Free-electron laser experiments in the microwave tokamak experiment (open access)

Free-electron laser experiments in the microwave tokamak experiment

Microwave pulses have been injected from a free electron-laser (FEL) into the Microwave Tokamak Experiment (MTX) at up to 0.2 GW at 140 GHz in short pulses (10-ns duration) with O-mode polarization. The power transmitted through the plasma was measured in a first experimental study of high power pulse propagation in the plasma; no nonlinear effects were found at this power level. Calculations indicate that nonlinear effects may be found at the higher power densities expected in future experiments. 9 refs., 2 figs.
Date: August 1, 1990
Creator: Allen, S. L.; Brown, M. D.; Byers, J. A.; Casper, T. A.; Cohen, B. I.; Cohen, R. H. et al.
System: The UNT Digital Library
A compute-ahead implementation of the fan-in sparse distributed factorization scheme (open access)

A compute-ahead implementation of the fan-in sparse distributed factorization scheme

In this report, we consider a compute-ahead computational technique in the distributed factorization of large sparse matrices using the fan-in parallel scheme. Experimental results on an Intel iPSC/2 hypercube are provided to demonstrate the relevance and effectiveness of this technique. Fortran source code is also included in an appendix. 9 refs., 2 figs., 1 tab.
Date: August 1, 1990
Creator: Ashcraft, C.; Eisenstat, S.C.; Sherman, A.H. (Yale Univ., New Haven, CT (USA). Dept. of Computer Science); Liu, J.W.H. (York Univ., Toronto, ON (Canada). Dept. of Computer Science) & Peyton, B.W. (Oak Ridge National Lab., TN (USA))
System: The UNT Digital Library
Development of a semi-automated workcell for repair of printed circuit boards (open access)

Development of a semi-automated workcell for repair of printed circuit boards

Printed circuit boards that comprise US Army electronic systems are repaired at Army depots. An existing automated diagnostic system determines the area of failure; either by identifying failed components or failed board traces. Currently, repairs are performed manually by trained technicians. A system is being developed for repair of through-hole printed circuit boards. It is comprised of many automated and operator-assisted functions to perform the multiple operations related to replacement of failed components. When completed, this system will demonstrate economic payback by reducing skilled labor requirements and decreasing rework. The semi-automated system integrates human operators into the process while maintaining high productivity. After several fully automated systems were conceived and modelled, it was found that the configuration that provided the best return on investment was comprised of a mix of autonomous and operator-assisted functions. 1 ref., 1 fig.
Date: August 1, 1990
Creator: Bennett, David W. & Evans, Mark S.
System: The UNT Digital Library
The high efficiency steel filters for nuclear air cleaning (open access)

The high efficiency steel filters for nuclear air cleaning

We have, in cooperation with industry, developed high-efficiency filters made from sintered stainless-steel fibers for use in several air-cleaning applications in the nuclear industry. These filters were developed to overcome the failure modes in present high-efficiency particulate air (HEPA) filters. HEPA filters are made from glass paper and glue, and they may fail when they get hot or wet and when they are overpressured. In developing our steel filters, we first evaluated the commercially available stainless-steel filter media made from sintered powder and sintered fiber. The sintered-fiber media performed much better than sintered-powder media, and the best media had the smallest fiber diameter. Using the best media, we then built prototype filters for venting compressed gases and evaluated them in our automated filter tester. 12 refs., 20 figs.
Date: August 1, 1990
Creator: Bergman, W.; Larsen, G.; Lopez, R.; Williams, K. & Violet, C.
System: The UNT Digital Library
High speed acquisition of multi-parameter data using a Macintosh II CX (open access)

