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Beryllium usage in fusion blankets and beryllium data needs. [None] (open access)

Beryllium usage in fusion blankets and beryllium data needs. [None]

Increasing numbers of designers are choosing beryllium for fusion reactor blankets because it, among all nonfissile materials, produces the highest number (2.5 neutron in an infinite media) of neutrons per 14-MeV incident neutron. In amounts of about 20 cm of equivalent solid density, it can be used to produce fissile material, to breed all the tritium consumed in ITER from outboard blankets only, and in designs to produce Co-60. The problem is that predictions of neutron multiplication in beryllium are off by some 10 to 20% and appear to be on the high side, which means that better multiplication measurements and numerical methods are needed. The n,2n reactions result in two helium atoms, which cause radiation damage in the form of hardening at low temperatures (<300/degree/C) and swelling at high temperatures (>300/degree/C). The usual way beryllium parts are made is by hot pressing the powder. A lower cost method is to cold press and then sinter. There is no radiation damage data on this form of beryllium. The issues of corrosion, safety relative to the release of the tritium built-up inside beryllium, and recycle of used beryllium are also discussed. 10 figs.
Date: April 6, 1988
Creator: Moir, Ralph W.
System: The UNT Digital Library
Sources of hot electrons in laser-plasma interaction with emphasis on Raman and turbulence absorption (open access)

Sources of hot electrons in laser-plasma interaction with emphasis on Raman and turbulence absorption

Heating targets with high power lasers results in a sizable fraction of the absorbed energy going into electrons of temperature much greater than thermal which can pre-heat the pellet core and accelerate fast ion blowoff which results in poor momentum transfer and hence poor compression efficiency. The present emphasis is to build lasers of higher frequency, ..omega../sub 0/, which at the same W/cm/sup 2/ results in more absorption into cooler electrons. Two physical reasons are that the laser can propagate to a higher electron density, n, infinity..omega../sub 0//sup 2/ resulting in more collisional inverse bremsstrahlung absorption proportional to n, and because the hot temperatures from some plasma absorption processes increase as the oscillatory velocity of an electron in the laser electric field v/sub 0//c = eE/(m/sub e/..omega../sub 0/). The heated electron temperatures from other plasma processes (Raman for example approx.(m/sub e//2)v/sup 2//sub phase/ and the higher laser frequency helps by increasing the competing collisional absorption and decreasing the Raman gain.
Date: April 6, 1982
Creator: Estabrook, K.; Kruer, W. L.; Phillion, D. W.; Turner, R. E. & Campbell, E. M.
System: The UNT Digital Library
Workshop on core and sample curation for the National Continental Scientific Drilling Program (open access)

Workshop on core and sample curation for the National Continental Scientific Drilling Program

The Workshop on Core and Sample Curation was held to discuss the best means of handling, distributing, and advertising samples and data collected during a Continental Scientific Drilling Program (CSDP) and to establish better communication between sample curators regarding common problems. It was geneerally agreed that CSDP samples should be handled, on a regional basis, by existing data systems and sample repositories judged to have adequate staff and support. Repository design, sample handling procedures, and sample accounting systems were discussed. Across North America, support for curation of geological samples was varied, but it was strongest within states or regions with well-established energy and mineral industries. A well-supported repository pays for itself through the circulation and preservation of samples and stratigraphic information. A national CSDP must have a well-established curatorial policy and system of regional repositories to circulate information and samples throughout the scientific community. Well-curated samples and data are a national resource with considerable benefits for industry and academia. Attendees agreed to form a Society of Geoscience Curators to maintain communication between curators from private, government, and university repositories and core research laboratories.
Date: May 6, 1981
Creator: Goff, S. & Heiken, G. (eds.)
System: The UNT Digital Library
Nuclear reaction uncertainties in standard and non-standard cosmologies (open access)

Nuclear reaction uncertainties in standard and non-standard cosmologies

We discuss here the uncertainties in the nuclear input data relevant for calculations of standard and non-standard primordial nucleosynthesis. We show how these uncertainties can affect the predictive power of such calculations, and we identify those key nuclear reactions for which improved experimental data on the associated reaction rates is most needed. Such experimental data can lead to more accurate discriminatory tests between the differing primordial nucleosynthesis scenarios. 34 refs., 3 tabs.
Date: October 6, 1989
Creator: Malaney, R.A.
System: The UNT Digital Library
Harmonically excited orbital variations (open access)

Harmonically excited orbital variations

Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs.
Date: August 6, 1985
Creator: Morgan, T.
System: The UNT Digital Library
Proceedings of the Conference on technology-based confidence building: Energy and environment (open access)

Proceedings of the Conference on technology-based confidence building: Energy and environment

