Zestaw obrazów 2019
This annual meeting was held at the headquarters of the Helmholtz Society in Berlin March 12–14, 2019. Roughly forty on-site and ten remote participants provided reports on collaborations, grouped into seven topics that reviewed progress during the past year, and planned for the future. The coordinated working group actions (CWGA) serve as a basis to follow up joint actions and were agreed to be followed up in the forthcoming meetings.
Worldwide stellarator research has gained substantial momentum: On Wendelstein 7-X (W7-X, Greifswald, Germany), first campaigns with an uncooled divertor have demonstrated the highest-ever fusion performance normalized to the plasma volume and at the same time, the longest pulse lengths. Deuterium experiments in the Large Helical Device (LHD, Toki, Japan) showed confinement at higher performance than gyro-Bohm scaling—differences in terms of engineering parameters are less clear. Smaller devices are enabling experimental insights for physical understanding, such as turbulence studies in TJ-II (Madrid, Spain), fueling studies in Heliotron-J (Kyoto, Japan), and the examination of flows in HSX (Wisconsin, USA). Progress in the refurbishment of Uragan 2-M (Kharkiv, Ukraine) and new concept devices (CFQS, Chengdu, China) complement the larger experiments, creating new opportunities to assess aspects relevant to reactor-like operation and stellarator optimization.
Equally important, stellarators benefit from the latest cutting-edge developments in diagnostics, heating, and plasma fueling. Coordinated programs in the EU, the US, and Japan link innovative developments [e.g., integrated systems for overload detection (EU consortium), x-ray detectors (Princeton Plasma Physics Laboratory), super-fast surveillance cameras (EU around WIGNER Research Centre for Physics, Hungary) and phase-contrast imaging (MIT)] to the stellarator programs with obvious mutual synergies: the pace of experiments is accelerated by employing these unprecedented measuring capabilities.
More and more benefits for tokamaks are materializing: experience gained in long-pulse stellarator experiments contributes to large-scale devices such as JT-60SA and ITER. A select example is the steady-state fueling pellet injector from Oak Ridge National Laboratory (ORNL) that is being brought to W7-X with additional support from EUROfusion and NIFS, Japan, and which implements technology planned for use on ITER.
The scientific community is excited by early theoretical ideas to explain the latest results from stellarator experiments. Worldwide groups, concentrated in research centers as well as in universities, are increasingly applying their expertise in the understanding of ground-breaking physics questions, such as turbulence in three-dimensional (3D) fields, impurity transport, fast-ion confinement, and plasma flows and currents.
The above-mentioned aspects were the essence of a three-day meeting held at the headquarters of the Helmholtz Society, the funding agency of the German fusion programme (see Fig. 1). The meeting was organized and sponsored by the Max Planck Institute for Plasma Physics. Roughly forty on-site and ten remote participants provided reports on collaborations, grouped into seven topics. In an informal workshop format, the participants discussed proposals for joint action and experiments, taking advantage of comparative studies in different devices. The CWGM is not a scientific conference, but rather a interactive workshop wherein agreements on joint publications under the auspices of the IEA Technology Collaboration Program on Stellarators/Heliotrons are promoted to become the measurable outcome of the CWGM. A session on the program plans of the main contributors served to enable the exchange of information, and the community was invited to provide feedback to programmatic considerations. China’s quickly developing stellarator program, with a sound balance of sustainable build-up of know-how and scientifically interesting new concepts, namely the outline of a quasiaxially symmetric device, attracted great interest.
The sessions were led by colleagues serving as coordinators. The remainder of this report gives brief summaries of each session.
James A. Rome
The evaluation of the EU proposal 871124 - LASERLAB-EUROPE for a new EU contract for Laserlab-Europe, "Laserlab-5" is completed and the EC has just announced the result. The proposal reached the stage of the Grant Agreement preparation. It included also the Laserlab-Europe AISBL Association (www.laserlab-europe.eu) as a new beneficiary. The latter means that all of the organizations that joined this Association will also be involved in the new contract and can take advantage of the EU money.
Laserlab-Europe was a beneficiary also in the CREMLINplus (Connecting Russian and European Measures for Large-scale Research Infrastructures) proposal. That proposal has just been approved as well, and is ready for the Grant preparation stage.
The Joint JRA Meeting and Laserlab Conference on 9-11 October 2019 in Florence (Italy) will include visions and plans for the next four years regarding the upcoming new JRA activities.
Source: Information from Laserlab-Europe coordinators
The new EUROfusion experimental campaign at the Joint European Torus (JET) located at the Culham Centre for Fusion Energy (CCFE), UK started earlier this week. (...)
In the present JET campaign, the experiment M18-05 is allocated a total of six experimental sessions. The first of them was carried out this Wednesday. It was dedicated to demonstrating sawtooth pacing with ICRF power under real time control in good confinement H-mode plasmas. The aim is to provide a tool for reducing central plasma impurity content and improving plasma stability. Overall, the session went very well, achieving a total of 12 plasma discharges with up to 6 MW of ICRF power and 20 MW of NBI.