High speed acquisition of multi-parameter data using a Macintosh II CX

Accelerator mass spectrometry systems based on >3MV tandem accelerators often use multi-anode ionization detectors and/or time-of-flight detectors to identify individual isotopes through multi-parameter analysis. A Macintosh llcx has been programmed to collect AMS data from a CAMAC-implemented analyzer and to display the histogrammed individual parameters and a double-parameter array. The computer-CAMAC connection is through a Nu-Bus to CAMAC dataway interface which allows direct addressing to all functions and locations in the crate. The asynchronous data from counting the rare isotope is sorted into a CAMAC memory module by a list sequence controller. Isotope switching is controlled by a one-cycle timing generator. A rate-dependent amount of time is used to transfer the data from the memory module at the end of each timing cycle. The present configuration uses 10 to 75 ms for rates of 500--10000 cps. Parameter analysis occurs during the rest of the 520 ms data collection cycle. Completed measurements of the isotope concentrations of each sample are written to files which are compatible with standard Macintosh databases or other processing programs. The system is inexpensive and operates at speeds comparable to those obtainable using larger computers.
Date: August 1, 1990
Creator: Berno, A.; Vogel, J.S. & Caffee, M.
System: The UNT Digital Library
New results from AGS (Alternating Gradient Synchrotron) heavy-ion experiments (open access)

New results from AGS (Alternating Gradient Synchrotron) heavy-ion experiments

We review the most recent data from Experiments 802, 810 and 814 of the heavy-ion program at the Brookhaven Alternating Gradient Synchrotron (AGS). 8 refs., 6 figs.
Date: August 1, 1990
Creator: Bloomer, M.A. (Lawrence Berkeley Lab., CA (USA)); Love, W. (Brookhaven National Lab., Upton, NY (USA)) & Waters, L. (State Univ. of New York, Stony Brook, NY (USA))
System: The UNT Digital Library
Integrating energy expertise into building design (open access)

Integrating energy expertise into building design

Most commercial buildings designed to today will use more energy to operate, and cost more to design and construct than necessary. Significant energy savings cold be achieved with little or not increase in first cost if energy-efficient design technologies were used. Research into integration of building systems indicates that by considering energy performance early in the design process, energy savings between 30% and 50% of current energy consumption rates are technically and economically feasible. However, most building design teams do not adequately consider the energy impacts of design decisions to achieve these savings. The US Department of Energy has initiated a project, led by Pacific Northwest Laboratory, to develop advanced computer-based technologies that will help designers take advantage of these large potential energy savings. The objective of this work is to develop automated, intelligent, energy design assistance that can be integrated into computer aided design systems of the future. This paper examines the need for this technology by identifying the impediments to energy-efficient design, identifies essential and desirable features of such systems, presents the concept under development in this effort, illustrates how energy expertise might be incorporated into design, and discusses the importance of an integrated approach. 8 refs., 1 …
Date: August 1990
Creator: Brambley, Michael R.; Stratton, Rex C. & Bailey, Mark L.
System: The UNT Digital Library
Uses of Fabry-Perot Velocimeters in Studies of High Explosives Detonation (open access)

Uses of Fabry-Perot Velocimeters in Studies of High Explosives Detonation

The Fabry Perot has become an important and valuable tool by which explosive performance information can be obtained relatively easily and inexpensively. Principle uses of the Fabry Perot have been free surface, and particle velocity measurements in one dimensional studies of explosive performance. In the cylinder test, it has been very useful to resolve early wall motions. We have refined methods of characterizing new explosives i.e. equation of state, C-J pressure, via the cylinder shot, flat plate, and particle velocity techniques. All of these use Fabry Perot as one of the principle diagnostics. Each of these experimental techniques are discussed briefly and some of the results obtained. Modeling developed to fit Fabry-Perot results are described along with future testing.
Date: August 27, 1990
Creator: Breithaupt, R. D. & Tarver, C. M.
System: The UNT Digital Library
Bound-state quark and gluon contributions to structure functions in QCD (open access)

Bound-state quark and gluon contributions to structure functions in QCD

One can distinguish two types of contributions to the quark and gluon structure functions of hadrons in quantum chromodynamics: intrinsic'' contributions, which are due to the direct scattering on the bound-state constituents, and extrinsic'' contributions, which are derived from particles created in the collision. In this talk, I discussed several aspects of deep inelastic structure functions in which the bound-state structure of the proton plays a crucial role: the properties of the intrinsic gluon distribution associated with the proton bound-state wavefunction; the separation of the quark structure function of the proton onto intrinsic bound-valence'' and extrinsic non-valence'' components which takes into account the Pauli principle; the properties and identification of intrinsic heavy quark structure functions; and a theory of shadowing and anti-shadowing of nuclear structure functions, directly related to quark-nucleon interactions and the gluon saturation phenomenon. 49 refs., 5 figs.
Date: August 1, 1990
Creator: Brodsky, Stanley J.
System: The UNT Digital Library
Conference summary: Quantum chromodynamics at small x (open access)