This document contains excerpts from the proceedings of the conference on Technology-based Confidence Building: Energy and the Environment.'' It contains the agenda for the conference and a document on Global Warming and Energy Use;'' a presentation on from Militarism to Environmentalism: a New Focus of US-Soviet Relations;'' a workshop on environmental challenges; a summary address on Science, Technology, and World Affairs;'' an address entitled Energy: the Coin of International Understanding;'' and concluding remarks.
Date: November 6, 1989
Creator: unknown
System: The UNT Digital Library
Beam-storage studies in the Fermilab main ring (open access)

Beam-storage studies in the Fermilab main ring

Bunched beams of 100 and 150 GeV have been stored in the Fermilab Main Ring for periods of up to one hour. The observations of beam current and beam profiles are analyzed for the effects of gas scattering, chromaticity and non-linear magnetic field.
Date: May 6, 1982
Creator: MacLachlan, J.A.
System: The UNT Digital Library
Small power plant reverse trade mission (open access)

Small power plant reverse trade mission

This draft report was prepared as required by Task No. 2 of the US Department of Energy, Grant No. FG07-89ID12850 Reverse Trade Mission to Acquaint International Representatives with US Power Plant and Drilling Technology'' (mission). As described in the grant proposal, this report covers the reactions of attendees toward US technology, its possible use in their countries, and an evaluation of the mission by the staff leaders. Note this is the draft report of one of two missions carried out under the same contract number. Because of the diversity of the mission subjects and the different attendees at each, a separate report for each mission has been prepared. This draft report has been sent to all mission attendees, specific persons in the US Department of Energy and Los Alamos National Lab., the California Energy Commission (CEC), and various other governmental agencies.
Date: September 6, 1989
Creator: unknown
System: The UNT Digital Library
BWR containment failure analysis during degraded-core accidents (open access)

BWR containment failure analysis during degraded-core accidents

This paper presents a containment failure mode analysis during a spectrum of postulated degraded core accident sequences in a typical 1000-MW(e) boiling water reactor (BWR) with a Mark-I wetwell containment. Overtemperature failure of containment electric penetration assemblies (CEPAs) has been found to be the major failure mode during such accidents.
Date: June 6, 1982
Creator: Yue, D.D.
System: The UNT Digital Library
Comparisons of hydrodynamic beam models with kinetic treatments (open access)

Comparisons of hydrodynamic beam models with kinetic treatments

Hydrodynamic models have been derived by Mark and Yu and by others to describe energetic self-pinched beams, such as those used in ion-beam fusion. The closure of the Mark-Yu model is obtained with adiabatic assumptions mathematically analogous to those of Chew, Goldberger, and Low for MHD. The other models treated here use an ideal gas closure and a closure by Newcomb based on an expansion in V/sub th//V/sub z/. Features of these hydrodynamic beam models are compared with a kinetic treatment.
Date: October 6, 1983
Creator: Boyd, J. K.; Mark, J. W.; Sharp, W. M. & Yu, S. S.
System: The UNT Digital Library
Present development status of Exxon's zinc-bromine battery for bulk energy storage (open access)

Present development status of Exxon's zinc-bromine battery for bulk energy storage

Diagrams and slide reproductions of the system are presented; and performance, maintenance, and cost information is outlined. (WHK)
Date: May 6, 1982
Creator: Bellows, R. & Malachesky, P.
System: The UNT Digital Library
Programmable controller with overcurrent latch for constant primary peak current in capacitor-charging FET switcher for Nova (open access)

Programmable controller with overcurrent latch for constant primary peak current in capacitor-charging FET switcher for Nova

New switching power supplies were designed for the 10 mm laser amplifiers in the Nova Master Oscillator Room. The flashlamp supply must be repratable. Therefore, we designed a constant current, linearly charging power supply. Since it is a capacitor, the load varies throughout the charge cycle. At first the load is great, and di/dt of load current is at a maximum. As the capacitor charges the initial conditions for each cycle change, the power supply in effect sees a smaller capacitance, and di/dt decreases. We need a way of gradually increasing the on-time of the current pulses so that the transistors in the power bridge are turned off when they reach their maximum peak current. The normal current sense response of the control chip is not fast enough to be useful for our application. The deadtime, or the time that all the bridge transistors are turned off, is fixed so that as the pulse width varies so does the period. We end up with a constant peak current, switching power supply whose frequency varies from 50 khz to 20 khz. Finally, an overcurrent latch protects the transistors from bridge or transformer faults. The circuit is described and results are shown.
Date: June 6, 1983
Creator: Mihalka, A. M.
System: The UNT Digital Library
Structured Assessment Approach: a procedure for the assessment of fuel cycle safeguard systems (open access)

Structured Assessment Approach: a procedure for the assessment of fuel cycle safeguard systems

