A5091567523- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Nuclear Physics and Applications
- Solar and Space Plasma Dynamics
- Nuclear and radioactivity studies
- Atomic and Subatomic Physics Research
- Quantum chaos and dynamical systems
- Graphite, nuclear technology, radiation studies
- Dust and Plasma Wave Phenomena
- Gas Dynamics and Kinetic Theory
- Particle Accelerators and Free-Electron Lasers
- Physics of Superconductivity and Magnetism
- Laser-induced spectroscopy and plasma
- Gyrotron and Vacuum Electronics Research
- Planetary Science and Exploration
- Manufacturing Process and Optimization
- Astro and Planetary Science
- Spacecraft and Cryogenic Technologies
- Tunneling and Rock Mechanics
ENN (China)
2021-2024
Shanghai University
2024
State Key Laboratory of Vehicle NVH and Safety Technology
2024
The University of Tokyo
2014-2023
Euclid Network
2021
Institute of Plasma Physics
2010-2020
Chinese Academy of Sciences
2017-2020
University of Science and Technology of China
2017-2018
Max Planck Institute for Plasma Physics
2017
Oak Ridge National Laboratory
2005-2015
The spherical torus is a very small aspect ratio (A < 2) confinement concept obtained by retaining only the indispensable components, such as toroidal field coils, inboard to plasma torus. MHD equilibrium calculations show that plasmas with an edge safety factor qa > 2 are characterized high beta (βt 0.2), low poloidal (βp 0.3), naturally large elongation (κ ≅ 2), current Ip/(aBt0) up about 7 MA·mT−1, strong paramagnetism (Bt/Bt0 1.5), and magnetic helical pitch (Θ comparable F). A...
The National Spherical Torus Experiment (NSTX) is being built at Princeton Plasma Physics Laboratory to test the fusion physics principles for spherical torus concept MA level. NSTX nominal plasma parameters are R0 = 85 cm, a 67 R/a ⩾ 1.26, Bt 3 kG, Ip 1 MA, q95 14, elongation κ ⩽ 2.2, triangularity δ 0.5 and pulse length of up 5 s. heating/current drive tools high harmonic fast wave (6 MW, s), neutral beam injection (5 80 keV, s) coaxial helicity injection. Theoretical calculations predict...
ENN Science and Technology Development Co., Ltd. (ENN) is committed to generating fusion energy in an environmentally friendly cost-effective manner, which requires abundant aneutronic fuel. Proton-boron (p-11B or p-B) considered ideal choice for this purpose. Recent studies have suggested that p-B fusion, although challenging, feasible based on new cross section data, provided a hot ion mode high wall reflection can be achieved reduce electron radiation loss. The beta good confinement of...
Research in NSTX has been conducted to establish spherical torus plasmas be used for high β, auxiliary heated experiments. This device a major radius R0 = 0.86 m and midplane halfwidth of 0.7 m. It operated with toroidal magnetic field B0 ⩽ 0.3 T Ip 1.0 MA. The evolution the plasma equilibrium is analysed between discharges an automated version EFIT code. Limiter, double null lower single diverted configurations have sustained several energy confinement times. stored reached 92 kJ (βt 17.8%)...
Recent experiments (Synakowski et al 2004 Nucl. Fusion 43 1648, Lloyd Plasma Phys. Control. 46 B477) on the Spherical Tokamak (or Torus, ST) (Peng 2000 Plasmas 7 1681) have discovered robust plasma conditions, easing shaping, stability limits, energy confinement, self-driven current and sustainment. This progress has encouraged an update of conditions engineering a Component Test Facility (CTF), (Cheng 1998 Eng. Des. 38 219) which is very valuable step in development practical fusion energy....
Guiding-centre orbits in non-circular axisymmetric tokamak plasmas are studied the constants of motion (COM) space (v, ζ, ψm. Here, v is particle speed, ζ pitch angle with respect to parallel equilibrium current, J||, at point orbit where ψ = ψm, and ψm maximum value poloidal flux function (increasing from magnetic axis) along guiding-centre orbit. Two D-shaped equilibria a flux-conserving having values 1.3% 7.7% used as examples. In this space, each confined corresponds one only point,...
QUEST focuses on the steady state operation of spherical tokamak by controlled PWI and electron Bernstein wave current drive. One main purposes is an achievement long duration discharge with MW-class injected power. As result, should be operated in challenging region heat particle handling. To do handling, high temperature all metal wall up to 623 K closed divertors are planned, which realize steady-state under recycling ratio, R = 1. This a dispensable check DEMO, because pumping avoided as...
T. H. Rider investigated the challenges of sustaining p-11B fusion away from ThermoNuclear Steady-State accounting for Bremsstrahlung losses (TNSSB) in his 1997 paper [Phys. Plasmas 4, 1039 (1997)]. We revisit part work using first-principles particle simulations, which more accurately capture underlying physical processes. This study supports aspects Rider's analysis by considering non-Maxwellian electron velocity distributions and significantly lowering temperatures compared to ion...
Abstract EHL-2 spherical torus (ST) is one of the key steps p- 11 B (proton-boron or hydrogen-boron) fusion energy research in ENN. The produced carried mainly by alpha particles average 3 MeV, which ideally can be converted to electricity with high efficiency (> 80%). However, there exist serious difficulties realize such conversion a device, due density and voltage required. To comprehensively describe progress physics design, this work presents preliminary considerations approaches for...