Conference summary: Quantum chromodynamics at small x

The range of electroproduction kinematics x{sub Bj} = Q{sup 2}/(2p {center dot} q) {ge} 10{sup {minus}4} at Q{sup 2} {ge} 10 GeV{sup 2} accessible at the HERA e {minus} p collider will provide a challenging high energy testing ground for quantum chromodynamics in a regime where the gluon distribution of the proton is expected to saturate and new types of multi-scattering higher twist contributions to structure functions become important. In this summary I give a brief overview of the recent theoretical work presented at the Hamburg conference. 19 refs., 2 figs.
Date: August 1, 1990
Creator: Brodsky, Stanley J.
System: The UNT Digital Library
Spin Matching Conditions in Large Electron Storage Rings with Purely Horizontal Beam Polarization. (open access)

Spin Matching Conditions in Large Electron Storage Rings with Purely Horizontal Beam Polarization.

None
Date: August 1, 1990
Creator: Burgess, Richard
System: The UNT Digital Library
The pad readout electronics of the SLD Warm Iron Calorimeter (open access)

The pad readout electronics of the SLD Warm Iron Calorimeter

The design of the pad readout electronics of the Warm Iron Calorimeter for the SLD detector at SLAC, consisting of about 9000 analog channels, is described. Results of various tests performed during the construction, installation and commissioning of the electronics mounted on the detector are presented. 10 refs., 12 figs.
Date: August 1, 1990
Creator: Burrows, P. N.; Busza, W.; Cartwright, S. L.; Friedman, J. I.; Fuess, S.; Gonzalez, S. et al.
System: The UNT Digital Library
Mild coal gasification screw pyrolyzer development and design (open access)

Mild coal gasification screw pyrolyzer development and design

Our objective is to produce information and design recommendations needed for the development of an efficient continuous process for the mild gasification of caking bituminous coals. We have focused on the development of an externally heated pyrolyzer in which the sticky, reacting coal is conveyed by one or more screws. We have taken a multifaceted approach to forwarding the development of the externally-heated screw pyrolyzer. Small scale process experiments on a 38-mm single screw pyrolyzer have been a major part of our effort. Engineering analyses aimed at producing design and scaleup equations have also been important. Process design recommendations follow from these. We critically review our experimental data and experience, and information from the literature and equipment manufactures for the purpose of making qualitative recommendations for improving practical pyrolyzer design and operation. Benchscale experiments are used to supply needed data and test some preliminary concepts. 6 refs., 4 figs., 1 tab.
Date: August 1, 1990
Creator: Camp, D.W.
System: The UNT Digital Library
Waste storage in the vadose zone affected by water vapor condensation and leaching (open access)

Waste storage in the vadose zone affected by water vapor condensation and leaching

One of the major concerns associated with waste storage in the vadose zone is that toxic materials may somehow be leached and transported by advecting water down to the water table and reach the accessible environment through either a well or discharge to a river. Consequently, care is taken to provide barriers over and around the storage sites to reduce contact between infiltrating water and the buried waste form. In some cases, it is important to consider the intrusion of water vapor as well as water in the liquid phase. Water vapor diffuses through porous material along vapor pressure gradients. A slightly low temperature, or the presence of water-soluble components in the waste, favors water condensation resulting in leaching of the waste form and advection of water-soluble components to the water table. A simple analysis is presented that allows one to estimate the rate of vapor condensation as a function of waste composition and backfill materials. An example using a waste form surrounded by concrete and gravel layers is presented. The use of thermal gradients to offset condensation effects of water-soluble components in the waste form is discussed. Thermal gradients may be controlled by design factors that alter the atmospheric …
Date: August 1, 1990
Creator: Cary, J. W.; Gee, G. W. & Whyatt, G. A.
System: The UNT Digital Library
Cumulative beam breakup of the ground-based-free-electron laser (open access)

