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Fine-scale Horizontal Structure of Arctic Mixed-Phase Clouds. (open access)

Fine-scale Horizontal Structure of Arctic Mixed-Phase Clouds.

Recent in situ observations in stratiform clouds suggest that mixed phase regimes, here defined as limited cloud volumes containing both liquid and solid water, are constrained to narrow layers (order 100 m) separating all-liquid and fully glaciated volumes (Hallett and Viddaurre, 2005). The Department of Energy Atmospheric Radiation Measurement Program's (DOE-ARM, Ackerman and Stokes, 2003) North Slope of Alaska (NSA) ARM Climate Research Facility (ACRF) recently started collecting routine measurement of radar Doppler velocity power spectra from the Millimeter Cloud Radar (MMCR). Shupe et al. (2004) showed that Doppler spectra has potential to separate the contributions to the total reflectivity of the liquid and solid water in the radar volume, and thus to investigate further Hallett and Viddaurre's findings. The Mixed-Phase Arctic Cloud Experiment (MPACE) was conducted along the NSA to investigate the properties of Arctic mixed phase clouds (Verlinde et al., 2006). We present surface based remote sensing data from MPACE to discuss the fine-scale structure of the mixed-phase clouds observed during this experiment.
Date: July 10, 2006
Creator: Rambukkange,M.; Verlinde, J.; Elorante, E.; Luke, E.; Kollias, P. & Shupe, M.
System: The UNT Digital Library
Chemical imaging of biological materials by NanoSIMS using isotopic and elemental labels (open access)

Chemical imaging of biological materials by NanoSIMS using isotopic and elemental labels

The NanoSIMS 50 combines unprecedented spatial resolution (as good as 50 nm) with ultra-high sensitivity (minimum detection limit of {approx}200 atoms). The NanoSIMS 50 incorporates an array of detectors, enabling simultaneous collection of 5 species originating from the same sputtered volume of a sample. The primary ion beam (Cs{sup +} or O{sup -}) can be scanned across the sample to produce quantitative secondary ion images. This capability for multiple isotope imaging with high spatial resolution provides a novel new approach to the study of biological materials. Studies can be made of sub-regions of tissues, mammalian cells, and bacteria. Major, minor and trace element distributions can be mapped on a submicron scale, growth and metabolism can be tracked using stable isotope labels, and biogenic origin can be determined based on composition. We have applied this technique extensively to mammalian and prokaryotic cells and bacterial spores. The NanoSIMS technology enables the researcher to interrogate the fate of molecules of interest within cells and organs through elemental and isotopic labeling. Biological applications at LLNL will be discussed.
Date: April 10, 2006
Creator: Weber, P K; Fallon, S J; Pett-Ridge, J; Ghosal, S & Hutcheon, I D
System: The UNT Digital Library
A review of the properties of Nb3Sn and their variation with A15composition, morphology and strain state (open access)

A review of the properties of Nb3Sn and their variation with A15composition, morphology and strain state

None
Date: November 10, 2006
Creator: Godeke, Arno
System: The UNT Digital Library
Power Corrections in Charmless Nonleptonic B Decays: Annihilationis Factorizable and Real (open access)

Power Corrections in Charmless Nonleptonic B Decays: Annihilationis Factorizable and Real

