The BigBoss Experiment (open access)

The BigBoss Experiment

BigBOSS is a Stage IV ground-based dark energy experiment to study baryon acoustic oscillations (BAO) and the growth of structure with a wide-area galaxy and quasar redshift survey over 14,000 square degrees. It has been conditionally accepted by NOAO in response to a call for major new instrumentation and a high-impact science program for the 4-m Mayall telescope at Kitt Peak. The BigBOSS instrument is a robotically-actuated, fiber-fed spectrograph capable of taking 5000 simultaneous spectra over a wavelength range from 340 nm to 1060 nm, with a resolution R = {lambda}/{Delta}{lambda} = 3000-4800. Using data from imaging surveys that are already underway, spectroscopic targets are selected that trace the underlying dark matter distribution. In particular, targets include luminous red galaxies (LRGs) up to z = 1.0, extending the BOSS LRG survey in both redshift and survey area. To probe the universe out to even higher redshift, BigBOSS will target bright [OII] emission line galaxies (ELGs) up to z = 1.7. In total, 20 million galaxy redshifts are obtained to measure the BAO feature, trace the matter power spectrum at smaller scales, and detect redshift space distortions. BigBOSS will provide additional constraints on early dark energy and on the curvature of …
Date: June 7, 2012
Creator: Schelgel, D.; Abdalla, F.; Abraham, T.; Ahn, C.; Allende Prieto, C.; Annis, J. et al.
System: The UNT Digital Library
Broad Line Radio Galaxies Observed with Fermi-LAT: The Origin of the GeV Gamma-Ray Emission (open access)

Broad Line Radio Galaxies Observed with Fermi-LAT: The Origin of the GeV Gamma-Ray Emission

We report on a detailed investigation of the {gamma}-ray emission from 18 broad line radio galaxies (BLRGs) based on two years of Fermi Large Area Telescope (LAT) data. We confirm the previously reported detections of 3C 120 and 3C 111 in the GeV photon energy range; a detailed look at the temporal characteristics of the observed {gamma}-ray emission reveals in addition possible flux variability in both sources. No statistically significant {gamma}-ray detection of the other BLRGs was however found in the considered dataset. Though the sample size studied is small, what appears to differentiate 3C 111 and 3C 120 from the BLRGs not yet detected in {gamma}-rays is the particularly strong nuclear radio flux. This finding, together with the indications of the {gamma}-ray flux variability and a number of other arguments presented, indicate that the GeV emission of BLRGs is most likely dominated by the beamed radiation of relativistic jets observed at intermediate viewing angles. In this paper we also analyzed a comparison sample of high accretion-rate Seyfert 1 galaxies, which can be considered radio-quiet counterparts of BLRGs, and found none were detected in {gamma}-rays. A simple phenomenological hybrid model applied for the broad-band emission of the discussed radio-loud and …
Date: June 7, 2012
Creator: Kataoka, J.; Stawarz, L.; Takahashi, Y.; Cheung, C. C.; Hayashida, M.; Grandi, P. et al.
System: The UNT Digital Library
Color-kinematics duality and double-copy construction for amplitudes from higher-dimension operators (open access)

Color-kinematics duality and double-copy construction for amplitudes from higher-dimension operators

None
Date: August 7, 2012
Creator: Broedel, Johannes & Dixon, Lance J.
System: The UNT Digital Library
Design and assembly of a telecentric zoom lens for the Cygnus x-ray source (open access)

Design and assembly of a telecentric zoom lens for the Cygnus x-ray source

Our goal is to collect x-ray images of different sized targets, which are positioned inside a containment vessel, onto different sized CCD cameras.
Date: August 7, 2012
Creator: Malone, R M; Brown, K K; Curtis, A H; Esquibel, D L; Frayer, D K; Frogget, B C et al.
System: The UNT Digital Library
Diagnostic options for radiative divertor feedback control on NSTX-U (open access)