Cumulative beam breakup of the ground-based-free-electron laser

Strategies employed by the Ground-Based Free Electron Laser system to maintain beam stability in its rf linac against cumulative beam breakup will be described. These strategies include a proper choice of cavity shape and the use of staggered tuning. Simulations show that the growths of effective transverse emittance due to cumulative beam breakup can be limited to 10%. 4 refs., 5 figs., 1 tab.
Date: August 7, 1990
Creator: Chan, K. C. D. & Spalek, G.
System: The UNT Digital Library
Measurement and Simulation of Whole Beam Brightness on the ETA-II (Experimental Test Accelerator-II) Linear Induction Accelerator (open access)

Measurement and Simulation of Whole Beam Brightness on the ETA-II (Experimental Test Accelerator-II) Linear Induction Accelerator

Measurement of beam radius as a function of focusing strength of an upstream solenoidal field allows simultaneous determination of the beam energy, brightness and tilt of the phase space ellipse. On ETA-II beam radius has been measured by analyzing foil emitted Cherenkov light with a gated (5 ns) image intensified CCD camera. The beam energy measurement is corroborated with a spectrometer magnet and core brightness with a two hole emittance diagnostic. For a 6 MeV, 1.6 kA beam, the whole beam brightness was measured to be 4.0 {times} 10{sup 8} A/(m-rad){sup 2} with an inner core (few percent) brightness of 1.2 {times} 10{sup 9} A/(m-rad){sup 2}. The data was simulated with a particle transport code that includes the effects of energy sweep and magnetic misalignment. The code predicts a halo produced by an orbital resonance that is also observed experimentally.
Date: August 7, 1990
Creator: Chen, Y. J.; CLark, J. C.; Paul, A. C.; Nexsen, W. E. & Turner, W. C.
System: The UNT Digital Library
Hadron spectroscopy at RHIC (open access)

Hadron spectroscopy at RHIC

A description is given of the physics opportunities at RHIC regarding quark-gluon spectroscopy. The basic idea is to isolate with appropriate triggers the subprocesses pomeron + pomeron {yields} hadrons and {gamma}* + {gamma}* {yields} hadrons with the net effective mass of hadrons in the range of 1.0 to 3.0 GeV, in order to study the hadronic states composed of u, d, and s and gluons. The double-pomeron interactions are expected to produce glueballs and hybrids preferentially, while the two-offshell-photon initial states should couple predominantly to quarkonia and multiquark states. A plethora of J{sup PC}-exotic mesons can be produced either directly in both types of interactions or in association with a single recoil photon in the final state. 8 refs., 2 figs.
Date: August 1, 1990
Creator: Chung, S. U.; Kern, W. & Willutzki, H. J.
System: The UNT Digital Library
Scattering by anisotropic grains in beryllium mirrors (open access)

Scattering by anisotropic grains in beryllium mirrors

Scattering from mirror surfaces arises from topographic and non-topographic sources. This paper considers the nontopographic scattering of beryllium mirrors modelled as a collection of randomly oriented bireflective grains. Simple scattering theory shows that this type of scatting scales as {lambda}{sup {minus}2}, rather than as {lambda}{sup {minus}4} for topographic scattering, which means that it is relatively more important at long radiation wavelengths. Estimates of the intensity based an available short-wavelength values of the anisotropic optical constants of beryllium indicate that this type of scattering could dominate the topographic scattering from smooth surfaces at CO{sub 2} wavelengths. 10 refs., 2 figs.
Date: August 1, 1990
Creator: Church, E.L. (Army Armament Research and Development Command, Dover, NJ (USA)); Takacs, P.Z. (Brookhaven National Lab., Upton, NY (USA)) & Stover, J.C. (TMA Technologies, Inc., Bozeman, MT (USA))
System: The UNT Digital Library
Search for the top quark and other new particles at p p colliders (open access)

Search for the top quark and other new particles at p p colliders

Results from searches for the top quark, supersymmetric particles, and new gauge bosons at the CERN and Fermilab proton-antiproton colliders are reviewed. 22 refs., 15 figs., 3 tabs.
Date: August 1990
Creator: Contreras, Milciades
System: The UNT Digital Library
Conservation voltage reduction potential in the Pacific Northwest (open access)

