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Control of beam dynamics in high energy induction linacs

Description: The Advent of laser-ion-guiding in the Advanced test Accelerator along with the development of accelerator cavities optimized with respect to beam breakup coupling impedence now make it possible to consider a new class of high current, high emergy linear induction accelerators. The control of the beam breakup and other instabilities by laser guiding and by various magnetic focusing schemes will be discussed along with the scaling laws for the design of such machines to minimize the growth of th… more
Date: July 29, 1986
Creator: Caporaso, G.J.
Partner: UNT Libraries Government Documents Department
open access

TMX tandem-mirror experiments and thermal-barrier theoretical studies

Description: This paper describes recent analysis of energy confinement in the Tandem Mirror Experiment (TMX). TMX data also indicates that warm plasma limits the amplitude of the anisotropy driven Alfven ion cyclotron (AIC) mode. Theoretical calculations show strong AIC stabilization with off-normal beam injection as planned in TMX-U and MFTF-B. This paper reports results of theoretical analysis of hot electrons in thermal barriers including electron heating calculations by Monte Carlo and Fokker-Planck co… more
Date: July 29, 1982
Creator: Simonen, T. C.; Baldwin, D. E. & Allen, S. L.
Partner: UNT Libraries Government Documents Department
open access

TMX tandem-mirror experiments and thermal-barrier theoretical studies

Description: This paper describes recent analysis of energy confinement in the Tandem Mirror Experiment (TMX). TMX data also indicates that warm plasma limits the amplitude of the anisotropy driven Alfven ion cyclotron (AIC) mode. Theoretical calculations show strong AIC stabilization with off-normal beam injection as planned in TMX-U and MFTF-B. This paper reports results of theoretical analysis of hot electrons in thermal barriers including electron heating calculations by Monte Carlo and Fokker-Planck co… more
Date: July 29, 1982
Creator: Simonen, T. C.; Baldwin, D. E. & Allen, S. L.
Partner: UNT Libraries Government Documents Department
open access

Rh(I)-Catalyzed Direct Arylation of Pyridines and Quinolines

Description: The pyridine and quinoline nuclei are privileged scaffolds that occupy a central role in many medicinally relevant compounds. Consequently, methods for their expeditious functionalization are of immediate interest. However, despite the immense importance of transition-metal catalyzed cross-coupling for the functionalization of aromatic scaffolds, general solutions for coupling 2-pyridyl organometallics with aryl halides have only recently been presented. Direct arylation at the ortho position o… more
Date: July 29, 2008
Creator: Berman, Ashley; Lewis, Jared; Bergman, Robert & Ellman, Jonathan
Partner: UNT Libraries Government Documents Department
open access

Direct Photons at RHIC

Description: Direct photons are ideal tools to investigate kinematical and thermodynamical conditions of heavy ion collisions since they are emitted from all stages of the collision and once produced they leave the interaction region without further modification by the medium. The PHENIX experiment at RHIC has measured direct photon production in p+p and Au+Au collisions at 200 GeV over a wide transverse momentum (p{sub T}) range. The p+p measurements allow a fundamental test of QCD, and serve as a baseline… more
Date: July 29, 2008
Creator: Gabor,D.
Partner: UNT Libraries Government Documents Department
open access

The Little Randall-Sundrum Model at the LHC

Description: We present a predictive warped model of flavor, cut off at an ultraviolet scale {Omicron}(10{sup 3}) TeV, called the 'Little Randall-Sundrum (LRS)' model. This model corresponds to a volume-truncation, by a factor y {approx} 6, of the RS scenario and is holographically dual to dynamics with number of colors larger by y. With separate gauge and flavor dynamics, several unwanted contributions to precision electroweak, Zb{bar b}, and flavor observables are suppressed in the LRS framework, compared… more
Date: July 29, 2008
Creator: Davoudiasl, H.
Partner: UNT Libraries Government Documents Department
open access

Roll compaction and granulation system for nuclear fuel material

Description: A roll compaction and roll granulation system has been designed and fabricated to replace conventional preslugging and crushing operations typically used in the fabrication of mixed oxide nuclear fuel pellets. This equipment will be of maintenance advantage with only the compaction and granulation rolls inside containment. The prototype is being tested and the results will be reported within a year.
Date: July 29, 1981
Creator: Goldmann, L.H. Jr. & Holley, C.C.
Partner: UNT Libraries Government Documents Department
open access

Remarks to panel discussion on new machines

Description: The discussion centers on the energies and luminosities required to reach a 1 TeV mass scale. Several bellwether experiments are discussed, involving either momentum transfers or new classes of particles. (GHT)
Date: July 29, 1982
Creator: Palmer, Robert B.
Partner: UNT Libraries Government Documents Department
open access

NOVEL INTEGRATING SOLID STATE DETECTOR WITH SEGMENTATION FOR SCANNING TRANSMISSION SOFT X-RAY MICROSCOPY.

