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Tungsten surfaces are subjected to helium plasma simulating a tokamak divertor environment in the Dynamics of ION Implantation and Sputtering Of Surfaces (DIONISOS) experiment. For this work, surfaces are analyzed in real-time during irradiation with in situ elastic recoil detection to gain dynamic helium concentration depth profiles. The extreme environment of the divertor simulator requires specific...
The paper, after an overview of the typical requirements of Power Supply (PS) systems to control MagnetoHydroDynamic (MHD) instabilities and of technological solutions adopted in some present fusion experiments, reports on the last progress in the production of SiC power devices, which features can be interesting for this type of applications. The advantages of the SiC devices with respect to the...
The Advanced Divertor and RF tokamak eXperiment (ADX) is a compact, high-field device proposed by the MIT Plasma Science and Fusion Center and collaborators [1], which will address critical gaps in world fusion research on the pathway to fusion energy. In addition to developing and testing new divertor concepts at reactor level magnetic field strengths and power densities, ADX will test new antenna...
A preliminary proposal of an ultra-low aspect ratio tokamak based on a unique ECR-assisted plasma central post scheme (toroidal field current carrier) created by an external solenoid is presented. An innovative particle fuelling scheme for the tokamak plasma using the plasma centre post acting as a fuelling particle carrier from near-vertical cryogenic pellet injection is also proposed. This can potentially...
The Advanced Divertor eXperiment (ADX) [1] is a compact, high field (6.5 T with possible upgrade to 8 T), high power density tokamak being proposed to test new advanced divertor concepts at reactor-level conditions. Development and testing of advanced Lower Hybrid Current Drive (LHCD) and Ion Cyclotron Range of Frequency (ICRF) concepts including high-field-side launch capability is also an important...
Magnetic flux surface measurements are the first diagnostic activities at Wendelstein 7-X (W7-X). At present, two out of three flux surface measurement diagnostics are installed. The paper presents the metrology methods used during assembly of the diagnostics, starting with assembly of hosting ports, assembly of diagnostic and the final position measurements. It is shown on the example of two corresponding...
The National Spherical Torus Experiment (NSTX) is currently finishing a multi-year upgrade (NSTX-U) that vastly increased the capabilities of the system. These upgrades required an improved coil protection system to prevent immediate damage as well as fatigue over time to the magnetic coils that control the plasma. Because the action taken by the DCPS affects many other systems, NSTX-U will additionally...
The ITER Steady State Electrical Network (SSEN) is an AC distribution system that provides approximately 120MW of power to supply all of the conventional loads of the ITER facility. The US Domestic Agency is responsible for the procurement and in-kind contribution of 75% of the SSEN equipment, all of which consists of standard commercial grade AC power systems components. This paper reports on lessons...
The International Space Station is among the largest and most complex international cooperative science and technology projects ever undertaken. Completed in 2010, the approximately 500 metric ton, permanently crewed, full-service space platform remains safely operating today as a testament to what great nations can do through peaceful cooperation. At the turn of the 21st century, industrialized nations...
ITER buildings and components have entered deeply into the construction and manufacture phase. Beside the activities on the host place in Cadarache, France, activities for all major components of the ITER enterprise have started around the world.
A prototype of the Toroidal Field (TF) Secondary Quench Detection system (SQD) was developed and implemented with the Korea Superconducting Tokamak Advanced Research (KSTAR) device to carry out the design verification of the SQD. The SQD can detect a quench based on the change of absolute pressures and mass flow rates of helium in the cooling lines of the TF coils. If the primary quench detection...
The National Spherical Torus Experiment (NSTX) is undergoing a significant upgrade. The upgrade increases the toroidal field and pulse length, adds three new diverter coils and a second neutral beam injection (NBI) system. The magnet coil power supply systems for the NSTX have been redesigned with many modifications to reflect NSTX upgrade needs. The NSTX power supply system includes three major parts...
It will be necessary to store and supply hydrogen isotopes needed for Tokamak operation. A storage and delivery system (SDS) is used for storing hydrogen isotopes as a metal hydride form. We designed and fabricated a medium-scale getter bed of depleted uranium (DU). The rapid hydriding of tritium is very important not only for safety reasons but also for the economic design and operation of the SDS...
This paper presents component failure rate data for use in assessment of liquid metal cooling systems. Best estimate data applicable to fusion liquid metal coolants is presented. Repair times for similar components are also referenced in this work. These data support probabilistic safety assessment and reliability, availability, maintainability and inspectability analyses
Under the umbrella of the EUROfusion Consortium and within the Power Plant Physics and Technology (PPPT) Conceptual Design Activities, the project Heating and Current Drive (H&CD) conducts a number of design activities and developments for a next generation clean and environmental friendly, long pulsed (∼2 hours) Demonstration fusion power plant (DEMO). This paper covers the results of the most...
The neutral beam injection (NBI) system for the magnetic confinement experiments ASDEX-Upgrade (AUG) and Wendelstein 7-X (W7-X) require a vacuum system with high pumping speed of up to 3000 m3/s for H2 and large capacity with a gas feed of up to 30 Pa×m3/s and 10 s. It must ensure a vacuum level of a maximum of 10−2 Pa in any section of the neutral beam line in order to avoid re-ionization losses...
The 42GHz Electron Cyclotron resonance Heating (ECRH) system is used in tokamaks Aditya and SST-1 to carry out ECRH related experiments at fundamental and second harmonic. The Gyrotron capable to deliver 500kW power for 500ms duration is commissioned in SST-1 tokamak hall and ∼75m long transmission line is laid to connect both the tokamaks. The corrugated waveguide (ϕ63.5mm) based transmission line...
Neoclassical tearing modes (NTMs) are instabilities that can produce undesirable magnetic islands in tokamak plasmas. They can be stabilized by applying electron cyclotron current drive (ECCD) at the island. The NTM control system on DIII-D can now control multiple modes. Each of 6 mirrors that reflect ECCD beams into the plasma can be assigned to different surfaces in the plasma where NTMs are unstable...
Confined plasma by magnetic field is appear to be abundant and durable source of energy for future aspects. Tokamak is the most advanced device under controlled condition of magnetic field and current flowing in plasma. The interaction of plasma with vacuum vessel gives halo current following poloidal direction with strong outward magnetic force towards vessel. The vertical disruption events caused...
The new Poloidal Field Programmable Power Supply will expand the capabilities of the MST reversed-field pinch experiment. The supply, based on IGBT H-bridges, will generate an arbitrary waveform up to +/− 2700 V at currents up to +/− 85 kA to drive the transformer which produces MST's poloidal field. Additional modules can be added, without other modification, to expand the output current to 115 kA,...
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