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Hydrodynamics of post CHF region (open access)

Hydrodynamics of post CHF region

Among various two-phase flow regimes, the inverted flow in the post-dryout region is relatively less well understood due to its special heat transfer conditions. The review of existing data indicates further research is needed in the areas of basic hydrodynamics related to liquid core disintegration mechanisms, slug and droplet formations, entrainment, and droplet size distributions. In view of this, the inverted flow is studied in detail both analytically and experimentally. Criteria for initial flow regimes in the post-dryout region are given. Preliminary models for subsequent flow regime transition criteria are derived together with correlations for a mean droplet diameter based on the adiabatic simulation data.
Date: April 1, 1984
Creator: Ishii, M. & De Jarlais, G.
System: The UNT Digital Library
Rare muon decays and lepton-family number conservation (open access)

Rare muon decays and lepton-family number conservation

A brief historical survey of the discovery of the muon, interest in neutrinoless processes, and lepton-number conservation laws is given. The present view of lepton-number conservation laws and the search for ..mu.. ..-->.. e..gamma.. are described. Other experiments are discussed including ..mu../sup +/ ..-->.. e/sup +/e/sup +/e/sup -/ decay, ..mu../sup -/Z ..-->.. e/sup -/Z reactions, ..mu.. ..-->.. e ..gamma gamma.. decay, other rare muon processes, strangeness-changing muon-number-nonconserving decays, and tau decays. 52 references. (WHK)
Date: April 1, 1984
Creator: Hoffman, C. M.
System: The UNT Digital Library
New particles and interactions (open access)

New particles and interactions

The Working Group on New Particles and Interactions met as a whole at the beginning and at the end of the Workshop. However, much of what was accomplished was done in five subgroups. These were devoted to: (1) new quarks and leptons; (2) technicolor; (3) supersymmetry; (4) rare decays and CP; and (5) substructure of quarks and leptons. Other aspects of new particles, e.g., Higgs, W', Z', fell to the Electroweak Working Group to consider. The central question of this Workshop of comparing anti pp (with L = 10/sup 32//cm/sup 2/-sec) with pp (with L = 10/sup 33//cm/sup 2/-sec) colliders carried through to all these subgroups. In addition there were several other aspects of hadron colliders which were considered: what does an increase in ..sqrt..s gain in cross section and resultant sensitivity to new physics versus an increase in luminosity; will polarized beams or the use of asymmetries be essential in finding new interactions; where and at what level do rate limitations due to triggering or detection systems play a role; and how and where will the detection of particles with short, but detectable, lifetimes be important. 25 references.
Date: April 1, 1984
Creator: Gilman, F. J. & Grannis, P. D.
System: The UNT Digital Library
Resonance ionization spectroscopy of argon, krypton, and xenon using vacuum ultraviolet light (open access)

Resonance ionization spectroscopy of argon, krypton, and xenon using vacuum ultraviolet light

Resonant, single-photon excitation of ground state inert gases requires light in the vacuum ultraviolet spectral region. This paper discusses methods for generating this light. Efficient schemes for ionizing argon, krypton, and xenon using resonant, stepwise single-photon excitation are presented.
Date: April 1, 1984
Creator: Kramer, S. D.
System: The UNT Digital Library
RFQ radial matching sections and fringe fields (open access)

RFQ radial matching sections and fringe fields

The entrance radial matching section is an extremely important part of any radio-frequency quadrupole (RFQ) linac. It allows a beam having time-independent characteristics to become adapted to the time-dependent focusing in the RFQ. The matching sections proposed in this paper are defined by a four-term potential function and are very effective over lengths of 3 ..beta.. lambda or longer. The fringe field at the RFQ exit is mainly of interest because of the time-varying on-axis potential. The beam can either lose or gain energy, depending on the shape of the fringe field. The same four-term potential function can be used for shaping the vanes at the exit so that the fringe fields can be controlled. This formulation also applies to exit radial matching sections, which would be useful if the beam is to enter another RFQ operated at a higher frequency. 4 references, 4 figures.
Date: April 1, 1984
Creator: Crandall, K. R.
System: The UNT Digital Library
Accelerator-based atomic physics experiments with photon and ion beams (open access)

Accelerator-based atomic physics experiments with photon and ion beams

Accelerator-based atomic physics experiments at Brookhaven presently use heavy-ion beams from the Dual MP Tandem Van de Graaff Accelerator Facility for atomic physics experiments of several types. Work is presently in progress to develop experiments which will use the intense photon beams which will be available in the near future from the ultraviolet (uv) and x-ray rings of the National Synchrotron Light Source (NSLS). Plans are described for experiments at the NSLS and an exciting development in instrumentation for heavy-ion experiments is summarized.
Date: April 26, 1984
Creator: Johnson, B. M.; Jones, K. W. & Meron, M.
System: The UNT Digital Library
Weak decays at PEP (open access)

Weak decays at PEP

Results are presented on four aspects of weak decays. The MARK II measurement of the tau lifetime, the MARK II measurement of the D/sup 0/ lifetime, the measurement from several experiments of the semi-leptonic branching fractions of hadrons constraining b and c quarks, and lastly the MAC measurement of the B lifetime. 30 references.
Date: April 1, 1984
Creator: Yelton, J. M.
System: The UNT Digital Library
Dynamics of itinerant ferromagnets above T/sub c/ (open access)

