A5015369073- Magnetic confinement fusion research
- Fusion materials and technologies
- Laser-induced spectroscopy and plasma
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- X-ray Spectroscopy and Fluorescence Analysis
- High voltage insulation and dielectric phenomena
- Atomic and Molecular Physics
- Electron and X-Ray Spectroscopy Techniques
- Metal and Thin Film Mechanics
- Impact of Light on Environment and Health
- Cold Fusion and Nuclear Reactions
- Radiation Detection and Scintillator Technologies
- Analytical chemistry methods development
- Semiconductor materials and devices
- Ionosphere and magnetosphere dynamics
- Spectroscopy Techniques in Biomedical and Chemical Research
- Mass Spectrometry Techniques and Applications
- Photocathodes and Microchannel Plates
- Mercury impact and mitigation studies
- Nuclear Physics and Applications
- Luminescence Properties of Advanced Materials
- Nuclear reactor physics and engineering
- Thermography and Photoacoustic Techniques
University of Massachusetts Lowell
2023-2024
OSRAM (United States)
1998-2011
Princeton Plasma Physics Laboratory
1993-1995
Princeton University
1993-1995
Joint European Torus
1994
Advanced Science Research Center
1994
Los Alamos National Laboratory
1994
Faculty of 1000 (United Kingdom)
1994
Canadian Fuels Association
1994
Columbia University
1994
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...
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....
The Tomamak Fusion Test reactor has performed initial high-power experiments with the plasma fueled nominally equal densities of deuterium and tritium. Compared to pure plasmas, energy stored in electron ions increased by \ensuremath{\sim}20%. These increases indicate improvements confinement associated use tritium possibly heating electrons \ensuremath{\alpha} particles created D-T fusion reactions.
The confinement and heating of supershot plasmas are significantly enhanced with tritium beam injection relative to deuterium in the Tokamak Fusion Test Reactor [Plasma Phys. Controlled 26, 11 (1984)]. global energy local thermal transport analyzed for fueled quantify their dependence on average mass hydrogenic ions. Radial profiles densities determined from D–T fusion neutron emission profile. inferred scalings isotopic quite strong, τE∝〈A〉0.85±0.20, τEthermal∝〈A〉0.89±0.20,...
The $t\left(d,n\right)\ensuremath{\alpha}$ and $d(d,n{)}^{3}\mathrm{He}$ neutron emissivity profiles are measured in a deuterium neutral-beam--heated plasma where small amount of tritium (T) gas has been puffed. density is inferred from the emissivities, transport coefficients ( $D,V$) determined. particle diffusivities T ${}^{4}$He thermal diffusivity similar magnitude profile shape. convective velocity for $r/a<0.6$, anomalous $r/a>0.6$. These first measurements $D$ $V$ hydrogen isotope...
Both global and thermal energy confinement improve in high-temperature supershot plasmas the Tokamak Fusion Test Reactor (TFTR) when deuterium beam heating is partially or wholly replaced by tritium heating. For same power, tritium-rich obtain up to 22% higher total energy, 30% ion 20-25% central temperature. Kinetic analysis of temperature density profiles indicates a favorable isotopic scaling heat transport electron particle transport, with τEi(a/2) ∝ ⟨A⟩0.7-0.8 τpe(a) ⟨A⟩0.8.
The first spectroscopic measurements of tritium Balmer α(Tα) emission from a fusion plasma were made on TFTR using Fabry-Perot interferometer. line is partially blended with the deuterium α(Dα) line, commonly used in edge diagnostics, and contributions Hα, Dα Tα are separated by spectral analysis. data measure fuelling accumulated limiter, as well amount neutral generated charge exchange ions. became detectable high power, only, beam injection discharge at level Tα/(Hα + Tα) = 2%....
Three campaigns, prior to July 1994, attempted increase the fusion power in DT plasmas on Tokamak Fusion Test Reactor (TFTR). The first campaign was dedicated obtaining >5 MW of while avoiding MHD events similar JET X-event. second aimed at producing maximum irrespective proximity limits, and achieved 9 limited by a disruption. third increased energy confinement time using lithium pellet conditioning raising ratio alpha heating beam heating.
X-ray induced fluorescence is used to measure the elemental densities of minority additives in a metal-halide arc contained inside translucent ceramic envelope. A monochromatic x-ray beam from Sector 1 Insertion Device beamline at Advanced Photon Source excite K-shell constituents lamp dosed with DyI3 and CsI. Fluorescence scattered photons are collected by cryogenic energy-resolving Ge detector. The high signal-to-noise spectra show strong Dy, Cs, I, as well elastic scattering Hg. Radial...
