Toward fully self-consistent simulation of the interaction of E-Clouds and beams with WARP-POSINST (open access)

Toward fully self-consistent simulation of the interaction of E-Clouds and beams with WARP-POSINST

To predict the evolution of electron clouds and their effect on the beam, the high energy physics community has relied so far on the complementary use of 'buildup' and 'single/multi-bunch instability' reduced descriptions. The former describes the evolution of electron clouds at a given location in the ring, or 'station', under the influence of prescribed beams and external fields [1], while the latter (sometimes also referred as the 'quasi-static' approximation [2]) follows the interaction between the beams and the electron clouds around the accelerator with prescribed initial distributions of electrons, assumed to be concentrated at a number of discrete 'stations' around the ring. Examples of single bunch instability codes include HEADTAIL [3], QuickPIC [4, 5], and PEHTS [6]. By contrast, a fully self-consistent approach, in which both the electron cloud and beam distributions evolve simultaneously under their mutual influence without any restriction on their relative motion, is required for modeling the interaction of high-intensity beams with electron clouds for heavy-ion beam-driven fusion and warm-dense matter science. This community has relied on the use of Particle-In-Cell (PIC) methods through the development and use of the WARP-POSINST code suite [1, 7, 8]. The development of novel numerical techniques (including adaptive mesh refinement, …
Date: April 9, 2012
Creator: Lawrence Livermore National Laboratory
Object Type: Article
System: The UNT Digital Library
Can Ionic Liquids Be Used As Templating Agents For Controlled Design of Uranium-Containing Nanomaterials? (open access)

Can Ionic Liquids Be Used As Templating Agents For Controlled Design of Uranium-Containing Nanomaterials?

Nanostructured uranium oxides have been prepared in ionic liquids as templating agents. Using the ionic liquids as reaction media for inorganic nanomaterials takes advantage of the pre-organized structure of the ionic liquids which in turn controls the morphology of the inorganic nanomaterials. Variation of ionic liquid cation structure was investigated to determine the impact on the uranium oxide morphologies. For two ionic liquid cations, increasing the alkyl chain length increases the aspect ratio of the resulting nanostructured oxides. Understanding the resulting metal oxide morphologies could enhance fuel stability and design.
Date: April 9, 2013
Creator: Visser, A.; Bridges, N. & Tosten, M.
Object Type: Article
System: The UNT Digital Library
Model-Independent Results for the Decay B \to L Nu(L) Gamma at BaBar (open access)

Model-Independent Results for the Decay B \to L Nu(L) Gamma at BaBar

We present a search for the radiative leptonic decays B{sub +} {yields} e{sup +} {nu}{sub e}{gamma} and B{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}{gamma} using data collected by the BABAR detector at the PEP-II B factory. We fully reconstruct the hadronic decay of one of the B mesons in {Upsilon}(4S) {yields} B{sup +}B{sup -} and then search for evidence of the signal decay within the rest of the event. This method provides clean kinematic information on the signal's missing energy and high momentum photon and lepton, and allows for a model-independent analysis of this decay. Using a data sample of 465 million B-meson pairs, we obtain sensitivity to branching fractions of the same order as predicted by the Standard Model. We report a model-independent branching fraction upper limit of {Beta}(B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}}{gamma}) < 15.6 x 10{sup -6} ({ell} = e or {mu}) at the 90% confidence level.
Date: April 9, 2012
Creator: Lindemann, D. M.
Object Type: Article
System: The UNT Digital Library
Experimental Demonstration of Femtosecond Two-Color X-Ray Free-Electron Lasers (open access)

Experimental Demonstration of Femtosecond Two-Color X-Ray Free-Electron Lasers

None
Date: April 9, 2013
Creator: Lutman, A. A.; Coffee, R.; Ding, Y.; Huang, Z.; Krzywinski, J.; Maxwell, T. et al.
Object Type: Article
System: The UNT Digital Library
Lepton-Flavor-Violating Tau Decays at BaBar (open access)

