A hybrid discontinuous galerkin method for tokamak edge plasma simulations in global realistic geometry giorgio giorgiani, hugo bufferand, guido ciraolo, philippe ghendrih, frederic schwander, eric serre, patrick tamain to cite this version. For tokamak energy, solid edge is not just a design tool. Pdf divertor target shape optimization in realistic edge. Bootstrap current for the edge pedestal plasma in a. Tokamak edge plasma turbulence interaction with magnetic x. By highlighting potential issues and identifying essential equipment, solid edge enables us to work out exactly it is great to be able to work both on a flat surface or the final profile. A novel flexible fieldaligned coordinate system for tokamak. Magnetic fields and magnetic diagnostics for tokamak plasmas. Theory of edge localized mode suppression by static. To describe both standard and inverse sheath conditions within the framework of. Penalization modeling of a limiter in the tokamak edge plasma.
To address the issue of practicality of the inverse sheath regime for edge tokamak plasma conditions, we perform a set of numerical simulations with 2d edge plasma transport code uedge 4 for a diii. Magnetic geometry and ow shear e ects on tokamak edge. Simulations with the 3d fluid turbulence code tokam3x are performed here to evaluate the impact of a diverted. Plasma density and temperature measured in the diiid tokamak 28. Physicists have been exploring the properties of plasmas within tokamak devices since the 1960s. The local equilibrium of the edge plasma is nonthermal, for which kinetic models are required.
Transport of particles and energy in the edge plasma of the. Particle, momentum and energy conserving fluid transport theory for the tokamak plasma edge weston m. It is notable for its very narrow profile, or aspect ratio. Collisionality and magnetic geometry effects on tokamak edge. Magnetic fields and tokamak plasmas alan wootton 8 for any path l, with n the normal to a two sided surface s. Bootstrap current for the edge pedestal plasma in a diverted. Plasmas, 112502 2006 to study the effects of collisionality and magnetic geometry on electrostatic turbulent transport in the edge and scrapeoff layer of a diverted tokamak plasma by filamentary coherent structures or blobs. Kendl 1 1 institute for ion physics and applied physics, university of innsbruck, association euratom oaw, 6020 innsbruck, austria 2 ief4, forschungszentrum julich, association euratom, 52425 julich, germany email. Linear eigenvalue code for edge plasma in full tokamak xpoint geometry d. Cheng institute of space and plasma sciences, national cheng kung university, tainan 70101, taiwan. The tokamak is one of several types of magnetic confinement devices being developed to produce controlled thermonuclear fusion power.
Gyrokinetic simulation of fast lh bifurcation dynamics in a realistic diverted tokamak edge geometry seunghoe ku1 in collaboration with. Harnessing olcf hpcs for highfidelity simulation of. The model is given by a combination of circles and hyperbolic curves see fig. Stacey georgia institute of technology atlanta, ga 30332 usa june, 2018 abstract a particlemomentumenergy conserving fluxsurfaceaveraged fluid theory for the. P5, boulder, colorado 80301 abstract a tworegion model is proposed to study the effect of collisionality and magnetic. A spherical tokamak is a type of fusion power device based on the tokamak principle.
A tworegion model, coupling the outboard midplane and the xpoint region, was proposed in paper i j. One gram of fusion fuel the hydrogen isotopes deuterium and tritium generates as much power as eight. Magnetic fields and magnetic diagnostics for tokamak. Although simple, it produces a geometry which is suf. Tokamak discharges operating in highcon nement mode hmode 1 exhibit intermittent bursts of heat and particle transport, emanating from the outer regions of the plasma, that are known as typei edge localized modes elms 2. Harnessing olcf hpcs for highfidelity simulation of tokamak. Harnessing olcf hpcs for highfidelity simulation of tokamak edge plasma transport c. In tokamak plasmas, waves and instabilities are elongated along the magnetic.
Choe1 1korea advanced institute of science and technology, department of physics, daejeon 305701, korea. Influence of the inverse sheath on divertor plasma. Magnetic geometry and ow shear e ects on tokamak edge turbulence simulations s. Umansky lawrence livermore national laboratory a new code is presented for solving linear eigenvalue problems from uid models of the edge plasma of tokamaks. Parameters are given by experimental observations, but the computations are otherwise done from first principles. Collisionality and magnetic geometry effects on tokamak edge turbulent transport ii. Turbulence in the edge plasma of a tokamak is a key actor in the determination of the confinement properties. Tokamak edge physics and plasma surface interactions. An important ingredientis a consistent set of boundary conditions as described elsewhere2. The interest in dg methods has increased over the past years. On the other hand, when the aspect ratio is close to unity, the. Linear eigenvalue code for edge plasma in full tokamak x. A hybrid discontinuous galerkin method for tokamak edge.
Pdf gyrofluid turbulence computations in the edge and sol. Due to the very nonlinear coupling between plasma parameters and neutral and impurity sources, 2d codes are necessary to model accurately the effects of divertor geometry on tokamak plasmas. Pppl theory seminar, april 27, 2017 gyrokinetic simulation of. The doughnutshaped torus of the tokamak represented a major breakthrough in plasma science at the time, offering the conditions for temperature levels and plasma confinement times that had never before been reached. The results show that turbulent reynolds stress driven sheared exb flows act in concert with neoclassical orbit loss to. Analysis of classical transport equations for the tokamak. Chang princeton plasma physics laboratory for scidac3 center for edge physics simulation 2014 olcf user meeting, july 22 24, ornl. Gyrokinetic simulation of fast lh bifurcation dynamics in a. A finite element mesh in a tokamak edge geometry request pdf. Edge localized mode elm as well as the formation of. Theory of edge localized mode suppression by static resonant.