Lawrence Livermore National Laboratory has developed and tested for the United States Nuclear Regulatory Commission a procedure for the evaluation of Material Control and Accounting (MC and A) Systems at Nuclear Fuel Facilities. This procedure, called the Structured Assessment Approach, SAA, subjects the MC and A system at a facility to a series of increasingly sophisticated adversaries and strategies. A fully integrated version of the computer codes which assist the analyst in this assessment was made available in October, 1979. The concepts of the SAA and the results of the assessment of a hypothetical but typical facility are presented.
Date: March 6, 1980
Creator: Parziale, A.A.; Patenaude, C.J.; Renard, P.A. & Sacks, I.J.
System: The UNT Digital Library
Modeling ferrite electromagnetic response in the time domain (open access)

Modeling ferrite electromagnetic response in the time domain

The behavior of ferrite loads commonly found in induction accelertors has important consequences for the performance of these accelerators. Previous work by the authors on modeling the electromagnetic fields in induction cavities has focussed upon use of a simple, phenomenological model for the process of magnetization reversal in these ferrite loads. In this paper we consider a model for magnetization reversal which is more deeply rooted in theory, and present a simulation of the reversal process based upon this model for an idealized set of boundary conditions. 7 refs., 3 figs.
Date: April 6, 1989
Creator: Johnson, J.; DeFord, J. F. & Craig, G. D.
System: The UNT Digital Library
A site oriented supercomputer for theoretical physics: The Fermilab Advanced Computer Program Multi Array Processor System (ACMAPS) (open access)

A site oriented supercomputer for theoretical physics: The Fermilab Advanced Computer Program Multi Array Processor System (ACMAPS)

The ACPMAPS multipocessor is a highly cost effective, local memory parallel computer with a hypercube or compound hypercube architecture. Communication requires the attention of only the two communicating nodes. The design is aimed at floating point intensive, grid like problems, particularly those with extreme computing requirements. The processing nodes of the system are single board array processors, each with a peak power of 20 Mflops, supported by 8 Mbytes of data and 2 Mbytes of instruction memory. The system currently being assembled has a peak power of 5 Gflops. The nodes are based on the Weitek XL Chip set. The system delivers performance at approximately $300/Mflop. 8 refs., 4 figs.
Date: March 6, 1989
Creator: Nash, T.; Atac, R.; Cook, A.; Deppe, J.; Fischler, M.; Gaines, I. et al.
System: The UNT Digital Library
X-ray microscopy using grazing-incidence reflection optics (open access)

X-ray microscopy using grazing-incidence reflection optics

The Kirkpatrick-Baez microscopes are described along with their role as the workhorse of the x-ray imaging devices. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics.
Date: August 6, 1981
Creator: Price, R.H.
System: The UNT Digital Library
Database tools for enhanced analysis of TMX-U data (open access)

Database tools for enhanced analysis of TMX-U data

A commercial database software package has been used to create several databases and tools that assist and enhance the ability of experimental physicists to analyze data from the Tandem Mirror Experiment-Upgrade (TMX-U) experiment. This software runs on a DEC-20 computer in M-Division's User Service Center at Lawrence Livermore National Laboratory (LLNL), where data can be analyzed offline from the main TMX-U acquisition computers. When combined with interactive data analysis programs, these tools provide the capability to do batch-style processing or interactive data analysis on the computers in the USC or the supercomputers of the National Magnetic Fusion Energy Computer Center (NMFECC) in addition to the normal processing done by the TMX-U acquisition system. One database tool provides highly reduced data for searching and correlation analysis of several diagnostic signals within a single shot or over many shots. A second database tool provides retrieval and storage of unreduced data for use in detailed analysis of one or more diagnostic signals. We will show how these database tools form the core of an evolving offline data analysis environment on the USC computers.
Date: March 6, 1986
Creator: Stewart, M. E.; Carter, M. R.; Casper, T. A.; Meyer, W. H.; Perkins, D. E. & Whitney, D. M.
System: The UNT Digital Library
Measurements of magnetic field alignment (open access)

Measurements of magnetic field alignment

The procedure for installing Superconducting Super Collider (SSC) dipoles in their respective cryostats involves aligning the average direction of their field with the vertical to an accuracy of 0.5 mrad. The equipment developed for carrying on these measurements is described and the measurements performed on the first few prototypes SSC magnets are presented. The field angle as a function of position in these 16.6 m long magnets is a characteristic of the individual magnet with possible feedback information to its manufacturing procedure. A comparison of this vertical alignment characteristic with a magnetic field intensity (by NMR) characteristic for one of the prototypes is also presented. 5 refs., 7 figs.
Date: November 6, 1987
Creator: Kuchnir, M. & Schmidt, E.E.
System: The UNT Digital Library
Computer representation of molecular surfaces (open access)