Dynamics of itinerant ferromagnets above T/sub c/

The existence of propagating spin waves above T/sub c/ in Ni and Fe has been widely accepted since this picture was first advocated in 1973. In this brief review of our current neutron scattering experiments on Fe and Ni we will present convincing evidence showing that this picture is incorrect. In addition, we will demonstrate that over wide ranges of ..omega.., q and temperature, both Fe and Ni follow a simple paramagnetic scattering function of the spin diffusion type. 19 references.
Date: April 1, 1984
Creator: Shirane, G.; Boeni, P. & Wicksted, J.
System: The UNT Digital Library
High current electron linacs (advanced test accelerator/experimental test accelerator) (open access)

High current electron linacs (advanced test accelerator/experimental test accelerator)

The high current induction accelerator development at the Lawrence Livermore National Laboratory is described. The ATA facility is designed for 10 kA peak currents, 50 nsec pulse lengths and 50 MeV energies. At this time, half of the design current has been accelerated through the entire machine to particle energies of about 45 MeV. Current problem areas and operational experience to date will be discussed. Several key technical areas required development for the ATA machine; this report will survey these developments. The control of transverse beam instabilities required an accelerating cavity design with very low Q. Electron sources capable of 10 kA operation at high rep rates were developed using a plasma sparkboard approach. The pulse power systems on ATA, using the same type of spark gap switches as ETA, have exhibited excellent operational reliability.
Date: April 30, 1984
Creator: Briggs, Richard J.
System: The UNT Digital Library
Study of beta-delayed two-proton emission in /sup 22/Al and /sup 26/P and search for new emitters (open access)

Study of beta-delayed two-proton emission in /sup 22/Al and /sup 26/P and search for new emitters

As predicted by Gol'danskii, nuclei far from stability may decay via the unusual manner of /sup 2/He (or 'diproton') emission. The diproton corresponds to a coupling of two protons in a virtual /sup 1/S/sub 0/ state which subsequently decays to two unbound protons. This /sup 2/He nucleus has been calculated to have an increased probability of barrier penetration relative to the independent emission of two protons. When the energetics permit /sup 2/He emission, two competing modes of two-proton emission are also frequently allowed. These are a sequential proton decay through an intermediate state and the simultaneous emission of two uncoupled protons. Recent studies on /sup 22/Al and /sup 26/P are described and proposed partial decay schemes are given. (WHK)
Date: April 1, 1984
Creator: Cable, M. D.; Honkanen, J.; Schloemer, E. C.; Ahmed, M.; Reiff, J. E.; Zhou, Z. Y. et al.
System: The UNT Digital Library
Defect Production Efficiencies in Thermal Neutron Irradiated Copper and Molybdenum (open access)

Defect Production Efficiencies in Thermal Neutron Irradiated Copper and Molybdenum

We have derived the primary recoil spectra for thermal neutron capture in copper and molybdenum, and have calculated the damage energy cross-sections needed to determine the defect production efficiencies from measured resistivity damage rates. These efficiencies, which are in excellent agreement with fully dynamic computer simulations of collision cascades, are compared to the predictions of displacement functions which are currently in use.
Date: April 24, 1984
Creator: Kinney, J. H.; Guinan, M. W. & Munir, Z. A.
System: The UNT Digital Library
High power testing of the multiple-loop radio-frequency drive concept for the FMIT accelerator (open access)

High power testing of the multiple-loop radio-frequency drive concept for the FMIT accelerator

The Fusion Materials Irradiation Test (FMIT) accelerator requires several 600-kW rf systems to simultaneously supply rf power to a single accelerator tank. Each rf-system output must be carefully phase and amplitude controlled to achieve the proper system performance. Two 80-MHz, 600-kW rf amplifiers with phase- and amplitude-control systems have been tested into a single, high-Q resonant cavity. Experimental results are presented.
Date: April 1, 1984
Creator: Fazio, M. V. & Patton, R. D.
System: The UNT Digital Library
Automatic camera tracking for remote manipulators (open access)

Automatic camera tracking for remote manipulators

The problem of automatic camera tracking of mobile objects is addressed with specific reference to remote manipulators and using either fixed or mobile cameras. The technique uses a kinematic approach employing 4 x 4 coordinate transformation matrices to solve for the needed camera PAN and TILT angles. No vision feedback systems are used, as the required input data are obtained entirely from position sensors from the manipulator and the camera-positioning system. All hardware requirements are generally satisfied by currently available remote manipulator systems with a supervisory computer. The system discussed here implements linear plus on/off (bang-bang) closed-loop control with a +-2/sup 0/ deadband. The deadband area is desirable to avoid operator seasickness caused by continuous camera movement. Programming considerations for camera control, including operator interface options, are discussed. The example problem presented is based on an actual implementation using a PDP 11/34 computer, a TeleOperator Systems SM-229 manipulator, and an Oak Ridge National Laboratory (ORNL) camera-positioning system. 3 references, 6 figures, 2 tables.
Date: April 1, 1984
Creator: Stoughton, R. S.; Martin, H. L. & Bentz, R. R.
System: The UNT Digital Library
Status of the new high intensity H/sup -/ injector at LAMPF (open access)

