SLUDGE BATCH 6/TANK 51 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS (open access)

SLUDGE BATCH 6/TANK 51 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS

Qualification simulant testing was completed to determine appropriate processing conditions and assumptions for the Sludge Batch 6 (SB6) Shielded Cells demonstration of the DWPF flowsheet using the qualification sample from Tank 51 for SB6 after SRNL washing. It was found that an acid addition window of 105-139% of the DWPF acid equation (100-133% of the Koopman minimum acid equation) gave acceptable Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) results for nitrite destruction and hydrogen generation. Hydrogen generation occurred continuously after acid addition in three of the four tests. The three runs at 117%, 133%, and 150% stoichiometry (Koopman) were all still producing around 0.1 lb hydrogen/hr at DWPF scale after 42 hours of boiling in the SRAT. The 150% acid run reached 110% of the DWPF SRAT limit of 0.65 lb H{sub 2}/hr, and the 133% acid run reached 75% of the DWPF SME limit of 0.223 lb H{sub 2}/hr. Conversely, nitrous oxide generation was subdued compared to previous sludge batches, staying below 25 lb/hr in all four tests or about a fourth as much as in comparable SB4 testing. Two other processing issues were noted. First, incomplete mercury suspension impacted mercury stripping from the SRAT …
Date: April 28, 2010
Creator: Koopman, David & Best, David
Object Type: Report
System: The UNT Digital Library
YALINA Facility a Sub-Critical Accelerator- Driven System (Ads) for Nuclear Energy Research Facility Description and an Overview of the Research Program (1997-2008). (open access)

YALINA Facility a Sub-Critical Accelerator- Driven System (Ads) for Nuclear Energy Research Facility Description and an Overview of the Research Program (1997-2008).

The YALINA facility is a zero-power, sub-critical assembly driven by a conventional neutron generator. It was conceived, constructed, and put into operation at the Radiation Physics and Chemistry Problems Institute of the National Academy of Sciences of Belarus located in Minsk-Sosny, Belarus. This facility was conceived for the purpose of investigating the static and dynamic neutronics properties of accelerator driven sub-critical systems, and to serve as a neutron source for investigating the properties of nuclear reactions, in particular transmutation reactions involving minor-actinide nuclei. This report provides a detailed description of this facility and documents the progress of research carried out there during a period of approximately a decade since the facility was conceived and built until the end of 2008. During its history of development and operation to date (1997-2008), the YALINA facility has hosted several foreign groups that worked with the resident staff as collaborators. The participation of Argonne National Laboratory in the YALINA research programs commenced in 2005. For obvious reasons, special emphasis is placed in this report on the work at YALINA facility that has involved Argonne's participation. Attention is given here to the experimental program at YALINA facility as well as to analytical investigations aimed at …
Date: April 28, 2010
Creator: Gohar, Y. & Smith, D. L.
Object Type: Report
System: The UNT Digital Library
Quantum Phase Extraction in Isospectral Electronic Nanostructures (open access)

Quantum Phase Extraction in Isospectral Electronic Nanostructures

Quantum phase is not a direct observable and is usually determined by interferometric methods. We present a method to map complete electron wave functions, including internal quantum phase information, from measured single-state probability densities. We harness the mathematical discovery of drum-like manifolds bearing different shapes but identical resonances, and construct quantum isospectral nanostructures possessing matching electronic structure but divergent physical structure. Quantum measurement (scanning tunneling microscopy) of these 'quantum drums' [degenerate two-dimensional electron states on the Cu(111) surface confined by individually positioned CO molecules] reveals that isospectrality provides an extra topological degree of freedom enabling robust quantum state transplantation and phase extraction.
Date: April 28, 2010
Creator: Moon, Christopher
Object Type: Article
System: The UNT Digital Library
SLUDGE BATCH 6/TANK 40 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS (open access)

SLUDGE BATCH 6/TANK 40 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS

None
Date: April 28, 2010
Creator: Koopman, David
Object Type: Report
System: The UNT Digital Library
Quantum Detection and Invisibility in Coherent Nanostructures (open access)

Quantum Detection and Invisibility in Coherent Nanostructures

We address quantum invisibility in the context of electronics in nanoscale quantum structures. In analogy with metamaterials, we use the freedom of design that quantum corrals provide and show that quantum mechanical objects can be hidden inside the corral, with respect to inelastic electron scattering spectroscopy in combination with scanning tunneling microscopy, and we propose a design strategy. A simple illustration of the invisibility is given in terms of an elliptic quantum corral containing a molecule, with a local vibrational mode, at one of the foci. Our work has implications to quantum information technology and presents new tools for nonlocal quantum detection and distinguishing between different molecules.
Date: April 28, 2010
Creator: Fransson, J.
Object Type: Article
System: The UNT Digital Library
Non-diffusive spin dynamics in a two-dimensional electron gas (open access)