Direct numerical simulation has become a useful tool for exploring physics of tokamak edge plasma turbulence because the physics and tokamak geometry are too complex. Numerical modeling of the impact of geometry and wall. Oct 12, 2007 a tworegion model, coupling the outboard midplane and the xpoint region, was proposed in paper i j. High edge pressures can drive large eruptive instabilities that spoil plasma confinement and damage the wall. A fast edge turbulence suppression event has been simulated in the electrostatic version of the gyrokinetic particleincell code xgc1 in a realistic diverted tokamak edge geometry under neutral particle recycling. Fullf gyrokinetic particle simulation of centrally heated. Here we report the first observation of an edge transport barrier formation event in a gyrokinetic simulation carried out in a realistic tokamak edge geometry. Depending on the details of the most promising chosen concept, a dedicated test on specifically upgraded existing facilities or on a dedicated divertor tokamak test dtt facility will be necessary. Through a number of international collaborations, we are deploying advanced diagnostic systems to better understand the physics of the pedestal and edge regions in tokamak plasmas. Gyrofluid turbulence computations in the edge and sol regions. Success with the tokamak has led to the initiation of the international thermonuclear experimental reactor project.
The iter tokamak chamber will be twice as large as any previous tokamak, with a. Guiding center montecarlo codes gcmc in both open and closed field line regions in the tokamak edge geometry are developed for the future applications in examining the integration of core and. A tokamak is a magnificent tribute to albert einsteins emc2. Elms are fairly harmless in presentday tokamaks possessing carbon plasmafacing components. Numerical modeling of the impact of geometry and wall components on transport in the tokamak edge by eric serre, hugo bufferand, a. P5, boulder, colorado 80301 abstract a tworegion model, coupling the outboard midplane and the xpoint region, was. Tokamak edge plasma combines complex magnetic geometry and very rich physics, even in the framework of a linearized fluid model. Giorgio giorgiani, hugo bufferand, guido ciraolo, philippe ghendrih, frederic schwander, et al a. Fusion 49 115021 view the article online for updates and enhancements. We use the two moment gyrofluid model gem3 1 to investigate.
Bootstrap current for the edge pedestal plasma in a diverted tokamak geometry s. A fast lh bifurcation dynamics in a tokamak edge plasma. The results show that two mechanisms of the poloidal flow shearing from radial electric field contribute to the turbulence suppression in sequence. It is designed to produce 1500 mw of fusion power from a deuteriumtritium plasma for pulses of s or longer and to demonstrate the integration of the plasma and nuclear technologies needed for a demonstration reactor. As an attempt to solve all these issues we explore in this work the use of a discontinuous galerkin dg finiteelement method to perform tokamak edge plasma simulations in global realistic geometry. Collisionality and magnetic geometry effects on tokamak edge turbulent transport. A tokamak, like a star, is designed to fuse light atoms into heavier ones. This model clearly resolvessomeimportant issues concerning. Guiding center orbit studies in a tokamak edge geometry. Choe1 1 korea advanced institute of science and technology, department of physics, daejeon 305701, korea 2 princeton plasma physics laboratory, princeton university, princeton, new jersey 08543, usa 3 courant institute of mathematical sciences, new. Transport of particles and energy in the edge plasma of the alcator cmod tokamak by maxim umansky m. Understanding the turbulence in the tokamak edge plasma is challenging to theory and modeling. Highorder discretization of a gyrokinetic vlasov model in. The boundary of tokamak plasmas is characterised by electromagnetic interactions between wavelike and fluidlike motions on space scales down to the ion gyroradius.
Stored energy scales strongly with tokamak major radius, w. Divertor target shape optimization in realistic edge plasma geometry article pdf available in nuclear fusion 547. Myra lodestar research corporation, boulder colorado 80301 m. The basic scales of motion and computational requirements for low frequency fluid drift turbulence are summarized in tutorial fashion, with emphasis on the tokamak edge region. Lin department of physics and astronomy, university of california, irvine, 926974575, usa received 23 may 2007, accepted 17 november 2007 published online 18 march 2008. Toward a firstprinciples integrated simulation of tokamak. Gyrofluid turbulence computations in the edge and sol. The divertor configuration seems to be beneficial for confinement, suggesting an effect on turbulence of the particular magnetic geometry introduced by the xpoint. In a conventional aspect ratio tokamak, the edge bootstrap current from kinetic simulation can be signi. The full twofluid sixfield model has numerous instability branches, which makes it challenging to verify the full model. Guiding center orbit studies in a tokamak edge geometry employing boozer and cartesian coordinates y. Rovisco pais 1, 1049001 lisbon, portugal 2 maxplanckinstitut fur plasmaphysik, euratom association. A traditional tokamak has a toroidal confinement area that gives it an overall shape similar to a donut, complete with a large hole in the middle.
In particular, the model produces the xpoint singularity of the divertor separatrix. For the first time, a special fullf distribution function fullf kinetic transport code suite, consisting of the codes xgc0 and xgc1, has been developed for real tokamak edge geometry. Plasma size and collisionality scaling of iontemperaturegradientdriven turbulence. Gyrokinetic simulation of a fast lh like bifurcation dynamics in a realistic diverted tokamak edge geometry s. Request pdf a finite element mesh in a tokamak edge geometry a new finite element field solver is developed for gyrokinetic particle simulations in the tokamak edge. Simulations of drift resistive ballooning lmode turbulence. Collisionality and magnetic geometry effects on tokamak.
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