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Nature and effects of ion-cyclotron fluctuations in TMX

Description: In the tandem mirror experiment (TMX), coherent oscillations have been identified as resulting from the Alfven ion-cyclotron instability. Although the drive for this instability is localized in the end cell, the waves generated propagate out of the unstable region and interact with the central-cell ions. This interaction leads to an experimentally observed scaling of the stored end-cell energy with axial ion end-loss current.
Date: February 19, 1982
Creator: Casper, T. A.; Poulsen, P. & Smith, G. R.
Partner: UNT Libraries Government Documents Department
open access

Neutron capture studies: 1, Multiple capture reactions and implications for calculated beta-delayed fission rates: 2, The nuclear level structure of 238Np

Description: Astrophysical r-process calculations of transbismuth elements are of interest because certain actinide pairs can be treated as chronometers in determining the duration of nucleosynthesis. For one such calculation where a particularly long galactic age was derived, 21 + 2 - 4 Gyr, we present evidence that the effect of beta-delayed fission appears to be seriously overestimated in uranium decay chains with A = 252 to 257. With this conclusion, it follows that this estimate of the galactic age mus… more
Date: February 19, 1988
Creator: Hoff, R.W.
Partner: UNT Libraries Government Documents Department
open access

Beryllium Science: US-UK agreement on the use of Atomic Energy for mutual defense

Description: Twenty-seven papers are presented on beryllium supply, production, fabrication, safe handling, analysis, powder technology, and coatings. Separate abstracts have been prepared for the individual papers. (DLC)
Date: February 19, 1988
Creator: Hanafee, J.E. (ed.)
Partner: UNT Libraries Government Documents Department
open access

Correlation between predicted and observed levels of airborne tritium at Lawrence Livermore Laboratory site boundary

Description: At the Lawrence Livermore Laboratory, a computer code based on the Gaussian plume model is used to estimate radiation doses from routine or accidental release of airborne radioactive material. Routine releases of tritium have been used as a test of the overall uncertainty associated with these estimates. The ration of concentration to release rate at distances from the two principal release points to each of six site boundary sampling locations has been calcuated using local meteorological data… more
Date: February 19, 1980
Creator: Lindeken, C. L.; Silver, W. J.; Toy, A. J. & White, J. H.
Partner: UNT Libraries Government Documents Department
open access

ELLIPTIC FLOW, INITIAL ECCENTRICITY AND ELLIPTIC FLOW FLUCTUATIONS IN HEAVY ION COLLISIONS AT RHIC.

Description: We present measurements of elliptic flow and event-by-event fluctuations established by the PHOBOS experiment. Elliptic flow scaled by participant eccentricity is found to be similar for both systems when collisions with the same number of participants or the same particle area density are compared. The agreement of elliptic flow between Au+Au and Cu+Cu collisions provides evidence that the matter is created in the initial stage of relativistic heavy ion collisions with transverse granularity s… more
Date: February 19, 2007
Creator: Nouicer, R.; Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M. & Barton, D. S.
Partner: UNT Libraries Government Documents Department
open access

Weak interactions and presupernova evolution

Description: The role of weak interactions, particularly electron capture and {beta}{sup {minus}} decay, in presupernova evolution is discussed. The present uncertainty in these rates is examined and the possibility of improving the situation is addressed. 12 refs., 4 figs.
Date: February 19, 1991
Creator: Aufderheide, M.B. (Lawrence Livermore National Lab., CA (USA) State Univ. of New York (USA). Dept. of Physics)
Partner: UNT Libraries Government Documents Department
open access

Simple, compact, high brightness source for x-ray lithography and x-ray radiography

Description: A simple, compact, high brightness x-ray source has recently been built. This source utilizes a commercially available, cylindrical geometry electron beam evaporator, which has been modified to enhance the thermal cooling to the anode. Cooling is accomplished by using standard, low-conductivity laboratory water, with an inlet pressure of less than 50 psi, and a flow rate of approx.0.3 gal/min. The anode is an inverted cone geometry for efficient cooling. The x-ray source has a measured sub-mill… more
Date: February 19, 1986
Creator: Hawryluk, A.M.
Partner: UNT Libraries Government Documents Department
open access