After the present JET campaign in deuterium (D) fuel, a tritium (T) campaign is planned. These campaigns are made in preparation for the eventual D-T campaign with a fusion reactor relevant 50%-50% D-T fuel mixture. It will be the second D-T campaign at JET; the first D-T campaign at JET was carried out in 1997. The production and physics of born alphas (He-4) at 3.5MeV due to D-T fusion reactions will be tested and assessed with the ITER-like-wall made of beryllium (Be) and tungsten (W). As high-performance discharges are sought, the control of high-Z impurity transport will play a key role during this campaign. (...)
Photo: EUROfusion; CC BY 4.0 licence, www.euro-fusion.org
The US Department of Energy (DOE) has announced the launch of INFUSE, a program created to encourage partnerships in fusion research between industry and DOE national laboratories.
The Innovation Network for Fusion Energy (INFUSE) will select a number of projects for awards between $50,000 and $200,000 each, with a 20 percent project cost share for industry partners. Of particular focus will be "enabling technologies" that could contribute to accelerating the development of fusion energy such as new and improved superconducting magnets, materials science, diagnostics, modelling and simulation, and experimental capabilities.
DOE's Oak Ridge National Laboratory (ORNL) will manage the new program with the Princeton Plasma Physics Laboratory (PPPL). ORNL's Dennis Youchison, a fusion engineer with extensive experience in plasma-facing components, will serve as director, and PPPL's Ahmed Diallo, a physicist with expertise in laser diagnostics, will serve as deputy director.
"I am excited about the potential of INFUSE and believe this step will instill a new vitality to the entire fusion community," says Youchison in the DOE press release. "With growing interest in developing cost-effective sources of fusion energy, INFUSE will help focus current research. Multiple private companies in the United States are pursuing fusion energy systems, and we want to contribute scientific solutions that help make fusion a reality."
The first call for proposals has been issued (deadline 30 June).
Over 100 million degrees.
Experimental Advanced Superconducting Tokamak (EAST), nicknamed Chinese artificial sun, has achieved over 100 million degrees electron temperature in the core plasma in its 2018 four-month-long experiment campaign.
Collaborating with domestic and international colleagues, EAST team in Hefei Institutes of Physical Science, Chinese Academy of Sciences (CASHIPS) made significant progress along the China’s roadmap towards tokamak based fusion energy production.
By effectively integration and synergy of four kinds of heating power, namely, lower hybrid wave heating, electron cyclotron wave heating, ion cyclotron resonance heating and neutral beam ion heating, the plasma current density profile was optimized.
The power injection exceeded 10MW, and plasma stored energy boosted to 300 kJ after scientists optimized the coupling of different heating techniques, and utilized advanced plasma control, theory/simulation prediction. The electron temperature of the core plasma increased beyond 100 million degrees.
Scientists carried out the experiments on plasma equilibrium and instability, confinement and transport, plasma-wall interaction and energetic particle physics to demonstrate the long time scale steady-state H-mode operation with good control of impurity, core/edge MHD stability, heat exhaust using an ITER-like tungsten divertor.
With the ITER-like operation conditions such as radio frequency wave dominant heating, lower torque, water-cooling tungsten divertor, EAST achieved fully non-inductive steady-state scenario with high confinement, high density and high energy confinement enhanced factor.
Meanwhile, to resolve the particle and power exhaust which is of crucial importance for high performance steady state operation, EAST team has employed many techniques in controlling the edge localized modes and tungsten impurity in ITER-like operation conditions, along with active feedback control of divertor heat load.
The operation scenarios of steady-state high performance H-mode and reactor-level electron temperature over 100 million degrees on EAST offer unique contributions toward ITER, Chinese Fusion Engineering Test Reactor (CFETR) and DEMO.
These results provide key data for validation of heat exhaust, transport and current drive models, and enhance confidence in the fusion performance predictions for CFETR.
At present, CFETR physics design focuses on optimization of a third-evolution machine with large radium at 7 m, minor radium 2 m, toroildal magnet field at 6.5-7 Tesla and plasma current 13 MA.
In support of the engineering development of CFETR and a future DEMO, a new National Mega Science Project -- Comprehensive Research Facility will be launched at the end of this year.
This new project will advance the development of tritium blanket test modules, superconducting technology, reactor relevant heating and current drive actuators and sources, and divertor materials.
EAST is the first fully superconducting tokamak with non-circular cross section in the world, designed and constructed by China aiming at key science issues for the application of fusion power. Since its virgin operation in 2006, EAST has become a fully open test facility for world fusion community to conduct steady-state operation and ITER-related physics researches.
Fig. 1 The plasma electron temperature over 100 million degrees achieved in 2018 on EAST. (Image by the EAST Team)
Fig. 2 The extension of EAST operation scenario in 2018, with the comparion of its energy confinement enhanced
factor to the ITER baseline scenario. (Image by the EAST Team)
Contact: ZHOU Shu, Hefei Institutes of Physical Science