Conservation voltage reduction potential in the Pacific Northwest

This paper summarizes a study performed by Pacific Northwest Laboratory (PNL) indicating that the region-wide implementation of conservation voltage reduction (CVR) would provide a significant level of electric energy conservation in the Bonneville Power Administration (BPA) service area. This resource was estimated by developing supply curves showing the magnitude of energy savings as a function of CVR implementation cost. Energy savings were estimated for residential, commercial, agricultural irrigation, and industrial consumer classes. Using the convention of expressing energy conservation in average megawatts (AMW), the CVR conservation resource in the Pacific Northwest was estimated to be between 170 and 268 AMW at a cost of 5 cents/kWh. Estimates were also made for the contribution of major load sectors to the total CVR resource. Approximately 55% of the total was estimated to be available in the residential sector. Contributions by the other sectors considered were as follows: commercial, 29%; industrial, 14%; and agricultural irrigation, 3%. A large portion (142 to 230 AMW) of the conservation resource would be available at less than 1 cent/kWh. a median estimate of the regional CVR resource at 1 cent/kWh (179 AMW) exceeds the conservation potential (150 AMW) expected from possible implementation of major efficiency improvements on …
Date: August 1, 1990
Creator: De Steese, J. G.; Englin, J. E. & Sands, R. D.
System: The UNT Digital Library
Progress in ETA-II magnetic field alignment using stretched wire and low energy electron beam techniques (open access)

Progress in ETA-II magnetic field alignment using stretched wire and low energy electron beam techniques

Flux line alignment of the solenoidal focus magnets used on the ETA-II linear induction accelerator is a key element leading to a reduction of beam corkscrew motion. Two techniques have been used on the ETA-II accelerator to measure and establish magnet alignment. A low energy electron beam has been used to directly map magnetic field lines, and recent work has utilized a pulsed stretched wire technique to measure magnet tilts and offsets with respect to a reference axis. This paper reports on the techniques used in the ETA-II accelerator alignment, and presents results from those measurements which show that accelerator is magnetically aligned to within {approximately}{plus minus}200 microns. 3 refs., 8 figs.
Date: August 17, 1990
Creator: Deadrick, F. J. & Griffith, L. V.
System: The UNT Digital Library
CP asymmetries in B sup 0 decays beyond the Standard Model (open access)

CP asymmetries in B sup 0 decays beyond the Standard Model

Of the many ingredients of the Standard Model that are relevant for the analysis of CP asymmetries in B{sup 0} decays, some are likely to hold even beyond the Standard Model while other are sensitive to new physics. Consequently, certain predictions are maintained while other may shoe dramatic deviations from the Standard Model. Many classes of models may show clear signatures when the asymmetries are measured: four quark generations, Z-mediated flavor changing neutral currents, supersymmetry and real superweak'' models. On the other hand, models of left-right symmetry and multi-Higgs sectors with natural flavor conservation are unlikely to modify the Standard Model predictions.
Date: August 1, 1990
Creator: Dib, C.O. (California Univ., Los Angeles, CA (USA). Dept. of Physics); London, D. (Montreal Univ., PQ (Canada). Lab. de Physique Nucleaire) & Nir, Y. (Stanford Linear Accelerator Center, Menlo Park, CA (USA))
System: The UNT Digital Library
Antimatter, strangeness and exotic objects at RHIC (relativistic heavy ion collider) (open access)

Antimatter, strangeness and exotic objects at RHIC (relativistic heavy ion collider)

We investigate the production of multiply strange composite objects and their antiparticles in collisions at the relativistic heavy ion collider RHIC.
Date: August 1, 1990
Creator: Dover, C. B.
System: The UNT Digital Library
Stimulated Raman scatter from laser-produced plasmas: Merely nonlinear or also chaotic (open access)

Stimulated Raman scatter from laser-produced plasmas: Merely nonlinear or also chaotic

Stimulated Raman scattering in plasmas is a three-wave instability with important practical consequences for laser fusion. Most studies of this process to date have focused on its threshold. Even the linear-theory threshold poses interesting problems; and observed thresholds have been difficult to interpret. However, with increasing evidence that this instability often becomes absolute, it has become appropriate to examine saturation mechanisms as well. A number of such mechanisms are discussed here, one of which has been reported to have a chaotic regime. 26 refs., 4 figs.
Date: August 21, 1990
Creator: Drake, R. P. & Batha, S. H.
System: The UNT Digital Library