Computer representation of molecular surfaces

This review article surveys recent work on computer representation of molecular surfaces. Several different algorithms are discussed for producing vector or raster drawings of space-filling models formed as the union of spheres. Other smoother surfaces are also considered.
Date: July 6, 1981
Creator: Max, N.L.
System: The UNT Digital Library
Analytical cytology applied to detection of induced cytogenetic abnormalities (open access)

Analytical cytology applied to detection of induced cytogenetic abnormalities

Radiation-induced biological damage results in formation of a broad spectrum of cytogenetic changes such as translocations, dicentrics, ring chromosomes, and acentric fragments. A battery of analytical cytologic techniques are now emerging that promise to significantly improve the precision and ease with which these radiation induced cytogenetic changes can be quantified. This report summarizes techniques to facilitate analysis of the frequency of occurrence of structural and numerical aberrations in control and irradiated human cells. 14 refs., 2 figs.
Date: August 6, 1987
Creator: Gray, J.W.; Lucas, J.; Straume, T. & Pinkel, D.
System: The UNT Digital Library
Microhardness Tests for High-Energy Neutron-Source Experiments (open access)

Microhardness Tests for High-Energy Neutron-Source Experiments

In a development effort to extract mechanical property information from miniature specimens, standard diamond pyramid microhardness (DPH) tests have been conducted at Hanford Engineering Development Laboratory (HEDL) on specimens irradiated in RTNS-II; and techniques to extend the information available from microhardness tests have been developed at the University of California, Santa Barbara (UCSB). In tests at HEDL, radiation hardening has only been observed in relatively pure materials irradiated to neutron fluences less than 4 x 10/sup 17/ n/cm/sup 2/. In copper, specifically, a proportional increase in the DPH with neutron fluence has been observed, and this microhardness increase has been correlated with an increase in the 0.2 percent offset yield strength. At UCSB it has been found that hardness and microhardness data obtained with spherical indenters can be used to determine the true stress-true plastic strain relationship of the test material; moreover, it has been found that features of the indentation lip geometry can be used to characterize localized flow phenomena like Lueders strain in steel. Consequently, microhardness test techniques appear attractive for small specimen test applications.
Date: August 6, 1981
Creator: Panayotou, N. F. & Lucas, G. E.
System: The UNT Digital Library
Alternating gradient synchrotron (open access)

Alternating gradient synchrotron

With the start of a research and development effort directed towards the Superconducting Super Collider (SSC), it is essential that US industry become involved as soon as possible. For that reason, I describe what a conventional accelerator complex is like and therefore what the first stages of the SSC would entail.
Date: December 6, 1984
Creator: Lowenstein, D.I.
System: The UNT Digital Library
Database tools for enhanced analysis of TMX-U data. Revision 1 (open access)

Database tools for enhanced analysis of TMX-U data. Revision 1

A commercial database software package has been used to create several databases and tools that assist and enhance the ability of experimental physicists to analyze data from the Tandem Mirror Experiment-Upgrade (TMX-U) experiment. This software runs on a DEC-20 computer in M-Division's User Service Center at Lawrence Livermore National Laboratory (LLNL), where data can be analyzed offline from the main TMX-U acquisition computers. When combined with interactive data analysis programs, these tools provide the capability to do batch-style processing or interactive data analysis on the computers in the USC or the supercomputers of the National Magnetic Fusion Energy Computer Center (NMFECC) in addition to the normal processing done by the TMX-U acquisition system. One database tool provides highly reduced data for searching and correlation analysis of several diagnostic signals within a single shot or over many shots. A second database tool provides retrieval and storage of unreduced data for use in detailed analysis of one or more diagnostic signals. We will show how these database tools form the core of an evolving offline data analysis environment on the USC computers.
Date: March 6, 1986
Creator: Stewart, M. E.; Carter, M. R.; Casper, T. A.; Meyer, W. H.; Perkins, D. E. & Whitney, D. M.
System: The UNT Digital Library
Relativity: X-ray and auger transitions of highly charged ions (open access)

Relativity: X-ray and auger transitions of highly charged ions

Many-electron QED correction is one of the unsolved problems in relativistic atomic structure calculations for many-electron systems. The accuracy of the effective-charged screening approach frequently used in the MCDF model to estimate the many-electron QED corrections is examined. The effects of relativity and configuration interaction are simultaneously important in the treatment of highly-charged ions. These effects can sometimes change the transition rates by orders of magnitude; numerous irregularities present in Auger rates and oscillator strengths along the isoelectronic sequence due to the level crossings. The spin-orbit mixing and Breit interaction are responsible for the decay of most of the high-spin metastable autoionizing states. 29 refs., 8 figs.
Date: March 6, 1989
Creator: Chen, Mau Hsiung
System: The UNT Digital Library