Lepton-Flavor-Violating Tau Decays at BaBar

We present the most recent searches for lepton-flavor-violating (LFV) {tau} decays in BABAR. We find no evidence of {tau} decaying to three charged leptons or to a charged lepton and a neutral meson (K{sub S}{sup 0}, {rho}, {phi}, K*{sup 0}, {bar K}*{sup 0}), and set upper limits on the corresponding branching fractions (BF) between 1.8 and 19 x 10{sup -8} at 90% confidence level (CL).
Date: April 9, 2012
Creator: Marchiori, G. & /Paris, LPTHE
Object Type: Article
System: The UNT Digital Library
Next-to-Leading Order W 5-Jet Production at the LHC (open access)

Next-to-Leading Order W 5-Jet Production at the LHC

None
Date: April 9, 2013
Creator: Bern, Z.; Dixon, L. J.; Cordero, F. Febres; Hoeche, S.; Ita, H.; Kosower, D. A. et al.
Object Type: Article
System: The UNT Digital Library
Future Synchrotron Light Sources Based on Ultimate Storage Rings (open access)

Future Synchrotron Light Sources Based on Ultimate Storage Rings

The main purpose of this talk is to describe how far one might push the state of the art in storage ring design. The talk will start with an overview of the latest developments and advances in the design of synchrotron light sources based on the concept of an 'ultimate' storage ring. The review will establish how bright a ring based light source might be, where the frontier of technological challenges are, and what the limits of accelerator physics are. Emphasis will be given to possible improvements in accelerator design and developments in technology toward the goal of achieving an ultimate storage ring. An ultimate storage ring (USR), defined as an electron ring-based light source having an emittance in both transverse planes at the diffraction limit for the range of X-ray wavelengths of interest for a scientific community, would provide very high brightness photons having high transverse coherence that would extend the capabilities of X-ray imaging and probe techniques beyond today's performance. It would be a cost-effective, high-coherence 4th generation light source, competitive with one based on energy recovery linac (ERL) technology, serving a large number of users studying material, chemical, and biological sciences. Furthermore, because of the experience accumulated …
Date: April 9, 2012
Creator: Cai, Yunhai
Object Type: Article
System: The UNT Digital Library
Laboratory Directed Research and Development Annual Report for 2011 (open access)

Laboratory Directed Research and Development Annual Report for 2011

This report documents progress made on all LDRD-funded projects during fiscal year 2011. The following topics are discussed: (1) Advanced sensors and instrumentation; (2) Biological Sciences; (3) Chemistry; (4) Earth and space sciences; (5) Energy supply and use; (6) Engineering and manufacturing processes; (7) Materials science and technology; (8) Mathematics and computing sciences; (9) Nuclear science and engineering; and (10) Physics.
Date: April 9, 2012
Creator: Hughes, Pamela J.
Object Type: Report
System: The UNT Digital Library
Letter Report for Characterization of Biochar (open access)

Letter Report for Characterization of Biochar

On 27 November 2012, a bulk biochar sample was received for characterization of selected physical and chemical properties. The main purpose of the characterization was to help determine the degree to which biochar would be suitable as a soil amendment to aid in growth of plants. Towards this end, analyses to determine specific surface, pH, cation-exchange capacity, water retention, and wettability (i.e. surface tension) were conducted. A second objective was to determine how uniform these properties were in the sample. Towards this end, the sample was separated into fractions based on initial particle size and on whether the material was from the external surface or the internal portion of the particle. Based on the results, the biochar has significant liming potentials, significant cation-retention capacities, and highly variable plant-available moisture retention properties that, under the most favorable circumstances, could be helpful to plants. As a consequence, it would be quite suitable for addition to acidic soils and should enhance the fertility of those soils.
Date: April 9, 2013
Creator: Amonette, James E.
Object Type: Report
System: The UNT Digital Library
Multimodality Imaging with Silica-Based Targeted Nanoparticle Platforms (open access)