Electrofibrous prefilters for use in nuclear ventilation systems

Description: We have established a comprehensive program for the US Department of Energy to develop electrofibrous prefilters to extend the life of High Efficiency Particulate Air (HEPA) filters that are used in the nuclear industry. We have selected the electrofibrous filter because, compared to the mechanical fibrous filter, it has a higher efficiency and longer lifetime. Two different electrofibrous filters have been developed for use in nuclear ventilation systems. One prototype is a stationary prefilte… more
Date: February 19, 1981
Creator: Bergman, W.; Kuhl, W. D.; Russell, W. L.; Taylor, R. D.; Hebard, H. D.; Biermann, A. H. et al.
Partner: UNT Libraries Government Documents Department
open access

Effects of the Electron Energy Distribution Function on Modeled X-ray Spectra

Description: This paper presents the results of a broad investigation into the effects of the electron energy distribution function on the predictions of non-LTE collisional-radiative atomic kinetics models. The effects of non-Maxwellian and suprathermal (''hot'') electron distributions on collisional rates (including three-body recombination) are studied. It is shown that most collisional rates are fairly insensitive to the functional form and characteristic energy of the electron distribution function as … more
Date: February 19, 2004
Creator: Shlyaptseva, A S & Hansen, S B
Partner: UNT Libraries Government Documents Department
open access

A finite Zitterbewegung model for relativistic quantum mechanics

Description: Starting from steps of length h/mc and time intervals h/mc{sup 2}, which imply a quasi-local Zitterbewegung with velocity steps {plus minus}c, we employ discrimination between bit-strings of finite length to construct a necessary 3+1 dimensional event-space for relativistic quantum mechanics. By using the combinatorial hierarchy to label the strings, we provide a successful start on constructing the coupling constants and mass ratios implied by the scheme. Agreement with experiments is surprisi… more
Date: February 19, 1990
Creator: Noyes, H. P.
Partner: UNT Libraries Government Documents Department
open access

Functional autonomy of distant-acting human enhancers

Description: Many human genes are associated with dispersed arrays of transcriptional enhancers that regulate their expression in time and space. Studies in invertebrate model systems have suggested that these elements function as discrete and independent regulatory units, but the in vivo combinatorial properties of vertebrate enhancers remain poorly understood. To explore the modularity and regulatory autonomy of human developmental enhancers, we experimentally concatenated up to four enhancers from differ… more
Date: February 19, 2009
Creator: Visel, Axel; Akiyama, Jennifer A.; Shoukry, Malak; Afzal, Veena; Rubin, Edward M. & Pennacchio, Len A.
Partner: UNT Libraries Government Documents Department
open access

Mechanical Design of the NSTX Liquid Lithium Divertor

Description: The Liquid Lithium Divertor (LLD) on NSTX will be the first test of a fully-toroidal liquid lithium divertor in a high-power magnetic confinement device. It will replace part of the lower outboard divertor between a specified inside and outside radius, and ultimately provide a lithium surface exposed to the plasma with enough depth to absorb a significant particle flux. There are numerous technical challenges involved in the design. The lithium layer must be as thin as possible, and maintained … more
Date: February 19, 2009
Creator: R. Ellis, R. Kaita, H. Kugel, G. Paluzzi, M. Viola and R. Nygren
Partner: UNT Libraries Government Documents Department
open access

Electroweak Symmetry Breaking via UV Insensitive Anomaly Mediation

Description: Anomaly mediation solves the supersymmetric flavor and CP problems. This is because the superconformal anomaly dictates that supersymmetry breaking is transmitted through nearly flavor-blind infrared physics that is highly predictive and UV insensitive. Slepton mass squareds, however, are predicted to be negative. This can be solved by adding D-terms for U(1)_Y and U(1)_{B-L} while retaining the UV insensitivity. In this paper we consider electroweak symmetry breaking via UV insensitive anomaly… more
Date: February 19, 2004
Creator: Kitano, Ryuichiro; Kribs, Graham D. & Murayama, Hitoshi
Partner: UNT Libraries Government Documents Department
open access

Low Distortion Welded Joints for NCSX

Description: The National Compact Stellarator Experiment (NCSX) required precise positioning of the field coils in order to generate suitable magnetic fields. A set of three modular field coils were assembled to form the Half Field-Period Assemblies (HPA). Final assembly of the HPA required a welded shear plate to join individual coils in the nose region due to the geometric limitations and the strength constraints. Each of the modular coil windings was wound on a stainless steel alloy (Stellalloy) casting.… more
Date: February 19, 2009
Creator: M. Denault, M Viola, W. England
Partner: UNT Libraries Government Documents Department
open access