Non-diffusive spin dynamics in a two-dimensional electron gas

We describe measurements of spin dynamics in the two-dimensional electron gas in GaAs/GaAlAs quantum wells. Optical techniques, including transient spin-grating spectroscopy, are used to probe the relaxation rates of spin polarization waves in the wavevector range from zero to 6 x 10{sup 4} cm{sup -1}. We find that the spin polarization lifetime is maximal at nonzero wavevector, in contrast with expectation based on ordinary spin diffusion, but in quantitative agreement with recent theories that treat diffusion in the presence of spin-orbit coupling.
Date: April 28, 2010
Creator: Weber, C.P.
Object Type: Article
System: The UNT Digital Library
Single-Atom Gating of Quantum State Superpositions (open access)

Single-Atom Gating of Quantum State Superpositions

The ultimate miniaturization of electronic devices will likely require local and coherent control of single electronic wavefunctions. Wavefunctions exist within both physical real space and an abstract state space with a simple geometric interpretation: this state space - or Hilbert space - is spanned by mutually orthogonal state vectors corresponding to the quantized degrees of freedom of the real-space system. Measurement of superpositions is akin to accessing the direction of a vector in Hilbert space, determining an angle of rotation equivalent to quantum phase. Here we show that an individual atom inside a designed quantum corral1 can control this angle, producing arbitrary coherent superpositions of spatial quantum states. Using scanning tunnelling microscopy and nanostructures assembled atom-by-atom we demonstrate how single spins and quantum mirages can be harnessed to image the superposition of two electronic states. We also present a straightforward method to determine the atom path enacting phase rotations between any desired state vectors. A single atom thus becomes a real-space handle for an abstract Hilbert space, providing a simple technique for coherent quantum state manipulation at the spatial limit of condensed matter.
Date: April 28, 2010
Creator: Moon, Christopher
Object Type: Article
System: The UNT Digital Library
SLUDGE BATCH 6/TANK 40 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS (open access)

SLUDGE BATCH 6/TANK 40 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS

Phase III simulant flowsheet testing was completed using the latest composition estimates for SB6/Tank 40 feed to DWPF. The goals of the testing were to determine reasonable operating conditions and assumptions for the startup of SB6 processing in the DWPF. Testing covered the region from 102-159% of the current DWPF stoichiometric acid equation. Nitrite ion concentration was reduced to 90 mg/kg in the SRAT product of the lowest acid run. The 159% acid run reached 60% of the DWPF Sludge Receipt and Adjustment Tank (SRAT) limit of 0.65 lb H2/hr, and then sporadically exceeded the DWPF Slurry Mix Evaporator (SME) limit of 0.223 lb H2/hr. Hydrogen generation rates peaked at 112% of the SME limit, but higher than targeted wt% total solids levels may have been partially responsible for rates seen. A stoichiometric factor of 120% met both objectives. A processing window for SB6 exists from 102% to something close to 159% based on the simulant results. An initial recommendation for SB6 processing is at 115-120% of the current DWPF stoichiometric acid equation. The addition of simulated Actinide Removal Process (ARP) and Modular Caustic Side Solvent Extraction Unit (MCU) streams to the SRAT cycle had no apparent impact on the …
Date: April 28, 2010
Creator: Koopman, David
Object Type: Report
System: The UNT Digital Library
Centroid and Envelope Dynamics of High-intensity Charged Particle Beams in an External Focusing Lattice and Oscillating Wobbler (open access)

Centroid and Envelope Dynamics of High-intensity Charged Particle Beams in an External Focusing Lattice and Oscillating Wobbler

The centroid and envelope dynamics of a high-intensity charged particle beam are investigated as a beam smoothing technique to achieve uniform illumination over a suitably chosen region of the target for applications to ion-beam-driven high energy density physics and heavy ion fusion. The motion of the beam centroid projected onto the target follows a smooth pattern to achieve the desired illumination, for improved stability properties during the beam-target interaction. The centroid dynamics is controlled by an oscillating "wobbler", a set of electrically-biased plates driven by RF voltage. __________________________________________________
Date: April 28, 2010
Creator: Qin, Hong; Davidson, Ronald C. & Logan, B. Grant
Object Type: Report
System: The UNT Digital Library
Science & Technology Review June 2010 (open access)

Science & Technology Review June 2010

This month's issue has the following articles: (1) A Leader in High-Pressure Science--Commentary by William H. Goldstein; (2) Diamonds Put the Pressure on Materials--New experimental capabilities are helping Livermore scientists better understand how extreme pressure affects a material's structure; (3) Exploring the Unusual Behavior of Granular Materials--Livermore scientists are developing new techniques for predicting the response of granular materials under pressure; (4) A 1-Ton Device in a Briefcase--A new briefcase-sized tool for nuclear magnetic resonance is designed for onsite analysis of suspected chemical weapons; and (5) Targets Designed for Ignition--A series of experiments at the National Ignition Facility is helping scientists finalize the ignition target design.
Date: April 28, 2010
Creator: Blobaum, K. J.
Object Type: Report
System: The UNT Digital Library
Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons (open access)

Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons

Neutralization and focusing of intense charged particle beam pulses by electrons forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self- magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic …
Date: April 28, 2010
Creator: Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P. et al.
Object Type: Report
System: The UNT Digital Library
Assessment of China's Energy-Saving and Emission-Reduction Accomplishments and Opportunities During the 11th Five Year Plan (open access)

Assessment of China's Energy-Saving and Emission-Reduction Accomplishments and Opportunities During the 11th Five Year Plan

During the period 1980 to 2002, China experienced a 5% average annual reduction in energy consumption per unit of gross domestic product (GDP). The period 2002-2005 saw a dramatic reversal of the historic relationship between energy use and GDP growth: energy use per unit of GDP increased an average of 3.8% per year during this period (NBS, various years). China's 11th Five Year Plan (FYP), which covers the period 2006-2010, required all government divisions at different levels to reduce energy intensity by 20% in five years in order to regain the relationship between energy and GDP growth experienced during the 1980s and 1990s. This report provides an assessment of selected policies and programs that China has instituted in its quest to fulfill the national goal of a 20% reduction in energy intensity by 2010. The report finds that China has made substantial progress toward its goal of achieving 20% energy intensity reduction from 2006 to 2010 and that many of the energy-efficiency programs implemented during the 11th FYP in support of China's 20% energy/GDP reduction goal appear to be on track to meet - or in some cases even exceed - their energy-saving targets. It appears that most of the …
Date: April 28, 2010
Creator: Levine, Mark D.; Price, Lynn; Zhou, Nan; Fridley, David; Aden, Nathaniel; Lu, Hongyou et al.
Object Type: Report
System: The UNT Digital Library
Status Summary of 3He and Neutron Detection Alternatives for Homeland Security (open access)

Status Summary of 3He and Neutron Detection Alternatives for Homeland Security

This is a short summary whitepaper on results of our alternatives work: Neutron detection is an important aspect of interdiction of radiological threats for homeland security purposes since plutonium, a material used for nuclear weapons, is a significant source of fission neutrons [Kouzes 2005]. Because of the imminent shortage of 3He, which is used in the most commonly deployed neutron detectors, a replacement technology for neutron detection is required for most detection systems in the very near future [Kouzes 2009a]. For homeland security applications, neutron false alarms from a detector can result in significant impact. This puts a strong requirement on any neutron detection technology not to generate false neutron counts in the presence of a large gamma ray-only source [Kouzes et al. 2008].
Date: April 28, 2010
Creator: Kouzes, Richard T. & Ely, James H.
Object Type: Report
System: The UNT Digital Library
Semiconductor Nanowires: What's Next? (open access)

Semiconductor Nanowires: What's Next?

In this perspective, we take a critical look at the research progress within the nanowire community for the past decade. We discuss issues on the discovery of fundamentally new phenomena versus performance benchmarking for many of the nanowire applications. We also notice that both the bottom-up and top-down approaches have played important roles in advancing our fundamental understanding of this new class of nanostructures. Finally we attempt to look into the future and offer our personal opinions on what the future trends will be in nanowire research.
Date: April 28, 2010
Creator: Yang, Peidong; Yan, Ruoxue & Fardy, Melissa
Object Type: Article
System: The UNT Digital Library
Phytoremediation of ionic and methylmercury pollution (open access)

Phytoremediation of ionic and methylmercury pollution

Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and sequester the toxic elemental pollutants, like the heavy metal mercury. Our current working hypothesis is that transgenic plants controlling the transport, chemical speciation, electrochemical state. volatilization, and aboveground binding of mercury will: a) tolerate mercury and grow rapidly in mercury contaminated environments; b) prevent methylmercury from entering the food chain; c) remove mercury from polluted soil and . water; and d) hyperaccumulate mercury in aboveground tissues for later harvest. Progress toward these specific aims is reported: to increase the transport of mercury into roots and to aboveground vegetative organs; to increase biochemical sinks and storage for mercury in leaves; to increase leaf cell vacuolar storage of mercury; and to demonstrate that several stacked transgenes, when functioning in concert, enhance mercury resistance and hyperaccumulation to high levels.
Date: April 28, 2010
Creator: Meagher, Richard B
Object Type: Report
System: The UNT Digital Library
Measurement of the gamma gamma* to eta_c transition form factor (open access)

Measurement of the gamma gamma* to eta_c transition form factor

The authors study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -} {eta}{sub c}, {eta}{sub c} {yields} K{sub S}K{sup {+-}}{pi}{sup {-+}} and obtain {eta}{sub c} mass and width values 2982.2 {+-} 0.4 {+-} 1.6 MeV/c{sup 2} and 31.7 {+-} 1.2 {+-} 0.8 MeV, respectively. They find {Lambda}({eta}{sub c} {yields} {gamma}{gamma}){Beta}({eta}{sub c} {yields} K{bar K}{pi}) = 0.374 {+-} 0.009 {+-} 0.031 keV, and measure the {gamma}{gamma}* {yields} {eta}{sub c} transition form factor in the momentum transfer range from 2 to 50 GeV{sup 2}. The analysis is based on 469 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.
Date: April 28, 2010
Creator: Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E. et al.
Object Type: Article
System: The UNT Digital Library