Description: An integrating solid state detector with segmentation has been developed that addresses the needs in scanning transmission x-ray microscopy below 1 keV photon energy. The detector is not cooled and can be operated without an entrance window which leads to a total photon detection efficiency close to 100%. The chosen segmentation with 8 independent segments is matched to the geometry of the STXM to maximize image mode flexibility. In the bright field configuration for 1 ms integration time and 5… more
Date: July 29, 2001
Creator: FESER,M. JACOBSEN,C. REHAK,P. DE GERONIMO,G. HOLL,P. STUDER,L.
Partner: UNT Libraries Government Documents Department
open access

Propagation of rarefaction pulses in particulate materials with strain-softening behavior

Description: We investigate rarefaction waves in nonlinear periodic systems with a 'softening' power-law relationship between force and displacement to understand the dynamic behavior of this class of materials. A closed form expression describing the shape of the strongly nonlinear rarefaction wave is exact for n = 1/2 and agrees well with the shape and width of the pulses resulting from discrete simulations. A chain of particles under impact was shown to propagate a rarefaction pulse as the leading pulse … more
Date: July 29, 2011
Creator: Herbold, E B & Nesterenko, V F
Partner: UNT Libraries Government Documents Department
open access

FastQuery: A Parallel Indexing System for Scientific Data

Description: Modern scientific datasets present numerous data management and analysis challenges. State-of-the- art index and query technologies such as FastBit can significantly improve accesses to these datasets by augmenting the user data with indexes and other secondary information. However, a challenge is that the indexes assume the relational data model but the scientific data generally follows the array data model. To match the two data models, we design a generic mapping mechanism and implement an e… more
Date: July 29, 2011
Creator: Chou, Jerry; Wu, Kesheng & Prabhat,
Partner: UNT Libraries Government Documents Department
open access

2011 Clusters, Nanocrystals & Nanostructures Gordon Research Conference

Description: Small particles have been at the heart of nanoscience since the birth of the field and now stand ready to make significant contributions to the big challenges of energy, health and sustainability. Atomic clusters show exquisite size-dependent electronic and magnetic properties and offer a new level of control in catalyses, sensors and biochips; functionalised nanocrystals offer remarkable optical properties and diverse applications in electronic devices, solar energy, and therapy. Both areas ar… more
Date: July 29, 2011
Creator: Wang, Lai-Sheng
Partner: UNT Libraries Government Documents Department
open access

Surface core-level binding energy shifts for MgO(100)

Description: This article presents theoretical and experimental results for the surface core-level binding energy, BE, shifts, SCLS, for MgO(100) and the anomalous O(1s) SCLS is interpreted in terms of the surface electronic structure.
Date: July 29, 2014
Creator: Nelin, Connie J.; Uhl, Felix; Staemmler, Volker; Bagus, Paul S.; Fujimori, Yuichi; Sterrer, Martin et al.
Partner: UNT College of Arts and Sciences
open access

Overview of the SuperNova/Acceleration probe (SNAP)

Description: The SuperNova/Acceleration Probe (SNAP) is a space-based experiment to measure the expansion history of the Universe and study both its dark energy and the dark matter. The experiment is motivated by the startling discovery that the expansion of the Universe is accelerating. A 0.7 square-degree imager comprised of 36 large format fully-depleted n-type CCD's sharing a focal plane with 36 HgCdTe detectors forms the heart of SNAP, allowing discovery and lightcurve measurements simultaneously for m… more
Date: July 29, 2002
Creator: galdering@lbl.gov
Partner: UNT Libraries Government Documents Department
open access

SNAP Telescope

Description: The SuperNova/Acceleration Probe (SNAP) mission will require a two-meter class telescope delivering diffraction limited images spanning a one degree field in the visible and near infrared wavelength regime. This requirement, equivalent to nearly one billion pixel resolution, places stringent demands on its optical system in terms of field flatness, image quality, and freedom from chromatic aberration. We discuss the advantages of annular-field three-mirror anastigmat (TMA) telescopes for applic… more
Date: July 29, 2002
Creator: Lampton, Michael L.; Akerlof, C. W.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E. et al.
Partner: UNT Libraries Government Documents Department
open access