Diagnostic options for radiative divertor feedback control on NSTX-U

None
Date: May 7, 2012
Creator: Soukhanovskii, V A; Gerhardt, S P; Kaita, R; McLean, A G & Raman, R
System: The UNT Digital Library
Direct Hadron Production in Hadronic Collisions (open access)

Direct Hadron Production in Hadronic Collisions

None
Date: June 7, 2012
Creator: Arleo, Francois; Brodsky, Stanley J.; Hwang, Dae Sung & Sickles, Anne M.
System: The UNT Digital Library
Discovery of Very High Energy Gamma-Ray Emission from 1FGL J2001.1 4351 by MAGIC (open access)

Discovery of Very High Energy Gamma-Ray Emission from 1FGL J2001.1 4351 by MAGIC

We report the discovery of Very High Energy (VHE; >100 GeV) gamma-ray emission from the source 1FGL J2001.1+4351, (RA 20 01 13.5, dec 43 53 02.8, J2000), which is positionally consistent with the location of the flat spectrum radio source MG4 J200112+4352 (RA 20 01 12.9, dec 43 52 52.8, J2000). The VHE detection is based on a 1.5 hour-long observation performed on July 16th in stereoscopic mode with the two 17m diameter imaging Cherenkov telescopes on La Palma, Canary Islands, Spain. The preliminary analysis of the MAGIC data using the standard cuts optimized for soft energy spectra sources yields a detection of 125 gamma-rays above 90 GeV, corresponding to a pre-trail statistical significance of 7.6 standard deviations. The observed flux is estimated to be {approx}20% of the Crab nebula flux above 100 GeV. Earlier MAGIC observations indicated a substantially lower flux; hence indicating that the source is variable on a few days timescale.
Date: May 7, 2012
Creator: Berger, Karsten; Paneque, David & Giavitto, Gianluca
System: The UNT Digital Library
Empirical Model for Formulation of Crystal-Tolerant Hlw Glasses (open access)

Empirical Model for Formulation of Crystal-Tolerant Hlw Glasses

Historically, high-level waste (HLW) glasses have been formulated with a low liquideus temperature (T{sub L}), or temperature at which the equilibrium fraction of spinel crystals in the melt is below 1 vol % (T{sub 0.01}), nominally below 1050 C. These constraints cannot prevent the accumulation of large spinel crystals in considerably cooler regions ({approx} 850 C) of the glass discharge riser during melter idling and significantly limit the waste loading, which is reflected in a high volume of waste glass, and would result in high capital, production, and disposal costs. A developed empirical model predicts crystal accumulation in the riser of the melter as a function of concentration of spinel-forming components in glass, and thereby provides guidance in formulating crystal-tolerant glasses that would allow high waste loadings by keeping the spinel crystals small and therefore suspended in the glass.
Date: March 7, 2012
Creator: Kruger, A. A.; Matyas, J.; Huckleberry, A. R.; Vienna, J. D. & Rodriguez, C. A.
System: The UNT Digital Library
Enhanced NIF Neutron Activation Diagnostics (open access)

Enhanced NIF Neutron Activation Diagnostics

None
Date: May 7, 2012
Creator: Yeamans, C B; Bleuel, D L & Bernstein, L A
System: The UNT Digital Library
The Evaluation of the Heat Loading from Steady, Transient, and Off-Normal Conditions in ARIES Power Plants (open access)

The Evaluation of the Heat Loading from Steady, Transient, and Off-Normal Conditions in ARIES Power Plants

The heat loading on plasma facing components (PFCs) provides a critical limitation for design and operation of the first wall, divertor, and other special components. Power plants will have high power entering the scrape-off layer and transporting to the first wall and divertor. Although the design for steady heat loads is understood, the approach for transient and offnormal loading is not. The characterization of heat loads developed for ITER1 can be applied to power plants to better develop the operating space of viable solutions and point to research focus areas.
Date: September 7, 2012
Creator: C.E. Kessel, M.S. Tillack and J. Blanchard
System: The UNT Digital Library
Experimental techniques for measuring Rayleigh-Taylor instability in inertial confinement fusion (ICF) (open access)