Multimodality Imaging with Silica-Based Targeted Nanoparticle Platforms

Objectives: To synthesize and characterize a C-Dot silica-based nanoparticle containing 'clickable' groups for the subsequent attachment of targeting moieties (e.g., peptides) and multiple contrast agents (e.g., radionuclides with high specific activity) [1,2]. These new constructs will be tested in suitable tumor models in vitro and in vivo to ensure maintenance of target-specificity and high specific activity. Methods: Cy5 dye molecules are cross-linked to a silica precursor which is reacted to form a dye-rich core particle. This core is then encapsulated in a layer of pure silica to create the core-shell C-Dot (Figure 1) [2]. A 'click' chemistry approach has been used to functionalize the silica shell with radionuclides conferring high contrast and specific activity (e.g. 64Cu and 89Zr) and peptides for tumor targeting (e.g. cRGD and octreotate) [3]. Based on the selective Diels-Alder reaction between tetrazine and norbornene, the reaction is bioorthogonal, highyielding, rapid, and water-compatible. This radiolabeling approach has already been employed successfully with both short peptides (e.g. octreotate) and antibodies (e.g. trastuzumab) as model systems for the ultimate labeling of the nanoparticles [1]. Results: PEGylated C-Dots with a Cy5 core and labeled with tetrazine have been synthesized (d = 55 nm, zeta potential = -3 mV) reliably and …
Date: April 9, 2012
Creator: Lewis, Jason S.
Object Type: Report
System: The UNT Digital Library
Scientific Final Report: COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT (open access)

Scientific Final Report: COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT

This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAG's advanced dynamics core with the 'physics' of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer-reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited.
Date: April 9, 2012
Creator: Gutowski, William J. & Joseph M. Prusa, Piotr K. Smolarkiewicz
Object Type: Report
System: The UNT Digital Library
Missing Energy and Jets for Supersymmetry Searches (open access)

Missing Energy and Jets for Supersymmetry Searches

None
Date: April 9, 2013
Creator: Bern, Z.; Diana, G.; Dixon, L. J.; Febres Cordero, F.; Hoeche, S.; Ita, H. et al.
Object Type: Article
System: The UNT Digital Library
Nuclear Weapons and Material Security (WMS) Team Program Review (WMS2013 CdTeSe Crystals for Gamma-Ray Detectors (open access)

Nuclear Weapons and Material Security (WMS) Team Program Review (WMS2013 CdTeSe Crystals for Gamma-Ray Detectors

N/A
Date: April 9, 2013
Creator: U., Roy
Object Type: Article
System: The UNT Digital Library
High Energy Electron Signals from Dark Matter Annihilation in the Sun (open access)

High Energy Electron Signals from Dark Matter Annihilation in the Sun

In this paper we discuss two mechanisms by which high energy electrons resulting from dark matter annihilations in or near the Sun can arrive at the Earth. Specifically, electrons can escape the sun if DM annihilates into long-lived states, or if dark matter scatters inelastically, which would leave a halo of dark matter outside of the sun. Such a localized source of electrons may affect the spectra observed by experiments with narrower fields of view oriented towards the sun, such as ATIC, differently from those with larger fields of view such as Fermi. We suggest a simple test of these possibilities with existing Fermi data that is more sensitive than limits from final state radiation. If observed, such a signal will constitute an unequivocal signature of dark matter.
Date: April 9, 2012
Creator: Schuster, Philip; Toro, Natalia; Weiner, Neal & Yavin, Itay
Object Type: Article
System: The UNT Digital Library
CdTeSe Crystals for Gamma-Ray Detectors (open access)

CdTeSe Crystals for Gamma-Ray Detectors

N/A
Date: April 9, 2013
Creator: U., Roy; James, R. B.; Kim, K. H. & Bolotnikov, A. E.
Object Type: Article
System: The UNT Digital Library
LCLS Accelerator Operation and Measurement of Electron Beam Parameters Relevant for the X-ray Beam (open access)

LCLS Accelerator Operation and Measurement of Electron Beam Parameters Relevant for the X-ray Beam

None
Date: April 9, 2013
Creator: Loos, Henrik
Object Type: Article
System: The UNT Digital Library
Application of Stochastic Radiative Transfer Theory to the ARM Cloud-Radiative Parameterization Problem (open access)

Application of Stochastic Radiative Transfer Theory to the ARM Cloud-Radiative Parameterization Problem

