  ( Dr. YAGI Masatoshi)

  摘  要:In Japan, the Joint Special Design Team for Fusion DEMO contributes to develop JA DEMO as the national team. Recently, plasma theory and simulation working group has drawn up an intermediate term research plan to contribute the conceptual design of JA DEMO. In this presentation, we will briefly introduce the activity of plasma theory and simulation research for DEMO.

题  目: Interplay between fluctuation driven toroidal axisymmetric flows and resistive ballooning mode turbulence  Dr. SETO Haruki

摘  要:An interplay between fluctuation driven toroidal axisymmetric flows (

convective cell modes) and resistive ballooning mode turbulence after the pedestal collapse is numerically studied by a four-field reduced MHD model in the BOUT++ framework. The strong flow shear sup- presses the radial transport of pressure filaments, and the pressure profile in the pedestal region is partially recovered. As a result, a secondary instability is quasi-linearly excited, which yields a secondary collapse. The subsequent damped oscillation is also analyzed by phase diagram analysis.

题  目: Characteristics of ITG turbulence and associated global profile

formation in flux-driven gyrokinetic simulation ( Dr. WANG Wei)

摘  要:Global nature of multi-scale turbulence is of specifically importance in

understanding and evaluating transport levels in Tokamak plasmas. Based on flux-driven gyrokinetic simulations using GKNET, characteristics of ITG turbulence and associated global profile formation are discussed through several approaches including Fourier-based analyses and the newly developed size-PDF analysis

主持人: 项农

时  间:2019年1月6日(星期一)  14:00—16:30

地  点:4楼中间会议室 ~欢迎全所感兴趣的同志

2020年1月3日 五室第132期研讨会

202013 五室第132期研讨会

题目:First application of the self-consistently coupled full-wave/Fokker-Planck analysis for the modeling of the LHW experiment on EAST



   间: 2020年1月3日(星期五)  15:30—16:30



Lower hybrid wave is the most important auxiliary heating and current drive tool on EAST.  Both ray-tracing and full wave codes have been used to model the LHW physics for the EAST experiments. Recently the self-consistently coupled full-wave/Fokker-Planck analysis has been successfully carried out for this domain. The process of the iteration between the full wave code(TORLH) and the Fokker-Planck code(CQL3D) will be introduced. The results including the spectrums with poloidal broadening, the wave electric fields, the power density profiles and the electron distribution function will be presented..




        2019年12月5日我室召开2019年度职工工作总结会议,本次会议旨在回顾我室2019年度科研总体进展情况,同时部署2020年度的工作的重点 。



2019年12月27日 五室第131期研讨会

20191227 五室第131期研讨会

题  目:The simulation of plasma response to RMP in BOUT++ framework

报告人 桂彬

主持人: 杨程

时  间:2019年12月27日(星期五)  15:00—16:30

地  点:4楼中间会议室

  摘  要:

Resonant magnetic perturbations (RMP) have extensively been demonstrated as a plausible technique for mitigating or suppressing large edge localized modes (ELMs). The plasma response to RMP plays a key role in the suppression of ELM with RMPs. A linear model of plasma response is developed in BOUT++ framework. The penetration process of the resonant component of the radial magnetic field is achieved from the simulation. Also its dependence on resistivity and plasma rotation is also obtained.


2019年12月20日 五室第130研讨会

 目:Hybrid simulation of fishbone instabilities with reversed safety factor profile



 间:2019年12月20日(星期五)  14:30—15:30



Linear stability and nonlinear dynamics of the fishbone instabilities with reversed safety factor profile have been investigated by the global kinetic-magnetohydrodynamic (MHD) code M3D-K. For the consideration of the fishbone instability, there are two different types of the fishbone instability: dual resonant fishbone (DRF) with double q = 1 surfaces and non-resonant fishbone (NRF) with the minimum value of safety factor qmin a little larger than unity. Based on EAST-like parameters, linear simulations show that the DRF is excited by the trapped beam ions when the fast ion pressure increases to exceed a critical value, and the mode structure of DRF exhibits splitting feature due to double q = 1 surfaces. When qmin increases from below unity to above unity, the fishbone instability transits from the DRF to the NRF, and the mode frequency of the NRF is higher than the DRF as the NRF is resonant with fast ions with larger precessional frequency. Nonlinear simulations show that the saturation of the DRF is due to MHD nonlinearity with a large n = 0 component. However, the saturation of the NRF is mainly due to the nonlinearity of fast ions, and the frequency of the NRF chirps down nonlinearly. The fast ions are redistributed and become flattened due to the DRF or the NRF, and the transport level of the fast ions due to the NRF is weaker with more centrally radial redistribution region in comparison with the DRF.