We classify {Lambda}{sub QCD}/m{sub b} power corrections to nonleptonic B {yields} M{sub 1}M{sub 2} decays, where M{sub 1,2} are charmless non-isosinglet mesons. Using recent developments in soft-collinear effective theory, we prove that the leading contributions to annihilation amplitudes of order {alpha}{sub s}(m{sub b}) {Lambda}{sub QCD}/m{sub b} are real. The leading annihilation amplitudes depend on twist-2 and the twist-3 three parton distributions. A complex nonperturbative parameter from annihilation first appears at {Omega}[{alpha}{sub s}{sup 2}({radical}{Lambda}m{sub b}){Lambda}{sub QCD}/m{sub b}]. 'Chirally enhanced' contributions are also factorizable and real at lowest order. Thus, incalculable strong phases are suppressed in annihilation amplitudes, unless the {alpha}{sub s}({radical}{Lambda}m{sub b}) expansion breaks down. Modeling the distribution functions, we find that (11 {+-} 9)% and (15 {+-} 11)% of the absolute values of the measured {bar B}{sup 0} {yields} K{sup -}{pi}{sup +} and B{sup -} {yields} K{sup -}K{sup 0} penguin amplitudes come from annihilation. This is consistent with the expected size of power corrections.
Date: October 10, 2006
Creator: Arnesen, Christian M.; Ligeti, Zoltan; Rothstein, Ira Z. & Stewart, Iain W.
System: The UNT Digital Library
Characterization of chemical bonding in low-k dielectric materialsfor interconnect isolation: a xas and eels study (open access)

Characterization of chemical bonding in low-k dielectric materialsfor interconnect isolation: a xas and eels study

The use of low dielectric constant materials in the on-chipinterconnect process reduces interconnect delay, power dissipation andcrosstalk noise. To achieve the requirements of the ITRS for 2007-2009minimal sidewall damage from etch, ash or cleans is required. In chemicalvapor deposited (CVD) organo-silicate glass (OSG) which are used asintermetal dielectric (IMD) materials the substitution of oxygen in SiO2by methyl groups (-CH3) reduces the permittivity significantly (from 4.0in SiO2 to 2.6-3.3 in the OSG), since the electronic polarizability islower for Si-C bonds than for Si-O bonds. However, plasma processing forresist stripping, trench etching and post-etch cleaning removes C and Hcontaining molecular groups from the near-surface layer of OSG.Therefore, compositional analysis and chemical bonding characterizationof structured IMD films with nanometer resolution is necessary forprocess optimization. OSG thin films as-deposited and after plasmatreatment are studied using X-ray absorption spectroscopy (XAS) andelectron energy loss spectroscopy (EELS). In both techniques, the finestructure near the C1s absorption or energy loss edge, respectively,allows to identify C-H, C-C, and C-O bonds. This gives the opportunity todifferentiate between individual low-k materials and their modifications.The O1s signal is less selective to individual bonds. XAS spectra havebeen recorded for non-patterned films and EELS spectra for patternedstructures. The chemical bonding is compared for as-deposited …
Date: April 10, 2006
Creator: Hoffmann, P.; Schmeisser, D.; Engelmann, H. J.; Zschech, E.; Stegmann, H.; Himpsel, F. et al.
System: The UNT Digital Library
Gel Electrophoresis of Gold-DNA Nano-Conjugates (open access)

Gel Electrophoresis of Gold-DNA Nano-Conjugates

Single stranded DNA of different lengths and different amounts was attached to colloidal phosphine stabilized Au nanoparticles. The resulting conjugates were investigated in detail by a gel electrophoresis study based on 1200 gels. We demonstrate how these experiments help to understand the binding of DNA to Au particles. In particular we compare specific attachment of DNA via gold-thiol bonds with nonspecific adsorption of DNA. The maximum number of DNA molecules that can be bound per particle was determined. We also compare several methods to used gel electrophoresis for investigating the effective diameter of DNA-Au conjugates, such as using a calibration curve of particles with known diameters and Ferguson plots.
Date: January 10, 2006
Creator: Pellegrino, T.; Sperling, R. A.; Alivisatos, A. P. & Parak, W. J.
System: The UNT Digital Library
The use of bulk states to accelerate the band edge statecalculation of a semiconductor quantum dot (open access)

The use of bulk states to accelerate the band edge statecalculation of a semiconductor quantum dot