This project had two primary goals: (1) development of stochastic radiative transfer as a parameterization that could be employed in an AGCM environment, and (2) exploration of the stochastic approach as a means for representing shortwave radiative transfer through mixed-phase layer clouds. To achieve these goals, climatology of cloud properties was developed at the ARM CART sites, an analysis of the performance of the stochastic approach was performed, a simple stochastic cloud-radiation parameterization for an AGCM was developed and tested, a statistical description of Arctic mixed phase clouds was developed and the appropriateness of stochastic approach for representing radiative transfer through mixed-phase clouds was assessed. Significant progress has been made in all of these areas and is detailed in the final report.
Date: April 9, 2012
Creator: Veron, Dana E.
Object Type: Report
System: The UNT Digital Library
Formalism for Neutron Cross Section Covariances in the Resonance Region Using Kernel Approximation (open access)

Formalism for Neutron Cross Section Covariances in the Resonance Region Using Kernel Approximation

We describe analytical formalism for estimating neutron radiative capture and elastic scattering cross section covariances in the resolved resonance region. We use capture and scattering kernels as the starting point and show how to get average cross sections in broader energy bins, derive analytical expressions for cross section sensitivities, and deduce cross section covariances from the resonance parameter uncertainties in the recently published Atlas of Neutron Resonances. The formalism elucidates the role of resonance parameter correlations which become important if several strong resonances are located in one energy group. Importance of potential scattering uncertainty as well as correlation between potential scattering and resonance scattering is also examined. Practical application of the formalism is illustrated on {sup 55}Mn(n,{gamma}) and {sup 55}Mn(n,el).
Date: April 9, 2010
Creator: Oblozinsky, P.; Cho, Y-S.; Matoon, C. M. & Mughabghab, S. F.
Object Type: Report
System: The UNT Digital Library
Femtosecond x-ray free electron laser pulse duration measurement from spectral correlation function (open access)

Femtosecond x-ray free electron laser pulse duration measurement from spectral correlation function

None
Date: April 9, 2013
Creator: Lutman, A. A.; Ding, Y.; Feng, Y.; Huang, Z.; Messerschmidt, M.; Wu, J. et al.
Object Type: Article
System: The UNT Digital Library
Array of Virtual Frisch-Grid CZT Detectors with Common Cathode Readout for Correcting Charge Trapping and Rejecting Incomplete Charge Collection (open access)

Array of Virtual Frisch-Grid CZT Detectors with Common Cathode Readout for Correcting Charge Trapping and Rejecting Incomplete Charge Collection

N/A
Date: April 9, 2013
Creator: A., Bolotnikov
Object Type: Article
System: The UNT Digital Library
Studies of Charmonium-Like States at BaBar (open access)

Studies of Charmonium-Like States at BaBar

Several charmonium-like states above D{bar D} threshold have been discovered at the Belle and BABAR B-factories. Some of these states are produced via Initial State Radiation (e.g. Y(4260) and Y(4350)), and some are observed in B-meson decays (e.g. X(3872), and Y(3940)). The Belle observations of the enhancements in the {Psi}(2S){pi}{sup -} and {chi}{sub cl}{pi}{sup -}, i.e. the Z(4430){sup -}, Z{sub 1}(4050){sup -}, and Z{sub 2}(4250){sup -}, have generated a great deal of interest, because such states must have minimum quark content (c{bar c}d{bar u}), i.e. these are four-quark states. The BABAR Collaboration does not confirm the existence of the Z(4430){sup -}.
Date: April 9, 2012
Creator: Mokhtar, Arafat Gabareen
Object Type: Article
System: The UNT Digital Library
QCD Matrix Elements + Parton Showers: The NLO Case (open access)

QCD Matrix Elements + Parton Showers: The NLO Case

None
Date: April 9, 2013
Creator: Hoeche, Stefan; Krauss, Frank; Schonherr, Marek & Siegert, Frank
Object Type: Article
System: The UNT Digital Library
Unveiling the Nature of the Unidentified Gamma-ray Sources II: Radio, Infrared and Optical Counterparts of the gamma-ray Blazar Candidates (open access)

Unveiling the Nature of the Unidentified Gamma-ray Sources II: Radio, Infrared and Optical Counterparts of the gamma-ray Blazar Candidates

None
Date: April 9, 2013
Creator: Massaro, F.; D'Abrusco, R.; Paggi, A.; Masetti, N.; Giroletti, M.; Tosti, G. et al.
Object Type: Article
System: The UNT Digital Library