A5101692154- Magnetic confinement fusion research
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Atomic and Molecular Physics
- Laser-induced spectroscopy and plasma
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Spectroscopy and Laser Applications
- Glass properties and applications
- Radiation Detection and Scintillator Technologies
- Mesoporous Materials and Catalysis
- Laser Design and Applications
- Semiconductor Lasers and Optical Devices
- Particle Accelerators and Free-Electron Lasers
- Metal and Thin Film Mechanics
- Photonic and Optical Devices
- Astro and Planetary Science
- Pickering emulsions and particle stabilization
Centre for Process Innovation
2024
Imperial College London
2006-2019
University of Dayton
2019
University of Ulster
2019
University of Stirling
2019
Independent Age
2019
Friedrich Schiller University Jena
2019
Brunel University of London
2019
International Civil Aviation Organization
2019
Princeton Plasma Physics Laboratory
2008-2018
Strong magnetohydrodynamic activity has been observed in PDX neutral-beam-heated discharges. It occurs for ${\ensuremath{\beta}}_{T}q>~0.045$ and is associated with a significant loss of fast ions drop neutron emission. As much as 20%-40% the beam heating power may be lost. The instability repetitive bursts oscillations \ensuremath{\le} 1 msec duration at 1-6-msec intervals. dubbed "fishbone instability" from its characteristic signature on Mirnov coils.
Harnessing the exceptional physical properties of graphene often requires its dispersion into aqueous or organic media. Dispersion must be achieved at a concentration and stability appropriate to final application. However, strong interaction between sheets means it disperses poorly in all but few high boiling solvents. This review presents an overview applications discussion strategies: particular effect shear, solvent chemical modification on (including oxide reduced oxide). These...
In order to support the operation of ITER and planned experimental programme an extensive set plasma first wall measurements will be required. The number type required similar those made on present-day large tokamaks while specification measurements—time spatial resolutions, etc—will in some cases more stringent. Many used real time control driving a requirement for very high reliability systems (diagnostics) that provide measurements.
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...
Neutral-beam heating of plasmas in the Tokamak Fusion Test Reactor at low preinjection densities [${n}_{e}$(0)\ensuremath{\simeq}${10}^{19}$ ${\mathrm{m}}^{\mathrm{\ensuremath{-}}3}$] were characterized by ${T}_{e}$(0)=6.5 keV, ${T}_{i}$(0)=20 ${n}_{e}$(0)=7\ifmmode\times\else\texttimes\fi{}${10}^{19}$ ${\mathrm{m}}^{\mathrm{\ensuremath{-}}3}$, ${\ensuremath{\tau}}_{E}$=170 msec, ${\ensuremath{\beta}}_{\mathrm{theta}}$=2, and a d(d,n${)}^{3}$He neutron emission rate ${10}^{16}$...
The discrete Fourier transform of a sequence, which can be computed using the fast algorithm, represents samples z equally spaced around unit circle. In this letter, technique is discussed and illustrated for transforming sequence to new whose equal original at unequally angles
Neutral-beam--heated plasmas in TFTR show evidence of substantial non-Ohmically driven toroidal current, even for balanced beam momentum input. The observations are inconsistent with calculations including only Ohmic and beam-driven currents, presently can be matched by models the neoclassical bootstrap current.
A technique is presented which enables the recovery of probability distribution for single scattering from plural-scattering electron energy loss data. Neither parameter t/λ nor details component processes need be known. The computational method uses Fourier series in order to overcome a number practical problems application convolution methods, include instrumental effects and permit processing data with large values parameter. noise, specimen oxidation accuracy are considered.
Wall conditioning in the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] by injection of lithium pellets into plasma has resulted large improvements deuterium–tritium fusion power production (up to 10.7 MW), Lawson triple product 1021 m−3 s keV), and energy confinement time 330 ms). The maximum current for access high-performance supershots been increased from 1.9 2.7 MA, leading stable operation at stored values greater than 5 MJ. amount on limiter...
A Thomson scattering system is being developed for Joint European Torus with 15 mm spatial resolution and a foreseen accuracy temperature better than 15% at density of 1019 m−3. This required the internal transport barrier edge pedestal it can not be fully achieved present light detection ranging systems. The laser this Nd:YAG, 5 Joule, 20 Hz. Scattering volumes from R=2.9 m to R=3.9 are imaged onto 1 diameter fibers, F/25 collection aperture. Two fibers used per volume. Using optical delay...
A transport code (TRANSP) is used to simulate future deuterium-tritium (DT) experiments in TFTR.The simulations are derived from 14 TFTR DD discharges, and the modelling of one supershot discussed detail indicate degree accuracy TRANSP modelling.Fusion energy yields 01 particle parameters calculated, including profiles slowing down time, average energy, AlfvBn speed frequency.Two types simulation discussed.The main emphasis on DT equivalent, where an equal mix D T substituted for initial...
Peak fusion power production of 6.2\ifmmode\pm\else\textpm\fi{}0.4 MW has been achieved in TFTR plasmas heated by deuterium and tritium neutral beams at a total 29.5 MW. These have an inferred central alpha particle density 1.2\ifmmode\times\else\texttimes\fi{}${10}^{17}$ ${\mathrm{m}}^{\mathrm{\ensuremath{-}}3}$ without the appearance either disruptive magnetohydrodynamics events or detectable changes Alfv\'en wave activity. The measured loss rate energetic particles agreed with...