Accelerating Network Traffic Analytics Using Query-DrivenVisualization

Description: Realizing operational analytics solutions where large and complex data must be analyzed in a time-critical fashion entails integrating many different types of technology. This paper focuses on an interdisciplinary combination of scientific data management and visualization/analysis technologies targeted at reducing the time required for data filtering, querying, hypothesis testing and knowledge discovery in the domain of network connection data analysis. We show that use of compressed bitmap in… more
Date: July 29, 2006
Creator: Bethel, E. Wes; Campbell, Scott; Dart, Eli; Stockinger, Kurt & Wu,Kesheng
Partner: UNT Libraries Government Documents Department
open access

Stable transmission of radio frequency signals on fiber links using interferomectric delay sensing

Description: The authors demonstrate distribution of a 2850 MHz rf signal over stabilized optical fiber links. For a 2.2 km link they measure an rms drift of 19.4 fs over 60 h, and for a 200 m link an rms drift of 8.4 fs over 20 h. The rf signals are transmitted as amplitude modulation on a continuous optical carrier. Variations in the delay length are sensed using heterodyne interferometry and used to correct the rf phase. The system uses standard fiber telecommunications components.
Date: July 29, 2009
Creator: Wilcox, Russell B.; Byrd, J. M.; Doolittle, Lawrence; Huang, Gang & Staples, J. W.
Partner: UNT Libraries Government Documents Department
open access

Fabrication and Test of 90-mm Nb3Sn Quadrupole Model Based on Dipole-type Collar

Description: A series of 90-mm TQC quadrupole models with a collar-based mechanical structure has been fabricated and tested within the framework of the US-LHC Accelerator Research Program (LARP) using quadrupole-symmetric stainless steel collar laminations. This paper describes the design features, construction and test of TQC02Eb, the first TQC made with dipole-type collar and collaring techniques. Magnet test includes quench performance and field quality measurements at 4.5 and 1.9 K. Results of model pe… more
Date: July 29, 2010
Creator: Bossert, R.; Andreev, N.; Chlachidze, G.; Kashikhin, V. S.; Kashikhin, V. V.; Lamm, M. J. et al.
Partner: UNT Libraries Government Documents Department
open access

High Accuracy Wavelength Calibration For A Scanning Visible Spectrometer

Description: Spectroscopic applications for plasma velocity measurements often require wavelength accuracies ≤ 0.2Â. An automated calibration for a scanning spectrometer has been developed to achieve a high wavelength accuracy overr the visible spectrum, stable over time and environmental conditions, without the need to recalibrate after each grating movement. The method fits all relevant spectrometer paraameters using multiple calibration spectra. With a steping-motor controlled sine-drive, accuracies of ~… more
Date: July 29, 2010
Creator: Scotti, Filippo & Bell, Ronald
Partner: UNT Libraries Government Documents Department
open access

EARLY TESTS OF DRUM TYPE PACKAGINGS - THE LEWALLEN REPORT

Description: The need for robust packagings for radioactive materials (RAM) was recognized from the earliest days of the nuclear industry. The U.S. Department of Energy (DOE) Rocky Flats Plant developed a packaging for shipment of Pu in the early 1960's, which became the U.S. Department of Transportation (DOT) 6M specification package. The design concepts were employed in other early packagings. Extensive tests of these at Savannah River Laboratory (now Savannah River National Laboratory) were performed in … more
Date: July 29, 2010
Creator: Smith, A.
Partner: UNT Libraries Government Documents Department
open access

Certification of Superconducting Solenoid-Based Focusing Lenses

Description: The first production focusing lens for the HINS beam line at Fermilab has been assembled into a cryostat and tested. A total of 5 devices will be tested before they are installed in the low energy section of the HINS beam line, which uses copper Crossbar-H (CH) style RF cavities. One of the tested CH-section lens assemblies includes a pair of weak orthogonal steering dipoles nested within a strong focusing solenoid, and has six vapor cooled power leads. The other device has only the strong focu… more
Date: July 29, 2010
Creator: DiMarco, E.Joseph; Hemmati, Ali M.; Orris, Darryl F.; Page, Thomas M.; Rabehl, Roger H.; Tartaglia, Michael A. et al.
Partner: UNT Libraries Government Documents Department
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