We present a new technique to accelerate the convergence of the folded spectrum method in empirical pseudopotential band edge state calculations for colloidal quantum dots. We use bulk band states of the materials constituent of the quantum dot to construct initial vectors and a preconditioner. We apply these to accelerate the convergence of the folded spectrum method for the interior states at the top of the valence and the bottom of the conduction band. For large CdSe quantum dots, the number of iteration steps until convergence decreases by about a factor of 4 compared to previous calculations.
Date: May 10, 2006
Creator: Vomel, Christof; Tomov, Stanimire Z.; Wang, Lin-Wang; Marques,Osni A. & Dongarra, Jack J.
System: The UNT Digital Library
MODIFIED BOROHYDRIDES FOR REVERSIBLE HYDROGEN STORAGE (open access)

MODIFIED BOROHYDRIDES FOR REVERSIBLE HYDROGEN STORAGE

This paper reports the results in the effort to destabilize lithium borohydride for reversible hydrogen storage. A number of metals, metal hydrides, metal chlorides and complex hydrides were selected and evaluated as the destabilization agents for reducing dehydriding temperature and generating dehydriding-rehydriding reversibility. It is found that some additives are effective. The Raman spectroscopic analysis shows the change of B-H binding nature.
Date: May 10, 2006
Creator: Au, Ming
System: The UNT Digital Library
Bottom-up, decision support system development : a wetlandsalinity management application in California's San Joaquin Valley (open access)

Bottom-up, decision support system development : a wetlandsalinity management application in California's San Joaquin Valley

Seasonally managed wetlands in the Grasslands Basin ofCalifornia's San Joaquin Valley provide food and shelter for migratorywildfowl during winter months and sport for waterfowl hunters during theannual duck season. Surface water supply to these wetland contain saltwhich, when drained to the San Joaquin River during the annual drawdownperiod, negatively impacts downstream agricultural riparian waterdiverters. Recent environmental regulation, limiting discharges salinityto the San Joaquin River and primarily targeting agricultural non-pointsources, now addresses return flows from seasonally managed wetlands.Real-time water quality management has been advocated as a means ofmatching wetland return flows to the assimilative capacity of the SanJoaquin River. Past attempts to build environmental monitoring anddecision support systems to implement this concept have failed forreasons that are discussed in this paper. These reasons are discussed inthe context of more general challenges facing the successfulimplementation of environmental monitoring, modelling and decisionsupport systems. The paper then provides details of a current researchand development project which will ultimately provide wetland managerswith the means of matching salt exports with the available assimilativecapacity of the San Joaquin River, when fully implemented. Manipulationof the traditional wetland drawdown comes at a potential cost to thesustainability of optimal wetland moist soil plant habitat in thesewetlands - hence the project …
Date: May 10, 2006
Creator: Quinn, Nigel W.T.
System: The UNT Digital Library
Continuous active-source seismic monitoring of CO2 injection in abrine aquifer (open access)

Continuous active-source seismic monitoring of CO2 injection in abrine aquifer

Continuous crosswell seismic monitoring of a small-scale CO2injection was accomplished with the development of a noveltubing-deployed piezoelectric borehole source. This piezotube source wasdeployed on the CO2 injection tubing, near the top of the saline aquiferreservoir at 1657-m depth, and allowed acquisition of crosswellrecordings at 15-minute intervals during the multiday injection. Thechange in traveltime recorded at various depths in a nearby observationwell allowed hour-by-hour monitoring of the growing CO2 plume via theinduced seismic velocity change. Traveltime changes of 0.2 to 1.0 ms ( upto 8 percent ) were observed, with no change seen at control sensorsplaced above the reservoir. The traveltime measurements indicate that theCO2 plume reached the top of the reservoir sand before reaching theobservation well, where regular fluid sampling was occuring during theinjection, thus providing information about the in situ buoyancy ofCO2.
Date: December 10, 2006
Creator: Daley, Thomas M.; Solbau, Ray D.; Ajo-Franklin, Jonathan B. & Benson, Sally M.
System: The UNT Digital Library
THRESHOLD RESUMMATION FOR HIGGS PRODUCTION IN EFFECTIVE FIELD THEORY. (open access)

THRESHOLD RESUMMATION FOR HIGGS PRODUCTION IN EFFECTIVE FIELD THEORY.