Experimental techniques for measuring Rayleigh-Taylor instability in inertial confinement fusion (ICF)

Rayleigh-Taylor (RT) instability is one of the major concerns in inertial confinement fusion (ICF) because it amplifies target modulations in both acceleration and deceleration phases of implosion, which leads to shell disruption and performance degradation of imploding targets. This article reviews experimental results of the RT growth experiments performed on OMEGA laser system, where targets were driven directly with laser light. RT instability was studied in the linear and nonlinear regimes. The experiments were performed in acceleration phase, using planar and spherical targets, and in deceleration phase of spherical implosions, using spherical shells. Initial target modulations consisted of 2-D pre-imposed modulations, and 2-D and 3-D modulations imprinted on targets by the non-uniformities in laser drive. In planar geometry, the nonlinear regime was studied using 3-D modulations with broadband spectra near nonlinear saturation levels. In acceleration-phase, the measured modulation Fourier spectra and nonlinear growth velocities are in good agreement with those predicted by Haan's model [Haan S W 1989 Phys. Rev. A 39 5812]. In a real-space analysis, the bubble merger was quantified by a self-similar evolution of bubble size distributions [Oron D et al 2001 Phys. Plasmas 8, 2883]. The 3-D, inner-surface modulations were measured to grow throughout the deceleration …
Date: June 7, 2012
Creator: Smalyuk, V A
System: The UNT Digital Library
Explosive Pulsed Power Experimental Capability at LLNL (open access)

Explosive Pulsed Power Experimental Capability at LLNL

None
Date: November 7, 2012
Creator: White, A. D.; Milhous, D. P.; Goerz, D. A.; Anderson, R. A.; Ferriera, T. J.; Speer, R. D. et al.
System: The UNT Digital Library
A Fixed-Target ExpeRiment at the LHC (AFTER@LHC) : Luminosities, Target Polarisation and a Selection of Physics Studies (open access)

A Fixed-Target ExpeRiment at the LHC (AFTER@LHC) : Luminosities, Target Polarisation and a Selection of Physics Studies

None
Date: August 7, 2012
Creator: Lansberg, J.P.; Chambert, V.; Didelez, J.P.; Genolini, B.; Hadjidakis, C.; Rosier, P. et al.
System: The UNT Digital Library
Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus eXperiment divertor (open access)

Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus eXperiment divertor

None
Date: May 7, 2012
Creator: Scotti, F; Roquemore, A L & Soukhanovskii, V A
System: The UNT Digital Library
Gluons and the Quark Sea at High Energies: Distributions, Polarization, Tomography (open access)

Gluons and the Quark Sea at High Energies: Distributions, Polarization, Tomography

This report on the science case for an Electron-Ion Collider (EIC) is the result of a ten-week program at the Institute for Nuclear Theory (INT) in Seattle (from September 13-November 19, 2010), motivated by the need to develop a strong case for the continued study of the QCD description of hadron structure in the coming decades. Hadron structure in the valence quark region will be studied extensively with the Jefferson Lab 12 GeV science program, the subject of an INT program the previous year. The focus of the INT program was on understanding the role of gluons and sea quarks, the important dynamical degrees of freedom describing hadron structure at high energies. Experimentally, the most direct and precise way to access the dynamical structure of hadrons and nuclei at high energies is with a high luminosity lepton probe in collider mode. An EIC with optimized detectors offers enormous potential as the next generation accelerator to address many of the most important, open questions about the fundamental structure of matter. The goal of the INT program, as captured in the writeups in this report, was to articulate these questions and to identify golden experiments that have the greatest potential to provide …
Date: June 7, 2012
Creator: Boer, Daniel; Diehl, Markus; Milner, Richard; Venugopalan, Raju; Vogelsang, Werner; Kaplan, David et al.
System: The UNT Digital Library
High Accuracy U-235 Enrichment Verification Station for Low Enriched Uranium Alloys (open access)

