11 research outputs found
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ICF research at Los Alamos
It is apparent that short wavelength lasers (<500 nm) provide efficient coupling of laser energy into ICF target compression. KrF lasers (248 nm) operate at near-optimum wavelength and provide other potential benefits to ICF target coupling (e.g., bandwidth) and applications (high wallplug efficiency and relatively low cost). However, no driver technology has yet been shown to meet all of the requirements for a high-gain ICF capability at a currently acceptable cost, and there are still significant uncertainties in the driver-target coupling and capsule hydrodynamics that must be addressed. The Los Alamos research program is designed to assess the potential of KrF lasers for ICF and to determine the feasibility of achieving high gain in the laboratory with a KrF laser driver. Major efforts in KrF laser development and technology, target fabrication and materials development, and laser-matter interaction and hydrodynamics research are discussed. 27 refs., 10 figs
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Carbon dioxide laser development and asymmetry in laser driven implosions
PROMOTING EFFECTIVE SCIENCE TEACHER EDUCATION AND SCIENCE TEACHING: A FRAMEWORK FOR TEACHER DECISION-MAKING
Towards Bioinformatics Resourceomes
In science fiction, human beings have been depicted able to colonize planets of far stars exploiting their chemical and mining resources. We can image bioinformatics as a very dynamic universe, continuously growing under our eyes. More and more scientists are approaching it and would like to easier explore it, discovering the resources that can be found in every space region (i.e. related to every bioinformatics topic). We propose to intuitively organize into Resourceomes the hierarchical vision of a scientific domain perceived by its scientists, connecting the related resources to the topics they concern. A Resourceome can be seen as a map of a scientific "universe". A semantic browser for Resourceomes permits to intuitively navigate in the domain, eventually zooming it in and out. Once discovered a resource of interest it is possible to be "tele-ported" to it. More importantly, the maps are "machine understandable", being built on ontologies and published on the Web with Semantic Web technologies
Overview of physics results from MAST
Major developments on the Mega Amp Spherical Tokamak (MAST) have enabled important advances in support of ITER and the physics basis of a spherical tokamak (ST) based component test facility (CTF), as well as providing new insight into underlying tokamak physics. For example, L-H transition studies benefit from high spatial and temporal resolution measurements of pedestal profile evolution (temperature, density and radial electric field) and in support of pedestal stability studies the edge current density profile has been inferred from motional Stark effect measurements. The influence of the q-profile and E x B flow shear on transport has been studied in MAST and equilibrium flow shear has been included in gyro-kinetic codes, improving comparisons with the experimental data. H-modes exhibit a weaker q and stronger collisionality dependence of heat diffusivity than implied by IPB98(gamma, 2) scaling, which may have important implications for the design of an ST-based CTF. ELM mitigation, an important issue for ITER, has been demonstrated by applying resonant magnetic perturbations (RMPs) using both internal and external coils, but full stabilization of type-I ELMs has not been observed. Modelling shows the importance of including the plasma response to the RMP fields. MAST plasmas with q > 1 and weak central magnetic shear regularly exhibit a long-lived saturated ideal internal mode. Measured plasma braking in the presence of this mode compares well with neo-classical toroidal viscosity theory. In support of basic physics understanding, high resolution Thomson scattering measurements are providing new insight into sawtooth crash dynamics and neo-classical tearing mode critical island widths. Retarding field analyser measurements show elevated ion temperatures in the scrape-off layer of L-mode plasmas and, in the presence of type-I ELMs, ions with energy greater than 500 eV are detected 20 cm outside the separatrix. Disruption mitigation by massive gas injection has reduced divertor heat loads by up to 70%