None
Date: May 10, 2006
Creator: YUAN, F.
System: The UNT Digital Library
Brilliant Sm, Eu, Tb and Dy chiral lanthanide complexes withstrong circularly polarized luminescence (open access)

Brilliant Sm, Eu, Tb and Dy chiral lanthanide complexes withstrong circularly polarized luminescence

The synthesis, characterization and luminescent behavior of trivalent Sm, Eu, Dy and Tb complexes of two enantiomeric, octadentate, chiral, 2-hydroxyisophthalamide ligands are reported. These complexes are highly luminescent in solution. Functionalization of the achiral parent ligand with a chiral 1-phenylethylamine substituent on the open face of the complex in close proximity to the metal center yields complexes with strong circularly polarized luminescence (CPL) activity. This appears to be the first example of a system utilizing the same ligand architecture to sensitize four different lanthanide cations and display CPL activity. The luminescence dissymmetry factor, g{sub lum}, recorded for the Eu(III) complex is one of the highest values reported, and this is the first time the CPL effect has been demonstrated for a Sm(III) complex with a chiral ligand. The combination of high luminescence intensity with CPL activity should enable new bioanalytical applications of macromolecules in chiral environments.
Date: July 10, 2006
Creator: Petoud, Stephane; Muller, Gilles; Moore, Evan G.; Xu, Jide; Sokolnicki, Jurek; Riehl, James P. et al.
System: The UNT Digital Library
Multiple-code benchmark simulation study of coupled THMC processesin the excavation disturbed zone associated with geological nuclear wasterepositories (open access)

Multiple-code benchmark simulation study of coupled THMC processesin the excavation disturbed zone associated with geological nuclear wasterepositories

An international, multiple-code benchmark test (BMT) studyis being conducted within the international DECOVALEX project to analysecoupled thermal, hydrological, mechanical and chemical (THMC) processesin the excavation disturbed zone (EDZ) around emplacement drifts of anuclear waste repository. This BMT focuses on mechanical responses andlong-term chemo-mechanical effects that may lead to changes in mechanicaland hydrological properties in the EDZ. This includes time-de-pendentprocesses such as creep, and subcritical crack, or healing of fracturesthat might cause "weakening" or "hardening" of the rock over the longterm. Five research teams are studying this BMT using a wide range ofmodel approaches, including boundary element, finite element, and finitedifference, particle mechanics, and elasto-plastic cellular automatamethods. This paper describes the definition of the problem andpreliminary simulation results for the initial model inception part, inwhich time dependent effects are not yet included.
Date: May 10, 2006
Creator: Rutqvist, J.; Feng, X. T.; Hudson, J.; Jing, L.; Kobayashi, A.; Koyama, T. et al.
System: The UNT Digital Library
Solid Target Studies for Muon Colliders And Neutrino Beams (open access)

Solid Target Studies for Muon Colliders And Neutrino Beams

This paper presents preliminary results from an ongoing post-irradiation analysis of materials that have been irradiated at the Brookhaven National Laboratory (BNL) Isotope facility. The effort is part of an experimental study that focuses on how prone to irradiation damage these materials are and thus what is their potential in playing the role of high power targets in the neutrino superbeam and the muon collider initiatives.
Date: May 10, 2006
Creator: Simos, N.; Kirk, H.; Ludewig, H.; Thieberger, P.; Weng, W. T.; Trung, P. T. et al.
System: The UNT Digital Library
Why every national deep-geological-isolation program needs a long-term science & technology component (open access)

Why every national deep-geological-isolation program needs a long-term science & technology component

