A5071241374- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Nuclear Materials and Properties
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Nuclear and radioactivity studies
- Laser-Plasma Interactions and Diagnostics
- Nuclear Physics and Applications
- Gyrotron and Vacuum Electronics Research
- Solar and Space Plasma Dynamics
- Laser-induced spectroscopy and plasma
- Superconducting Materials and Applications
- Graphite, nuclear technology, radiation studies
- Electrostatic Discharge in Electronics
- High-Temperature Coating Behaviors
- Adrenal Hormones and Disorders
- Bat Biology and Ecology Studies
- Electromagnetic Launch and Propulsion Technology
- Vacuum and Plasma Arcs
- Ion-surface interactions and analysis
- Sport Psychology and Performance
- Microwave and Dielectric Measurement Techniques
- Electromagnetic Compatibility and Measurements
Oak Ridge National Laboratory
2003-2019
National Technical Information Service
2011-2018
Office of Scientific and Technical Information
2011-2018
University of Tennessee at Knoxville
1995-2011
University of California, Berkeley
2011
University of Nevada, Las Vegas
2011
Logos Technologies (United States)
2011
Deleted Institution
2008
Royal Canadian Navy
2008
Plasma Technology (United States)
2001
Access to the MHD second stability regime has been achieved in ATF torsatron. Experimental \ensuremath{\beta} values (${\ensuremath{\beta}}_{0}$\ensuremath{\le}3%, with fast ions contributing \ensuremath{\approxeq}(1/3 of pressure at high \ensuremath{\beta}) are well above theoretical transition value (${\ensuremath{\beta}}_{c}$\ensuremath{\approxeq}1.3% for ideal modes) required reach this regime. The relatively low ${\ensuremath{\beta}}_{c}$ results from operation peaked profiles. measured...
The toroidal current observed during electron cyclotron heating in the Advanced Toroidal Facility torsatron is identified as bootstrap current. currents, ranging between +4 and -2 kA, agree well with predictions of neoclassical theory magnitude parametric dependence, determined by systematic scans quadrupole (shaping) dipole (magnetic axis shift) moments poloidal magnetic field. It has been shown that a stellarator can be externally controlled, zero-current operation achieved.
Abstract: Introduction: The mental health of elite athletes has been recognised as great importance. There have relatively few studies examining the prevalence problems in swimmers. None commented on range psychosocial associated with ill-health. aim this study was to identify common and Methods: conducted a national swimming squad competing at international level. All (n=55) were invited participate. response rate 63.3% (n=36). cross-sectional design. Data collected using battery...
Doppler-free saturation spectroscopy provides a very powerful method to obtain detailed information about the electronic structure of atom through measurement spectral line profile. This is achieved significant decrease in Doppler broadening and essentially an elimination instrument inherent passive spectroscopic techniques. In this paper we present technique associated physics addition how one selects appropriate transition. Simulations Hδ spectra are presented illustrate increased...
A fourfold increase in the conversion of thermal electron Bernstein waves (EBW) to extraordinary mode (X mode) was measured when density scale length (Ln) progressively shortened by a local boron nitride limiter scrape-off an Ohmically heated National Spherical Torus Experiment plasma [M. Ono, S. Kaye, M. Peng et al., Proceedings 17th IAEA Fusion Energy Conference (IAEA, Vienna, 1999), Vol. 3, p. 1135]. The maximum efficiency approached 50% Ln reduced 0.7 cm, agreement with theoretical...
The Advanced Toroidal Facility (ATF) torsatron was designed on a physics basis for access to the second stability regime and an engineering independent fabrication of high-accuracy components. actual construction, assembly, initial operation ATF are compared with characteristics expected during design phase.
Fast wave heating experiments in the ion cyclotron range of frequencies (ICRF) were performed on target plasmas produced by 350 kW electron at 53 GHz and also neutral beam injection Advanced Toroidal Facility (ATF). Various regimes investigated frequency between 9.2 MHz 28.8 with magnetic fields 0.95 T 1.9 axis. The nominal pulse lengths up to 200 RF power 100 400 ms. Data from spectroscopy, loading measurements, edge Langmuir probes used characterize induced effects ATF plasma. In hydrogen...
Recent experiments in the Advanced Toroidal Facility (ATF) torsatron [Plasma Physics and Controlled Nuclear Fusion Research 1990 (IAEA, Vienna, press)] have emphasized role of magnetic configuration control transport studies. Long-pulse plasma operation up to 20 sec has been achieved with electron cyclotron heating (ECH). With neutral beam injection (NBI) power ≥1 MW, global energy confinement times 30 msec obtained line-average densities 1.3×1020 m−3. The operational space ATF are roughly...