High Accuracy U-235 Enrichment Verification Station for Low Enriched Uranium Alloys

The Y-12 National Security Complex is playing a role in the U.S. High Performance Research Reactor (USHPRR) Conversion program sponsored by the U.S. National Nuclear Security Administration's Office of Global Threat Reduction. The USHPRR program has a goal of converting remaining U.S. reactors that continue to use highly enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. The USHPRR program is currently developing a LEU Uranium-Molybdenum (U-Mo) monolithic fuel for use in the U.S. high performance research reactors.Y-12 is supporting both the fuel development and fuel fabrication efforts by fabricating low enriched U-Mo foils from its own source material for irradiation experiments and for optimizing the fabrication process in support of scaling up the process to a commercial production scale. Once the new fuel is qualified, Y-12 will produce and ship U-Mo coupons with verified 19.75% +0.2% - 0.3% U-235 enrichment to be fabricated into fuel elements for the USHPRRs. Considering this small enrichment tolerance and the transition into HEU being set strictly at 20% U-235, a characterization system with a measurement uncertainty of less than or equal to 0.1% in enrichment is desired to support customer requirements and minimize production costs. Typical uncertainty for most available characterization systems …
Date: June 7, 2012
Creator: Lillard, C. R.; Hayward, J. P. & Williamson, M. R.
System: The UNT Digital Library
An Investigation of X-ray Luminosity versus Crystalline Powder Granularity (open access)

An Investigation of X-ray Luminosity versus Crystalline Powder Granularity

At the High-throughput Discovery of Scintillator Materials Facility at Lawrence Berkeley National Laboratory, scintillators are synthesized by solid-state reaction or melt mixing, forming crystalline powders. These powders are formed in various granularity and the crystal grain size affects the apparent luminosity of the scintillator. To accurately predict a "full-size" scintillator's crystal luminosity, the crystal luminosity as a function of crystal granularity size has to be known. In this study, we examine Bi{sub 4}Ge{sub 3}O{sub 12} (BGO), Lu{sub 2}SiO{sub 5}:Ce (LSO), YAlO{sub 3}:Ce (YAP:Ce), and CsBa{sub 2}I{sub 5}:Eu{sup 2+} (CBI) luminosities as a function of crystalline grain size. The highest luminosities were measured for 600- to 1000-{micro}m crystal grain sizes for BGO and LSO, for 310- to 600-{micro}m crystal grain sizes for CBI, and for crystal grains larger than 165{micro}m for YAP:Ce. Crystal grains that were larger than 1 mm had a lower packing fraction, and smaller grains were affected by internal scattering. We measured a 34% decrease in luminosity for BGO when decreasing from the 600- to 1000- {micro}m crystal grain size range down to the 20- to 36-{micro}m range. The corresponding luminosity decrease for LSO was 44% for the same grain size decrease. YAP:Ce exhibited a luminosity decrease of …
Date: March 7, 2012
Creator: Borade, Ramesh & Bourret-Courchesne, Edith
System: The UNT Digital Library
The Klynac: An Integrated Klystron and Linear Accelerator (open access)

The Klynac: An Integrated Klystron and Linear Accelerator

The Klynac concept integrates an electron gun, a radio frequency (RF) power source, and a coupled-cavity linear accelerator into a single resonant system
Date: August 7, 2012
Creator: Potter, J. M., Schwellenbach, D., Meidinger, A.
System: The UNT Digital Library
MELTING OF GLASS BATCH - MODEL FOR MULTIPLE OVERLAPPING GAS-EVOLVING REACTIONS (open access)

MELTING OF GLASS BATCH - MODEL FOR MULTIPLE OVERLAPPING GAS-EVOLVING REACTIONS

In this study, we present a model for the kinetics of multiple overlapping reactions. Mathematical representation of the kinetics of gas-evolving reactions is crucial for the modeling of the feed-to-glass conversion in a waste-glass melter. The model simulates multiple gas-evolving reactions that occur during heating of a high-alumina high-level waste melter feed. To obtain satisfactory kinetic parameters, we employed Kissinger's method combined with least-squares analysis. The power-law kinetics with variable reaction order sufficed for obtaining excellent agreement with measured thermogravimetric analysis data.
Date: February 7, 2012
Creator: Kruger, A. A.; Pierce, D. A.; Pokorny, R. & Hrma, P. R.
System: The UNT Digital Library
Mulard: A Multigroup Thermal Radiation Diffusion Mini-Application (open access)