The objective of this paper is to set down the rationale for a separate Science & Technology (S&T) Program within every national deep-geological-isolation program. The fundamental rationale for such a Program is to provide a dedicated focus for longer-term science and technology activities that ultimately will benefit the whole repository mission. Such a Program, separately funded and with a dedicated staff (separate from the ''mainline'' activities to develop the repository, the surface facilities, and the transportation system), can devote itself exclusively to the development and management of a long-term science and technology program. Broad experience in governments worldwide has demonstrated that line offices are unlikely to be able to develop and sustain both the appropriate longer-term philosophy and the specialized skills associated with managing longer-term science and technology projects. Accomplishing both of these requires a separate dedicated program office with its own staff.
Date: February 10, 2006
Creator: Budnitz, R J
System: The UNT Digital Library
Supersymmetry, Naturalness, and Signatures at the LHC (open access)

Supersymmetry, Naturalness, and Signatures at the LHC

Weak scale supersymmetry is often said to be fine-tuned, especially if the matter content is minimal. This is not true if there is a large A term for the top squarks. We present a systematic study on fine-tuning in minimal supersymmetric theories and identify low energy spectra that do not lead to severe fine-tuning. Characteristic features of these spectra are: a large A term for the top squarks, small top squark masses, moderately large tan {beta}, and a small {mu} parameter. There are classes of theories leading to these features, which are discussed. In one class, which allows a complete elimination of fine-tuning, the Higgsinos are the lightest among all the superpartners of the standard model particles, leading to three nearly degenerate neutralino/chargino states. This gives interesting signals at the LHC--the dilepton invariant mass distribution has a very small endpoint and shows a particular shape determined by the Higgsino nature of the two lightest neutralinos. We demonstrate that these signals are indeed useful in realistic analyses by performing Monte Carlo simulations, including detector simulations and background estimations. We also present a method that allows the determination of all the relevant superparticle masses without using input from particular models, despite the …
Date: February 10, 2006
Creator: Kitano, Ryuichiro & Nomura, Yasunori
System: The UNT Digital Library
Detailed Chemical Kinetic Modeling of Cyclohexane Oxidation (open access)

Detailed Chemical Kinetic Modeling of Cyclohexane Oxidation

A detailed chemical kinetic mechanism has been developed and used to study the oxidation of cyclohexane at both low and high temperatures. Reaction rate constant rules are developed for the low temperature combustion of cyclohexane. These rules can be used for in chemical kinetic mechanisms for other cycloalkanes. Since cyclohexane produces only one type of cyclohexyl radical, much of the low temperature chemistry of cyclohexane is described in terms of one potential energy diagram showing the reaction of cyclohexyl radical + O{sub 2} through five, six and seven membered ring transition states. The direct elimination of cyclohexene and HO{sub 2} from RO{sub 2} is included in the treatment using a modified rate constant of Cavallotti et al. Published and unpublished data from the Lille rapid compression machine, as well as jet-stirred reactor data are used to validate the mechanism. The effect of heat loss is included in the simulations, an improvement on previous studies on cyclohexane. Calculations indicated that the production of 1,2-epoxycyclohexane observed in the experiments can not be simulated based on the current understanding of low temperature chemistry. Possible 'alternative' H-atom isomerizations leading to different products from the parent O{sub 2}QOOH radical were included in the low temperature …
Date: November 10, 2006
Creator: Silke, E J; Pitz, W J; Westbrook, C K & Ribaucour, M
System: The UNT Digital Library
Longitudinal double-spin asymmetry and cross section for inclusivejet production in polarized proton collisions at sqrt(s) = 200 GeV (open access)

Longitudinal double-spin asymmetry and cross section for inclusivejet production in polarized proton collisions at sqrt(s) = 200 GeV

