Findings of the US Research Needs Workshop on the Topic of Fusion Power (open access)

Findings of the US Research Needs Workshop on the Topic of Fusion Power

The US Department of Energy, Office of Fusion Energy Sciences (OFES) conducted a Research Needs Workshop, referred to as ReNeW, in June 2009. The information developed at this workshop will help OFES develop a plan for US fusion research during the ITER era, roughly the next two decades. The workshop was organized in five Themes, one of which was Harnessing Fusion Power (or Fusion Power for short). The top level goal of the Fusion Power Theme was to identify the research needed to develop the knowledge to design and build, with high confidence, robust and reliable systems that can convert fusion products to useful forms of energy in a reactor environment, including a self-sufficient supply of tritium fuel. Each Theme was subsequently subdivided into Panels to address specific topics. The Fusion Power Panel topics were: fusion fuel cycle; power extraction; materials science; safety and environment; and reliability, availability, maintainability and inspectability (RAMI). Here we present the key findings of the Fusion Power Theme.
Date: September 16, 2009
Creator: Meier, W. R.; Raffray, A. R.; Kurtz, R. J.; Morley, N. B.; Reiersen, W. T.; Sharpe, P. et al.
Object Type: Article
System: The UNT Digital Library

National Set of Hydrogen Codes and Standards for the US

The US has a national set of codes and standards that address the use of hydrogen technologies. These documents are published by several organizations and are not all directly adopted by government authorities. The US Department of Energy (DOE) has acted as the central organizing group to identify these documents and present them as a coherent and integrated set of requirements.
Date: September 16, 2009
Creator: Rivkin, C. H.
Object Type: Presentation
System: The UNT Digital Library
Ultra-high Resolution Optics for EUV and Soft X-ray Inelastic Scattering (open access)

Ultra-high Resolution Optics for EUV and Soft X-ray Inelastic Scattering

We describe a revolutionary new approach to high spectral resolution soft x-ray optics. Conventionally in the soft x-ray energy range, high spectral resolution is obtained by use of a relatively low line density grating operated in 1st order with small slits. This severely limits throughput. This limitation can be removed by use of a grating either in very high order, or with very high line density, if one can maintain high diffraction efficiency. We have developed a new technology for achieving both of these goals which should allow high throughput spectroscopy, at resolving powers of up to 106 at 1 keV. Such optics should provide a revolutionary advance for high resolution lifetime free spectroscopy, such as RIXS, and for pulse compression of chirped beams. We report recent developmental fabrication and characterization of a prototype grating optimized for 14.2 nm EUV light. The prototype grating with a 200 nm period of the blazed grating substrate coated with 20 Mo/Si bilayers with a period of 7.1 nm demonstrates good dispersion in the third order (effective groove density of 15,000 lines per mm) with a diffraction efficiency of more than 33percent.
Date: September 16, 2009
Creator: Voronov, Dmitry L.; Cambie, Rossana; Ahn, Minseung; Anderson, Erik H.; Chang, Chih-Hao; Gullikson, Eric M. et al.
Object Type: Article
System: The UNT Digital Library
Microscopic Characterization of Carbonaceous Aerosol Particle Aging in the Outflow from Mexico City (open access)

Microscopic Characterization of Carbonaceous Aerosol Particle Aging in the Outflow from Mexico City

This study was part of the Megacities Initiative: Local and Global Research Observations (MILAGRO) field campaign conducted in Mexico City Metropolitan Area during spring 2006. The physical and chemical transformations of particles aged in the outflow from Mexico City were investigated for the transport event of 22 March 2006. A detailed chemical analysis of individual particles was performed using a combination of complementary microscopy and micro-spectroscopy techniques. The applied techniques included scanning transmission X-ray microscopy (STXM) coupled with near edge X-ray absorption fine structure spectroscopy (NEXAFS) and computer controlled scanning electron microscopy with an energy dispersive X-ray analyzer (CCSEM/EDX). As the aerosol plume evolves from the city center, the organic mass per particle increases and the fraction of carbon-carbon double bonds (associated with elemental carbon) decreases. Organic functional groups enhanced with particle age include: carboxylic acids, alkyl groups, and oxygen bonded alkyl groups. At the city center (T0) the most prevalent aerosol type contained inorganic species (composed of sulfur, nitrogen, oxygen, and potassium) coated with organic material. At the T1 and T2 sites, located northeast of T0 (~;;29 km and ~;;65 km, respectively), the fraction of homogenously mixed organic particles increased in both size and number. These observations illustrate the …
Date: September 16, 2009
Creator: Moffet, R. C.; Henn, T. R.; Tivanski, A. V.; Hopkins, R. J.; Desyaterik, Y.; Kilcoyne, A. L. D. et al.
Object Type: Article
System: The UNT Digital Library
On the Ionization Energies of C4H3 Isomers (open access)

On the Ionization Energies of C4H3 Isomers

We have conducted a combined experimental and theoretical study on the formation of distinct isomers of resonantly stabilized free radicals, C4H3, which are important intermediates in the formation of polycyclic aromatic hydrocarbons in combustion flames and possibly in the interstellar medium. Our study utilized laser ablation of graphite in combination with seeding the ablated species in neat methylacetylene gas which also acted as a reagent. Photoionization efficiency (PIE) curves were recorded of the C4H3 isomers at the Advanced Light Source from 8.0 to 10.3 eV. The experimental PIE curve was compared with theoretical ones suggesting the formation of four C4H3 radicals: two acyclic structures i-C4H3 [1] and E/Z-n-C4H3 [2E/2Z]and two cyclic isomers 3 and 4. These molecules are likely formed via an initial addition of ground state carbon atoms to the carbon-carbon triple bond of the methylacetylene molecule followed by isomerization via hydrogen migrations and ring opening and emission of atomic hydrogen from these intermediates.
Date: September 16, 2009
Creator: Kaiser, Ralf I.; Mebel, Alexander; Kostko, Oleg & Ahmed, Musahid
Object Type: Article
System: The UNT Digital Library
Biocorrosive Thermophilic Microbial Communities in Alaskan North Slope Oil Facilities (open access)

Biocorrosive Thermophilic Microbial Communities in Alaskan North Slope Oil Facilities

Corrosion of metallic oilfield pipelines by microorganisms is a costly but poorly understood phenomenon, with standard treatment methods targeting mesophilic sulfatereducing bacteria. In assessing biocorrosion potential at an Alaskan North Slope oil field, we identified thermophilic hydrogen-using methanogens, syntrophic bacteria, peptideand amino acid-fermenting bacteria, iron reducers, sulfur/thiosulfate-reducing bacteria and sulfate-reducing archaea. These microbes can stimulate metal corrosion through production of organic acids, CO2, sulfur species, and via hydrogen oxidation and iron reduction, implicating many more types of organisms than are currently targeted. Micromolar quantities of putative anaerobic metabolites of C1-C4 n-alkanes in pipeline fluids were detected, implying that these low molecular weight hydrocarbons, routinely injected into reservoirs for oil recovery purposes, are biodegraded and provide biocorrosive microbial communities with an important source of nutrients.
Date: September 16, 2009
Creator: Duncan, Kathleen E.; Gieg, Lisa M.; Parisi, Victoria A.; Tanner, Ralph S.; Green Tringe, Susannah; Bristow, Jim et al.
Object Type: Article
System: The UNT Digital Library