Abstract A survey of the degree mental impairment, physical disability and behavioural problems was undertaken in residents psychogeriatric continuing care beds at Friern Hospital (n=96) Islington Local Authority old people's homes (OPHs) (n = 104). High levels dependency were identified, particularly those subjects with a clinical diagnosis dementia, who constituted 80% hospital sample 43% OPHs. Precipitants admission differed between OPH groups (incontinence, aggression wandering vs poor...
Access to the magnetohydrodynamic (MHD) second stability regime has been achieved in Advanced Toroidal Facility (ATF) torsatron [Fusion Technol. 10, 179 (1986)]. Operation with a field error that reduced plasma radius and edge rotational transform resulted peaked pressure profiles increased Shafranov shift lowered theoretical transition ideal MHD β0≊1.3%; experimental β values (β0≤3%) are well above this transition. The measured magnetic fluctuations decrease increasing β, profile broadens,...
Laser-induced breakdown spectroscopy (LIBS) was undertaken using an instrument which used a high-powered microscope to deliver the light and tightly focused low energy laser beam onto surface of solid sample. A micro-plasma generated on sample under test even though amount energy/pulse from 532 nm <1 mJ. Rare earth elements such as europium, gadolinium, lanthanum, neodymium, praseodymium, samarium, transition metal, yttrium, were tested. These are important in nuclear fission reactions...
Measurements of third harmonic electron cyclotron emission have been made on the Advanced Toroidal Facility (ATF). Electron temperatures extracted from harmonic, optically thin, (ECE) measurements. The radial and temporal evolutions temperature characterized for resonance heated discharges early stages neutral beam plasmas. A slab based model incorporating equation radiation transfer ray tracing has used to calculate expected ECE. results compared with experimental polarization ECE during 1...
The characteristics of plasmas in the Advanced Toroidal Facility (ATF) have proven to be strongly dependent on type wall conditioning employed. A succession techniques, beginning with glow discharge cleaning and baking, evolving gettering chromium titanium, led progressive improvement plasma parameters. Gettering titanium has reduced low-Z impurity content by a factor 3, lowered radiated power 2.5–3.5, improved control over electron density. maximum values achieved for stored energy, line...
Density fluctuations in low-collisionality, low-beta (β∼0.1%), currentless plasmas produced with electron cyclotron heating (ECH) the Advanced Toroidal Facility (ATF) torsatron [Fusion Technol. 10, 179 (1986)] have been studied using a 2 mm microwave scattering diagnostic. Pulsed gas puffing is used to produce transient steepening of density profile from its typically flat shape; this leads growth when temperature and gradients both point same direction confinement region. The wave number...
The Advanced Toroidal Facility (ATF) torsatron [Fusion Technol. 10, 179 (1986)] has completed experiments focusing on microwave scattering measurements of density fluctuations and transport studies utilizing the modulation dimensionless parameters. Microwave electron in core low-collisionality cyclotron heated (ECH) plasmas show features that might be evidence trapped instabilities. Starting from gyro-Bohm scaling, additional dependence confinement parameters ν* β (collisionality beta) been...
STUDY OBJECTIVE--The aim was to assess the relationship between social deprivation, as measured by Jarman under-privileged area score (UPA score), and psychiatric admission rates length of stay within an inner London borough. DESIGN--The study a retrospective survey for electoral wards in borough Islington relation UPA scores subscores. SETTING--Islington Health Authority at Whittington Friern Hospitals. PATIENTS--All admissions during year 1985 were studied (n = 778). MAIN RESULTS--No...
Recent experiments in the Advanced Toroidal Facility (ATF) [Fusion Technol. 10, 179 (1986)] have been directed toward investigations of basic physics mechanisms that control confinement this device. Measurements density fluctuations throughout plasma volume provided indications for existence theoretically predicted dissipative trapped electron and resistive interchange instabilities. These identifications are supported by results dynamic configuration scans magnetic fields during which well...
Experiments involving plasma improvement, confinement scaling, bootstrap currents, and edge fluctuations have been carried out in the Advanced Toroidal Facility (ATF) torsatron [Fusion Technol. 10, 179 (1986)]. Average densities n̄e≤9×1019 m−3 obtained, with global energy times τ*E≤20 msec. Confinement generally follow stellarator/torsatron empirical scaling law, τSL =0.17×P−0.58n0.69eB0.84a2R0.75 (with seconds, power P megawatts, density ne 1020 m−3, radius a major R meters). Gas injection...