We report a measurement of the longitudinal double-spinasymmetry A_LL and the differential cross section for inclusivemidrapidity jet production in polarized proton collisions at sqrt(s)=200GeV. The cross section data cover transverse momenta 5<pT<50GeV/c and agree with next-to-leading order perturbative QCD evaluations.The A_LL data cover 5<pT<17 GeV/c and disfavor at 98 percentC.L. maximal positive gluon polarization in the polarizednucleon.
Date: August 10, 2006
Creator: Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
System: The UNT Digital Library
Comparative simulation study of coupled THM processes nearback-filled and open-drift nuclear waste repositories in Task D of theInternational DECOVALEX Project (open access)

Comparative simulation study of coupled THM processes nearback-filled and open-drift nuclear waste repositories in Task D of theInternational DECOVALEX Project

As part of the ongoing international DECOVALEX project, fourresearch teams used five different models to simulate coupled thermal,hydrological, and mechanical (THM) processes near underground wasteemplacement drifts. The simulations were conducted for two genericrepository types, one with open and the other with back-filled repositorydrifts, under higher and lower post-closure temperature, respectively. Inthe completed first model inception phase of the project, a goodagreement was achieved between the research teams in calculating THMresponses for both repository types, although some disagreement inhydrological responses are currently being resolved. Good agreement inthe basic thermal-mechanical responses was also achieved for bothrepository types, even though some teams used relatively simplifiedthermal-elastic heat-conduction models that neglect complex near-fieldthermal-hydrological processes. The good agreement between the complexand simplified process models indicates that the basic thermal-mechanicalresponses can be predicted with a relatively high confidencelevel.
Date: May 10, 2006
Creator: Rutqvist, J.; Birkholzer, J.T.; Chijimatsu, M.; Kolditz, O.; Liu,Quan-Sheng; Oda, Y. et al.
System: The UNT Digital Library
Microanalytical Methods for Bio-Forensics Investigations (open access)

Microanalytical Methods for Bio-Forensics Investigations

Forensics investigations of bio-crime or bio-terrorism incidents require careful analysis of collected evidentiary material. Although the biological markers in the evidentiary material are important (e.g. genomic signatures, protein markers), the elemental make-up of the organisms themselves and the surrounding non-biological material is extremely useful for attributing a specific process and, perhaps, specific persons to the production of the biological agent. This talk will describe the coordinated use of microanalytical techniques such as SEM-EDX, STEM-EDX, and NanoSIMS for generating compositional signatures for bio-forensics investigations. These analytical techniques span length scales from the 50 {micro}m range to the 5nm range. The range of analytical sensitivities spans from {approx}.5wt% for EDX down to parts per billion for SIMS techniques. In addition, we will discuss the use of spectrum imaging techniques for rapidly extracting the key elemental signatures from large scale data sets. Spectrum imaging techniques combined with multivariate statistical analysis allow for the collection and interrogation or enormous quantities of data without pre-biasing the answer.[1] Spectrum imaging has been used successfully in EDX microanalysis[1] (both in the SEM and TEM) and TOF-SIMS[2]. In this study, a set of test biological agents, ?-irradiated Bacillus thuringiensis (Bt), were examined using the aforementioned microanalytical techniques. The …
Date: February 10, 2006
Creator: Brewer, L N; Weber, P K; Grant, R P; Ghosal, S & Michael, J R
System: The UNT Digital Library
Calculating the Muon Cooling within a MICE Solid and Liquid Absorber (open access)

Calculating the Muon Cooling within a MICE Solid and Liquid Absorber

The key elements of the Muon Ionization Cooling Experiment (MICE) cooling channel are the absorbers that are a part of the MICE absorber focus coil modules (AFC modules). The boundaries of room temperature solid absorbers are well defined. The density of most solid absorber materials is also well understood. The properties of solid absorber are most certainly understood to 0.3 percent. The MICE liquid absorbers are different in that their dimensions are a function of the absorber temperature and the fluid pressure within the absorber. The second element in the liquid absorber is the variability of the liquid density with temperature and pressure. While one can determine the absorber boundary within 0.3 percent, the determination of the liquid density within 0.3 percent is more difficult (particularly with liquid helium in the absorber). This report presents a method of calculating absorber boundary and the cooling performance of the MICE absorbers as a function of fluid temperature and pressure.
Date: June 10, 2006
Creator: Yang, Stephanie Q.; Green, Michael A. & Virostek, Steve P.
System: The UNT Digital Library
Impacts of Future Climate Change on California Perennial Crop Yields: Model Projections with Climate and Crop Uncertainties (open access)