Mulard: A Multigroup Thermal Radiation Diffusion Mini-Application

None
Date: March 7, 2012
Creator: Brunner, T A
System: The UNT Digital Library
The NIF 4.5-m nTOF Detectors (open access)

The NIF 4.5-m nTOF Detectors

The first several campaigns of laser fusion experiments at the National Ignition Facility (NIF) included a family of high-sensitivity scintillator/photodetector neutron-time-of-flight (nTOF) detectors for measuring DD and DT neutron yields. The detectors provided consistent neutron yield benchmarks from below 1E9 (DD) to nearly 1E15 (DT). The detectors demonstrated DT yield measurement precisions better than 5%, but the absolute accuracy relies on cross calibration with independent measurements of absolute neutron yield. The 4.5-m nTOF data have provided a useful testbed for testing improvements in nTOF data processing, especially with respect to improving the accuracies of the detector impulse response functions. The resulting improvements in data analysis methods have produced more accurate results. In summary, results from the NIF 4.5-m nTOF detectors have provided consistent measurements of DD and DT neutron yields from laser-fusion implosions.
Date: May 7, 2012
Creator: Moran, M. J.; Bond, E. J.; Clancy, T. J.; Eckart, M. J.; Khater, H. Y. & Glebov, V. Y.
System: The UNT Digital Library
Nuclear Plasma Interactions on NIF (open access)

Nuclear Plasma Interactions on NIF

None
Date: November 7, 2012
Creator: Hoffman, R; Zimmerman, G; Chen, M & Cerjan, C
System: The UNT Digital Library
Opposed Port Alignment System (OPAS): A Commercial Astronomical Telescope Modified for Viewing the Interior of the NIF Target Chamber (open access)

Opposed Port Alignment System (OPAS): A Commercial Astronomical Telescope Modified for Viewing the Interior of the NIF Target Chamber

None
Date: August 7, 2012
Creator: Manuel, A M; McCarville, T J; Seppala, L G; Klingmann, J L & Kalantar, D H
System: The UNT Digital Library
RAPID RADIOCHEMICAL ANALYSES IN SUPPORT OF FUKUSHIMA NUCLEAR ACCIDENT (open access)

RAPID RADIOCHEMICAL ANALYSES IN SUPPORT OF FUKUSHIMA NUCLEAR ACCIDENT

There is an increasing need to develop faster analytical methods for emergency response, including emergency soil and air filter samples. The Savannah River National Laboratory (SRNL) performed analyses on samples received from Japan in April, 2011 as part of a U.S. Department of Energy effort to provide assistance to the government of Japan, following the nuclear event at Fukushima Daiichi, resulting from the earthquake and tsunami on March 11, 2011. Of particular concern was whether it was safe to plant rice in certain areas (prefectures) near Fukushima. The primary objectives of the sample collection, sample analysis, and data assessment teams were to evaluate personnel exposure hazards, identify the nuclear power plant radiological source term and plume deposition, and assist the government of Japan in assessing any environmental and agricultural impacts associated with the nuclear event. SRNL analyzed approximately 250 samples and reported approximately 500 analytical method determinations. Samples included soil from farmland surrounding the Fukushima reactors and air monitoring samples of national interest, including those collected at the U.S. Embassy and American military bases. Samples were analyzed for a wide range of radionuclides, including strontium-89, strontium-90, gamma-emitting radionuclides, and plutonium, uranium, americium and curium isotopes. Technical aspects of the rapid …
Date: November 7, 2012
Creator: Maxwell, S.
System: The UNT Digital Library