Low Dose Radiation-Induced Genome and Epigenome Instability Symposium and Epigenetic Mechanisms, DNA Repair, and Chromatin Symposium at the EMS 2008 Annual Meeting - October 2008

Description: The Low Dose Radiation Symposium thoughtfully addressed ionizing radiation non-mutational but transmissable alterations in surviving cells. Deregulation of epigenetic processes has been strongly implicated in carcinogenesis, and there is increasing realization that a significant fraction of non-targeted and adaptive mechanisms in response to ionizing radiation are likely to be epigenetic in nature. Much remains to be learned about how chromatin and epigenetic regulators affect responses to low … more
Date: February 19, 2010
Creator: Morgan, William F.; Kovalchuk, Olga; Dolinoy, Dana C.; Dubrova, Yuri E.; Coleman, Matthew A.; Schär, Primo et al.
Partner: UNT Libraries Government Documents Department
open access

Lessons from Two Years of Building Fusion Ignition Targets with the Precision Robotic Assembly Machine

Description: The Precision Robotic Assembly Machine was developed to manufacture the small and intricate laser-driven fusion ignition targets that are being used in the world's largest and most energetic laser, the National Ignition Facility (NIF). The National Ignition Campaign (NIC) goal of using the NIF to produce a self-sustaining nuclear fusion burn with energy gain - for the first time ever in a laboratory setting - requires targets that are demanding in materials fabrication, machining, and assembly.… more
Date: February 19, 2010
Creator: Montesanti, R C; Alger, E T; Atherton, L J; Bhandarkar, S D; Castro, C; Dzenitis, E G et al.
Partner: UNT Libraries Government Documents Department
open access

Transport Properties for Combustion Modeling

Description: This review examines current approximations and approaches that underlie the evaluation of transport properties for combustion modeling applications. Discussed in the review are: the intermolecular potential and its descriptive molecular parameters; various approaches to evaluating collision integrals; supporting data required for the evaluation of transport properties; commonly used computer programs for predicting transport properties; the quality of experimental measurements and their import… more
Date: February 19, 2010
Creator: Brown, N. J.; Bastein, L. & Price, P. N.
Partner: UNT Libraries Government Documents Department
open access

Quantification of thin film crystallographic orientation using X-ray diffraction with an area detector

Description: As thin films become increasingly popular (for solar cells, LEDs, microelectronics, batteries), quantitative morphological information is needed to predict and optimize the film's electronic, optical and mechanical properties. This quantification can be obtained quickly and easily with X-ray diffraction using an area detector and synchrotron radiation in two simple geometries. In this paper, we describe a methodology for constructing complete pole figures for thin films with fiber texture (iso… more
Date: February 19, 2010
Creator: Baker, Jessica L; Jimison, Leslie H; Mannsfeld, Stefan; Volkman, Steven; Yin, Shong; Subramanian, Vivek et al.
Partner: UNT Libraries Government Documents Department
open access

Electron proton two-stream instability at the PSR.

Description: A strong, fast, transverse instability has long been observed at the Los Alamos Proton Storage Ring (PSR) where it is a limiting factor on peak intensity. Most of the available evidence, based on measurements of the unstable proton beam motion, is consistent with an electron-proton two-stream instability. The need for higher beam intensity at PSR [1] and for future high-intensity, proton drivers has motivated a multi-lab collaboration (LANL, ANL, FNAL, LBNL, BNL, ORNL, and PPPL) to coordinate r… more
Date: February 19, 2002
Creator: Macek, R. J.; Browman, A.; Fitzgerald, D.; McCrady, R.; Merrill, F.; Plum, M. et al.
Partner: UNT Libraries Government Documents Department
open access

Effects of lattice disorder in the UCu(5-x)Pd(x) system

Description: The UCu5-x Pdx system exhibits non-Fermi liquid (NFL) behavior in thermodynamic and transport properties at low temperatures for Pd concentrations 0.9 less than or approximately x less than or approximately 1.5. The local structure around the U, Cu, and Pd atoms has been measured for
Date: February 19, 2002
Creator: Bauer, E. D.; Booth, C. H.; Kwei, G. H.; Chau, R. & Maple, M. B.
Partner: UNT Libraries Government Documents Department
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