Impacts of Future Climate Change on California Perennial Crop Yields: Model Projections with Climate and Crop Uncertainties

Most research on the agricultural impacts of climate change has focused on the major annual crops, yet perennial cropping systems are less adaptable and thus potentially more susceptible to damage. Improved assessments of yield responses to future climate are needed to prioritize adaptation strategies in the many regions where perennial crops are economically and culturally important. These impact assessments, in turn, must rely on climate and crop models that contain often poorly defined uncertainties. We evaluated the impact of climate change on six major perennial crops in California: wine grapes, almonds, table grapes, oranges, walnuts, and avocados. Outputs from multiple climate models were used to evaluate climate uncertainty, while multiple statistical crop models, derived by resampling historical databases, were used to address crop response uncertainties. We find that, despite these uncertainties, climate change in California is very likely to put downward pressure on yields of almonds, walnuts, avocados, and table grapes by 2050. Without CO{sub 2} fertilization or adaptation measures, projected losses range from 0 to &gt;40% depending on the crop and the trajectory of climate change. Climate change uncertainty generally had a larger impact on projections than crop model uncertainty, although the latter was substantial for several crops. Opportunities …
Date: January 10, 2006
Creator: Lobell, D; Field, C; Cahill, K & Bonfils, C
System: The UNT Digital Library
Electric Field Assisted Assembly of Perpendicular Oriented NanorodSuperlattices (open access)

Electric Field Assisted Assembly of Perpendicular Oriented NanorodSuperlattices

We observe the assembly of CdS nanorod superlattices by thecombination of a DC electric field and solvent evaporation. In eachelectric field (1 V/um) assisted assembly, CdS nanorods (5 x 30 nm)suspended initially in toluene were observed to align perpendicularly tothe substrate. Azimuthal alignment along the nanorod crystal faces andthe presence of stacking faults indicate that both 2D and 3D assemblieswere formed by a process of controlled super crystal growth.
Date: April 10, 2006
Creator: Ryan, Kevin M.; Mastroianni, Alex; Stancil, Kimani A.; Liu,Haitao & Alivisatos, A. P.
System: The UNT Digital Library
The Cold Mass Support System and the Helium Cooling System for the MICE Focusing Solenoid (open access)

The Cold Mass Support System and the Helium Cooling System for the MICE Focusing Solenoid

The heart of the absorber focus coil (AFC) module for the muon ionization cooling experiment (MICE) is the two-coil superconducting solenoid that surrounds the muon absorber. The superconducting magnet focuses the muons that are cooled using ionization cooling, in order to improve the efficiency of cooling. The coils of the magnet may either be run in the solenoid mode (both coils operate at the same polarity) or the gradient (the coils operate at opposite polarity). The AFC magnet cold mass support system is designed to carry a longitudinal force up to 700 kN. The AFC module will be cooled using three pulse tube coolers that produce 1.5 W of cooling at 4.2 K. One of the coolers will be used to cool the liquid (hydrogen or helium) absorber used for ionization cooling. The other two coolers will cool the superconducting solenoid. This report will describe the MICE AFC magnet. The cold mass supports will be discussed. The reasons for using a pulsed tube cooler to cool this superconducting magnet will also be discussed.
Date: August 10, 2006
Creator: Yang, Stephanie Q.; Green, Michael A.; Lau, Wing W.; Senanayake,Rohan S. & Witte, Holger
System: The UNT Digital Library