General plasma physics principles state that power flow Q(r) through a magnetic surface in tokamak should scale as Q(r)= {32π2Rr3Te2c nea/[eB (a2−r2)2]} F(ρ*,β,ν*,r/a,q,s,r/R,...) where the arguments of F are local, nondimensional parameters and gradients. This paper reports an experimental determination how varies with normalized gyroradius ρ*≡(2TeMi)1/2c/eBa collisionality ν*≡(R/r)3/2qRνe(me/ 2Te)1/2 for discharges prepared so other remain close to constant. Tokamak Fusion Test Reactor...
Using a time domain method the Kramers-Kronig integrals are derived without recourse to complex analysis (except in evaluating Fourier transform of sgn (t)). From result, series for numerical evaluation causality relations is derived. This eliminates need use integration, logarithms function and consideration Cauchy principal parts. Through fast algorithm calculation can be vary rapid. The accuracy technique considered.
The gel process for making silica was studied by infrared spectrophotometry of solid samples in various stages dehydration. Spectra were recorded the high‐frequency overtone region (2500 to 8000 cm ‐1 ) as well fundamental absorption (200 4000 ), depending on nature sample. Molecular water distinguished from silanol groups and effects hydrogen bonding observed. Drying heat treatment gels at low temperatures (<150°C) causes a loss unbonded included water, but significant hydrogen‐bonded...
Aqueous precipitation has been used to prepare spherical ZnO particles. These powders have shown be suitable for use in the preparation of varistors. The uniform size distribution and coating these with appropriate dopants allowed fabrication varistors improved properties over those fabricated from conventionally ball‐milled calcined powders. were a high coefficient nonlinearity (∼44) nonohmic region, sharp change electrical behavior ohmic nonohmic, resistivity (5×10 12 SOM°m) at low voltages.
Emulsion templating has been used to prepare highly porous polyHIPE materials by thiol–ene photoinitiated network formation. Commercially available multifunctional thiols and acrylates were formulated into water-in-oil high internal phase emulsions (HIPEs) using an appropriate surfactant, the HIPEs photo-cured. The temperature of HIPE aqueous was found influence morphology resulting materials. In agreement with previous work, a higher (80 °C) gave rise larger mean void interconnect diameter....
Micro-stereolithography (μSL) is used to produce 3D porous polymer structures by templating high internal phase emulsions. A variety of are produced, including lines, squares, grids, and tubes. The porosity matches that materials produced conventional photopolymerization.
We describe the preparation of porous polymeric scaffolds via polymerization oil phase in high internal water-in-oil-emulsions using amphiphilic block copolymers polystyrene-b-poly(ethylene oxide), polystyrene-b-poly(acrylic acid), poly(1,4-butadiene)-b-poly(ethylene and poly(1,4-butadiene)-b-poly(acrylic acid) as surfactants. show that anchor to polymerized lipophilic block, which can occur by chemical and/or physical entanglement consequent presentation hydrophilic on pore surfaces. The...
The National Spherical Torus Experiment (NSTX) multipoint Thomson scattering system has been in operation for nearly two years and provides routine Te(R,t) ne(R,t) measurements. laser beams from 30 Hz Nd:YAG lasers are imaged by a spherical mirror onto 36 fiber-optic bundles. In the present configuration, output ends of 20 these bundles instrumented with filter polychromators avalanche photodiode detectors. this article, we discuss implementation installed collection optics. We follow...
Turbulent filaments in visible light emission corresponding mainly to density fluctuations at the edge have been observed large aspect ratio tokamaks: TFTR, ASDEX, Alcator C-Mod, and DIII-D. This article reports on similar turbulent structures National Spherical Torus Experiment (NSTX) using a fast-framing, intensified, digital camera. These were previously detected high recycling regions, such as limiters or antennas, where line from neutral atoms was modulated by local plasma density....
A new method of actively modifying the plasma-wall interaction was tested on Tokamak Fusion Test Reactor. laser used to introduce a directed lithium aerosol into discharge scrape-off layer. The introduced in this fashion ablated and migrated preferentially limiter contact points. This allowed be influenced situ real time by external means. Significant improvement energy confinement fusion neutron production rate as well reduction plasma Zeff have been documented neutral beam heated plasma....
Research Article| September 01, 1991 Incremental heating of hornblende in vacuo: Implications for 40Ar/39Ar geochronology and the interpretation thermal histories J.K.W. Lee; Lee 1Department Geological Geophysical Sciences, Princeton University, Princeton, New Jersey 08544 Search other works by this author on: GSW Google Scholar T. C. Onstott; Onstott K. V. Cashman; Cashman R. J. Cumbest; Cumbest D. Johnson Author Article Information Publisher: Society America First Online: 02 Jun 2017...
After many years of fusion research, the conditions needed for a D–T reactor have been approached on Tokamak Fusion Test Reactor (TFTR) [Fusion Technol. 21, 1324 (1992)]. For first time unique phenomena present in plasma are now being studied laboratory plasma. The magnetic experiments to study plasmas using nearly equal concentrations deuterium and tritium carried out TFTR. At maximum power 10.7 MW, 39.5 MW neutral-beam heating, supershot discharge 6.7 high-βp following current rampdown....