AbstractThe mission of the National Spherical Torus Experiment (NSTX) is to prove principles spherical torus physics by producing high-βt plasmas that are noninductively sustained and whose current profiles in steady state. The NSTX will be one first ultralow-aspect-ratio tori (R/a ≤ 1.3) operate at high power (Pinput up 11 MW) produce (25 40%), low-collisionality, high-bootstrap-fraction (≤70%) discharges. Both radio-frequency neutral beam heating drive employed. Built into sufficient...
Global magnetohydrodynamic (MHD) stability limits in the National Spherical Torus Experiment (NSTX) have increased significantly recently due to a combination of device and operational improvements. First, more routine H-mode operation with broadened pressure profiles allows access higher normalized β lower internal inductance. Second, correction poloidal field coil induced error-field has largely eliminated locked tearing modes during normal maximum achievable β. As result these...
Broad and important progress in plasma tests, theory, new experiments, future visions of the spherical torus (ST, or very low aspect ratio tokamaks) have recently emerged. These substantially improved our understanding potential properties ST plasmas, since preliminary calculation magnetohydrodynamic equilibria more than a decade ago. Exciting data been obtained from concept exploration level experiments modest capabilities (with major radii up to 35 cm), making scientific contributions...
Pre-ionization experiments have been performed on a tokamak by injecting about 80 kW of microwave power at 35 GHz for up to 15 ms. Microwave absorption occurs the electron cyclotron and upper hybrid resonance frequencies as predicted theory. causes substantial (40%) reductions in loop voltage during initial phase shot. Flux (volt-second) savings with pre-ionization are 30% first 2 ms or 2% total flux expenditure The plasma current begins 200 μs earlier rises 1.4 times more rapidly...
Magnetohydrodynamic (MHD) tokamak equilibria are found with values of β up to 20% and realistic MHD safety factor (e.g. q(axis) = 1 q(edge) 4.8) for tokamaks aspect ratio A 4 D-shaped cross-section. If such can be attained experimentally, they will very attractive decreasing the projected costs power reactors. In flux-conserving (FCT) model, where rapid heating is applied an already relatively hot plasma, these high-β achievable. The quasi-static evolution FCT as increases studied. An...
Large-scale magnetohydrodynamic instabilities of flux-conserving tokamak equilibria are studied computationally. Stable found with up to 5% average $\ensuremath{\beta}$. As $\ensuremath{\beta}$ is increased, the observed take on a strong ballooning character, concentrating near outer edge torus mix poloidal harmonics.
The scenario of toroidal plasma start-up with microwave initiation and heating near the electron cyclotron frequency is suggested examined in this paper. Microwave irradiation from high-field side an anomalously large absorption extraordinary waves upper hybrid resonance are assumed. dominant energy losses assumed to be due magnetic-field curvature parallel drifts, ionization neutrals, cooling by ions, radiation low-Z impurities. It shown particle balance considerations that temperatures...
Coaxial Helicity Injection (CHI) on the National Spherical Torus Experiment (NSTX) has produced 240kA of toroidal current without use central solenoid.Values multiplication ratio (CHI / injector current) up to 10 were obtained, in agreement with predictions.The discharges which lasted for 200ms, limited only by programmed waveform are more than an order magnitude longer duration that any CHI previously a Spheromak or (ST).
Research on the stability of spherical torus plasmas at and above no-wall beta limit is being addressed National Spherical Torus Experiment [M. Ono et al., Nucl. Fusion 40, 557 (2000)], that has produced low aspect ratio plasmas, R/a∼1.27 plasma current exceeding 1.4 MA with high energy confinement (TauE/TauE_ITER89P&gt;2). Toroidal normalized have exceeded 25% 4.3, respectively, in q∼7 plasmas. The observed to increase then saturate increasing li. factor βN/li reached 6, limited by...
An international study conducted by technical experts from Europe, Japan, Russia, and the United States has evaluated issues required testing facilities for development of fusion blanket/first-wall systems found that some key requirements engineering feasibility blanket concepts cannot be established prior to extensive in environment. However, because availability low cost, nonfusion (e.g., fission reactors laboratory experiments) serves a critical role research (R&D) reduces risks costs...
The major objective of the National Spherical Torus Experiment (NSTX) is to understand basic toroidal confinement physics at low aspect ratio and high βT in order advance spherical torus (ST) concept. In do this, NSTX utilizes up 7.5 MW neutral beam injection, 6 harmonic fast waves (HHFWs), it operates with plasma currents 1.5 MA elongations 2.6 a field 0.45 T. New facility, diagnostic modelling capabilities developed over past two years have enabled research team make significant progress...
AbstractThe ARIES research program is a multi-institutional effort to develop several visions of tokamak reactors with enhanced economic, safety, and environmental features. Three are currently planned for the program. The ARIES-I design DT-burning reactor based on "modest" extrapolations from present physics database relies either existing technology or which trends already in place, often programs outside fusion; ARIES-II will employ potential advances physics; ARIES-III conceptual D-3He...
AbstractThe use of a fusion component testing facility to study and establish, during the ITER era, remaining scientific technical knowledge needed by Demo is considered described in this paper. This aims test components an integrated nuclear environment, for first time, discover understand underpinning physical properties, develop improved further testing, time-efficient manner. It requires design with extensive modularization remote handling activated components, flexible hot-cell...