The use of x-ray induced fluorescence to measure elemental densities in a metal–halide lighting arc is described. High-energy synchrotron radiation generated on the Sector 1 Insertion Device beam line at Advanced Photon Source induces K-shell high-pressure plasma arc. detected spectrally resolved, so that multiple species are observed simultaneously. Absolute calibration measured straightforward and robust. penetrating nature high-energy photons allows these measurements be made situ, with...
Fiber-based diagnostic systems suffer from induced luminescence and transmission losses due to neutron γ radiation high-power D-D D-T discharges. Whereas the follows rate, loss increases monotonically during a shot decays slowly after discharge. To study these effects we are using dedicated fiber coils (increasing exposed length) which positioned close discharge vessel flux) detectors. The fibers studied typical for diagnostics on TFTR. One is of same type used JET/TFTR heated study. We...
Spectroscopic measurements of tritium Balmer-alpha (Tα) emission from a fusion plasma are presented. A Fabry–Perot interferometer is used to measure the Hα, Dα, Tα spectrum in current D–T experimental campaign on TFTR and contributions H, D, T separated by spectral analysis. The line was measurable at concentrations /(Hα+Dα+Tα) down 2%.
The diagnostic technique of x-ray absorption imaging Hg vapour in high-intensity discharge lamps has been extended. X-ray used previously to determine the time-averaged absolute density (Curry J J, Sakai M and Lawler E 1998 J. Appl. Phys. 84 3066). Now, using an intensified charge-coupled device detector synchrotron radiation, time-resolved measurements have made. Although no significant time-dependence was seen as a function electrical phase for electronically ballasted lamp, real-time...
Research on the correlation between metal levels in blood and Covid-19 infection has been conducted primarily by assessing how each individual is linked to different aspects of disease using samples from donors with various severity infection. Using logistics regression LIBS spectra plasma collected pre- post- pandemic known have developed antibodies SARS-Cov-2 virus, we show that relying Na, K, Mg together more efficient at differentiating two types than any single alone.
A JET/TFTR study to investigate attenuation and luminescence effects due neutron irradiation of optical fibers that have been heated 400 °C is described. significant improvement in fiber behavior temperature annealing expected which may be relevant fiber-related, tokamak diagnostics exposed high flux. Results show an unheated shows ≳20% transmission loss while identical, only ∼1%. Experimental details are presented.
De-mixing of additives in a vertically-operated, ceramic DyI3–CsI–Hg metal-halide arc lamp has been observed by examining the ratios absolute elemental densities as function position. As have obtained directly x-ray induced fluorescence (Curry J J, Adler H G, Shastri S D and Lee W-K 2003 J. Appl. Phys. 93 2359), this approach reveals extent mixing (or de-mixing) with no intervening assumptions about equilibrium, local temperature, or accuracy partition functions. The metal studied show...
The final hardware modifications for tritium operation have been completed the Tokamak Fusion Test Reactor (TFTR) [Fusion Technol. 21, 1324 (1992)]. These activities include preparation of gas handling system, installation additional neutron shielding, conversion toroidal field coil cooling system from water to a FluorinertTM modification vacuum handle tritium, preparation, and testing neutral beam deuterium–deuterium (D–D) run simulate expected deuterium–tritium (D–T) operation. Testing...
Intense fluxes of 14-MeV neutrons from deuterium–tritium (DT) fusion reaction in TFTR resulted significantly enhanced background noise levels and reduced quality data the shielded UV (SPRED) visible (VIPS) grating spectrometers x-ray imaging system (XIS) camera. Both levels, attributed to gamma rays small angle neutron scattering, large spikes, nuclear reactions silicon detectors, were observed. frequency spikes higher, on a per basis, spike amplitudes higher for DT than DD operation. The...
Electrodes in a high intensity discharge (HID) lamp play major role the successful operation of these light sources. On one hand "good" electrode has to fulfil fundamental task supplying power discharge, on other it survive demanding conditions thermal and chemical environment an HID for many hours operation. The performance electrodes during starting continuous is strongly dependent type ballast used. Improper design ballasts can lead life-limiting problems. paper focuses diagnostic efforts...
We applied high-resolution coherent anti-Stokes Raman spectroscopy (CARS) to measure the gas temperature at a number of points within nitrogen-filled outer jacket 360 W metal halide lamp. A comparison between measured rotationally resolved N 2 CARS spectra with spectral simulations collected 500 and 1000 K allowed each point in lamp be determined. In addition demonstrating diagnostic power technique high-intensity discharge lamp, temperatures calculated axial radial profiles was achieved....