2019年12月13日 五室第129研讨会

20191213 五室第129研讨会 

   目:3D Modeling of ICRF Coupling on EAST Tokamak



   间: 2019年12月13日(星期五)  15:00—16:30



Radiofrequency wave in ion cyclotron range of frequency (ICRF) is an important way for heating plasma, driving current and implementing plasma control in the magnetic fusion devices such as EAST and ITER tokamak. Achieving good coupling of ICRF power into the plasma is an essential issue for high power ICRF injection on EAST tokamak. In this talk, we present the Modeling of ICRF power injected into 3D EAST plasmas via the high performance Finite-difference time-domain (FDTD) model in VSim software. Realistic 3D ICRF antenna module and box of the B-port on EAST have been constructed as geometry in the simulations. The effects of antenna structure, antenna phase, minority ion, distance between antenna and plasma, and toroidal curvature on the ICRF coupling and propagation are discussed.


2019年12月6日 五室第128研讨会

2019126 五室第128研讨会 

  目:Recent progress in the development of gyrokinetic semi-Lagrangian code NLT



 间: 2019年12月6日(星期五)  15:00—16:30



Large-scale gyrokinetic simulation has become an indispensable tool to study low frequency phenomena in tokamak plasmas, including turbulence transport, zonal flows and energetic particle physics.  NLT is a 5D continuum gyrokinetic code based on the I-transform theory model. In this talk, a brief introduction to the basic gyrokinetic theory and simulation models will be given. Recent progresses in the code development, including multi-ion species, kinetic electrons and the hybrid spectral semi-Lagrangian method will be reported.


2019年11月29日 五室第127研讨会

20191129 五室第127研讨会 

   目:Impurity Convective Particle Transport Driven by the Impurity Rotation in the Tokamak Plasmas



   间: 2019年11月29 (星期五)  15:30—16:30



The neoclassical impurity convective particle transport in the rotating tokamak plasmas has been investigated analytically. The Coriolis force effect duo to the combined effect the impurity toroidal and poloidal rotation on the poloidal asymmetry of the impurity density is included in the impurity neoclassical transport theory. The radial impurity particle transport purely driven by the impurity toroidal and poloidal rotation is identified explicitly. The new screening effects on the impurity radial transport due to the impurity co-current toroidal rotation and the impurity poloidal rotation in the ion-diamagnetic drift direction are discovered


2019年11月15日 五室第126研讨会

20191115 五室第126研讨会 

  目:1D simulation on impact of density profile on LH wave propagation in fusion edge plasmas



   间: 2019年11月22 (星期五)  9:30—10:30



The investigations on the interaction between electromagnetic (EM) waves and plasma are important in theoretical, experimental and numerical research of fusion plasma. Low hybrid wave (LHW) injection is one of the effective methods to heat the plasma to achieve fusion reaction. Due to the steep density gradient and large fluctuations in tokamak edge region, the more accurate results can be obtained by using the numerical method than the theoretical WKB method. Especially in low frequency range, when the density profile has the large local gradient caused by fluctuation or the gradient scale length is comparable with the wavelength of incident EM waves. In this work, a nonuniform plasma model is used, and the different density gradient profiles with fluctuations are applied to investigate the impact of density profile on LHW propagation in tokamak edge plasma using 1D finite difference time domain (FDTD) simulations. From simulation, the temporary evolution and spatial profiles of plasma variables and EM waves such as the density, velocity, current, electric field, magnetic field, Poynting vector, EM wave power, etc. are obtained. The full-width at half-maximum (FWHM) of radial EM wave power profile is affected by the different incident EM wave frequency, the collision frequency, the plasma density, together with the amplitude and the wave number of fluctuations. Those results will help to understand the LHW propagation in edge plasma.