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

报告人:潘成康

主持人:叶磊

   间: 2019年11月29 (星期五)  15:30—16:30

   点:4楼会议室

  要:

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

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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

报告人:刘悦教授(大连理工大学)

主持人:夏天阳

   间: 2019年11月22 (星期五)  9:30—10:30

   点:4楼会议室

  要:

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.

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2019年11月15日 五室第125期研讨会

20191115 五室第125期研讨会 

  目:经典粒子场理论在等离子体中的应用

报告人:范培峰

主持人:潘成康

   间: 2019年11月15日(星期五)  14:30—15:30

   点:6楼会议室

  要:

本文分别分相对论性与非相对论性粒子-场系统建立了一般形式的场论, 并推广了弱Euler-Lagrange方程。应用已经建立的一般形式的粒子-场理论分别分析了 Klimontovich-Poisson (KP) 系统, Klimontovich-Darwin (KD) 系 统以及回旋动理学系统的对称性与守恒定律。作为对本文建立的一般理论的验证,我们首先计算了 KP 系统的能量、动量以及角动量守恒定律,所得结果与文献已知结果一致。类似地,对 KD 系统,我们同样分别计算了能量、动量以及角动量守恒定律并发现了 Kaufman 计算的 KD 系统的动量守恒定律选择库伦规范是不合理的。另外,对于回旋动理学系统,此前并未有理论可以计算一般回旋动理学模型的守恒定律。然而,应用本文建立的一般形式的理论模型,我们得到了的任意阶回旋动理学模型的对称性与守恒量的联系。特别地,我们首次计算了二阶回旋动理学的能量守恒定律与动量守恒定律。应用本文建立好的一般形式的相对论性粒子-场理论,我们建立了相对论粒子-电磁场系统的对称性与守恒定律的关系。特别地,我们将Landau得到的相对论性粒子-电磁场系统的能量-动量张量改造成为明显协变式。

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2019年11月11日 五室第124期研讨会

2019年11月11日 五室第124期研讨会 

  目:Integrated modelling in CEA and opportunities for ASIPP

报告人:Dr. GARCIA Jeronimo (CEA France)

主持人:于 治

   间: 2019年11月11日(星期五)  14:30—15:30

   点:601会议室

  要:

Integrated modeling is an essential activity which ensures the right understanding of multiscale (in space and time) magnetically confined plasmas.  The essential physics that such activity must address is heat and particle transport, heat and particle sources, heating  and current drive, plasma equilibrium or current diffusion.A significant effort has been carried out in CEA/IRFM towards this direction since many years ago. For that purpose, the coupling of codes covering multiscale physics into a transport solver  lead to the creation of the CRONOS suite of codes, which has been an international reference in the integrated modeling domain. This activity has been particularly useful for predicting ITER and DEMO future plasmas, analyzing turbulent transport in different tokamaks such as JET or analyzing the synergy between different heating mechanisms. 
   In addition to this activity, and with the aim of speeding-up the calculations while maintaining a similar level of physics detail, several techniques have been applied   such as the creation of neural networks for the quasi-linear code qualikiz (also developed in CEA/IRFM) or the creation or a simplified 0.5 version of CRONOS called METIS.An evolution of CRONOS is now being developed in the framework of an EUROfusion/ITER collaboration: Integrated Modelling Analysis Suite (IMAS) which will heritage not just the main CRONOS features but as well the that of many other different codes worldwide used.
The possibilities for modelling EAST and CFETR will be discussed

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2019年11月7日 五室第123期研讨会

2019117 五室第123期研讨会  

  目:Development of full-f gyrokinetic code GKNET for the study of global transport and profile formation

报告人:Dr. Kenji Imadera(Kyoto University)

主持人:项农

   间: 2019年11月7日(星期四)  14:30—15:00

   点:506办公室内会议室

2019年11月8日 五室第122期研讨会

2019118 五室第122期研讨会 

 目:JET operation and plans for DT campaign

报告人:Dr. GARCIA Jeronimo (CEA France)

主持人:于 治

 间: 2019年11月8日(星期五)  14:30—15:30

 点: 4楼中间会议室

 要:

DT operation is essential to produce efficient energy in magnetically confined plasmas. However, the present knowledge on DT plasmas and its operation is scarce as the more usual DD isotope mix is used in present day tokamaks. This is an issue for the design of future tokamaks such as DEMO or CFETR which mainly rely on DD plasmas experience.

JET will have a DT operation by the end of 2020 with the aim of closing the gap between DD and DT plasmas, minimizing risks for ITER DT operation and to allow better projections to future tokamak reactors. This second DT operation at JET, after the one carried out in 1997, will allow shedding light on some specific differences between DD and TT plasmas such as isotope effects, alpha particle physics, fast ion confinement, impurity production or plasma heating with the help of new diagnostics capabilities with respect to 1997. Towards this objective, previous modelling based on DD extrapolations, has shown that plasma scenarios with high input power and good confinement are expected to generate enough fusion power to observe such phenomena. However, this is a challenge as well from the operational view, as the presence of tritium and the high neutron generation completely changes the way the machine is operated.

Implications for ITER, DEMO and CFETR will be discussed. 

五室第121期研讨会

2019111 五室第121期研讨会 

  目:Simulations of NBI fast ion losses with RMPs in the EAST tokamak

报告人:徐颖峰

主持人:潘成康

时 间: 2019年11月1日(星期五)  10:00—11:00

 点: 4楼中间会议室

 要:

ITER的一个重要问题是要避免I型ELM引起的偏滤器靶板上极大的热脉冲。外部线圈产生的共振磁扰动(RMP)是缓解和抑制ELM的有效方法之一。然而,RMP会破坏快离子的约束从而增强快离子的损失。许多托卡马克装置都开展了RMP影响NBI快离子损失的实验和模拟研究。我们对原先的轨道追踪程序GYCAVA作了许多升级和测试,并将它与NBI程序TGCO和磁流体程序MARS-F集成在一起。我们模拟了EAST上存在n=1 RMP时同向切向NBI产生的高能离子的损失,分析了碰撞、等离子体对RMP的响应以及RMP线圈相位等效应对快离子损失和热负荷的影响。

2019年10月25日 五室第120期研讨会

20191025 五室第120期研讨会 

  目:等离子体鞘层的粒子模拟研究简介

报告人:李德徽

主持人:徐颖峰

   间: 2019年10月25日(星期五)  15:00—16:00

   点: 4楼中间会议室

  要: 

     等离子体-壁相互作用的研究是近十年来等离子体物理中的热点问题之一,该研究对于托卡马克射频天线和偏滤器物理等方面都具有重要意义。对等离子体鞘层的精确模拟,不仅能够为托卡马克边界输运程序提供所需的边界条件,更为实验物理学家提供了靶板表面的粒子流和能流数据,从而为实验提供支持。我们采用粒子模拟程序PPSC对EAST参数下偏滤器靶板表面鞘层进行模拟,尝试建立并维护一个可以复用的鞘层参数数据库,将来更可以接入imas框架,为imas框架下的其他程序提供一个可快速获取的并且较为精确的边界条件。

2019年10月17日 五室第119期研讨会

20191017 五室第119期研讨会

题 目: 简介集成工作流引擎的设计与实现

报告人于治

主持人:李德徽

时  间:2019年10月17日(星期四)  15:00—16:00

地  点:4楼中间会议室

摘  要:

集成建模和模拟过程中,需要在多个计算程序按照复杂的逻辑关系传递数据,并依次执行,这被称为“工作流”。由于历史原因,目前广泛使用的程序所需的计算资源和输入、输出数据格式具有明显的差异,将这些程序整合起来是一个复杂的系统工程。因而,需要引入‘工作流引擎’,通过构建统一的数据和程序调用接口,统筹调度、管理计算程序和计算资源。本研究主要究目标是为满足现代面向集成应用需求,开发高效、灵活、易用的物理理论模拟、实验数据分析环境。本报告将简要介绍目前项目开发进展和下一步规划。

2019年10月11日 五室第118期研讨会

2019年10月11 五室第118期研讨会 

题 目:Numerical study of m/n=3/1 pressure driven mode in the presence of weak magnetic shear

报告人:马骏

主持人:于治

   间: 2019年10月11日(星期五)  15:00—16:00

   点: 6楼中间会议室

  要:

An m/n=3/1 unstable mode can be driven by pressure in the presence of a reversed shear in a cylinder, in which the magnetic shear is small near rational surfaces since qmin = 2.99. The linear mode can be considered as an ideal mode since the resistivity has very little effects upon the mode structure and growth rate for eta <= 10^-7. In nonlinear stage, after long time evolution the mode behaves as a tearing type mode, with final quasi-stationary m/n=3/1 islands. The pressure profile also reaches a new 0/0 state, which is flattened in the vicinity of weak shear region.

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