Status of the new high intensity H/sup -/ injector at LAMPF

The requirement for higher intensity H/sup -/ ion beams for the proton storage ring now being constructed at LAMPF necessitated the development of a new H/sup -/ ion source and the rebuilding of the original H/sup -/ injector and its associated beam transport lines. The goal of the ion source development program was to produce an H/sup -/ beam with a peak intensity of 20 mA at 10% duty factor and with a beam emittance of less than 0.08 cm-mrad normalized at 95% beam fraction. The ion source concept which was best suited to our requirements was the multicusp, surface-production source developed for neutral beam injectors at Berkeley by Ehlers and Leung. An accelerator version of this source has been subsequently developed at Los Alamos to meet these storage ring requirements. The use of these higher intensity H/sup -/ beams, together with the more stringent chopping and bunching requirements entailed in the operation of the storage ring, now requires rebuilding the entire H/sup -/ injector at LAMPF. This construction is in progress. It is anticipated that the new injector will be fully operational by the end of 1984 and that the required H/sup -/ beams will be available for the …
Date: April 1, 1984
Creator: Stevens, R. R. Jr.; York, R. L.; McConnell, J. R. & Kandarian, R.
System: The UNT Digital Library
Assessment of resonance ionization mass spectrometry for analytical chemistry and spectroscopy (open access)

Assessment of resonance ionization mass spectrometry for analytical chemistry and spectroscopy

Resonance ionization mass spectrometry (RIMS) is a natural outgrowth of RIS. The result of an RIS process is an ion pair. The electron can be used to detect the process, and single atom detection has been demonstrated by this method. The cation resulting from the RIS process actually carries more easily accessible and useful information (i.e. the mass of the ion). RIMS is useful in mass analysis. The development of RIMS has proceeded along several different directions, using CW or pulsed lasers, narrow or wide band laser energies, different kinds of sample generation, and different kinds of mass separations. RIMS in various forms can be used to obtain either element or isotope selectivity. Even though the RIMS technique has developed along several lines, several things are common to all approaches. Ultimately RIMS requires gaseous, free, atoms. RIMS makes use of the photoionization of these atoms by absorption of photons through allowed transitions involving real energy levels. The ion once formed is detected by standard mass spectrometric techniques.
Date: April 20, 1984
Creator: Young, J. P.; Donohue, D. L. & Smith, D. H.
System: The UNT Digital Library
3081/E processor (open access)

3081/E processor

The 3081/E project was formed to prepare a much improved IBM mainframe emulator for the future. Its design is based on a large amount of experience in using the 168/E processor to increase available CPU power in both online and offline environments. The processor will be at least equal to the execution speed of a 370/168 and up to 1.5 times faster for heavy floating point code. A single processor will thus be at least four times more powerful than the VAX 11/780, and five processors on a system would equal at least the performance of the IBM 3081K. With its large memory space and simple but flexible high speed interface, the 3081/E is well suited for the online and offline needs of high energy physics in the future.
Date: April 1, 1984
Creator: Kunz, P. F.; Gravina, M.; Oxoby, G.; Rankin, P.; Trang, Q.; Ferran, P. M. et al.
System: The UNT Digital Library
Practical aspects of tuning a ringed RFQ (open access)

Practical aspects of tuning a ringed RFQ

A radio-frequency quadrupole (RFQ) constructed at Los Alamos for high-current H/sup -/ operation at 425 MHz and 2.0-MeV output energy has been retrofitted with vane coupling rings (VCRS) introduced at Berkeley. The initial set of seven complete VCR pairs produced excessive operating frequency change, and an arrangement of alternating horizontal and vertical coupling rings eventually was adopted. Because of the periodicity and length of the system, end effects were pronounced. A new type of end tuner was used to adjust the field strength at the ends of the structure that should be of general utility for high-power RFQs. Tuning data for various ring and tuning configurations are given. Operating data are given in a companion paper. 2 references, 7 figures, 1 table.
Date: April 1, 1984
Creator: Purser, F. O.; Potter, J. M. & Humphry, F. J.
System: The UNT Digital Library
Isolated grid electron gun and pulser system for long/short pulse operation (open access)

Isolated grid electron gun and pulser system for long/short pulse operation

The new NPI gun at SLAC serves the dual functions of producing long pulse (up to 5 ..mu..sec, 180 pps) electron bursts for nuclear physics experiments, and also short (1 nsec) pulses for filling Stanford Synchrotron Radiation Laboratory (SSRL). This is accomplished by means of a newly designed, isolated grid gun, cathode pulsed with a solid state long pulse pulser, and grid pulsed with a fast recharging avalanche type short pulse (1 nsec) grid pulser. The grid pulser is bipolar so that a fast blackout notch can be placed in the long cathode pulse. This fast notch can be seen by Stanford Linear Collider (SLC) instrumentation and allows the long pulse beam to be computer controlled by SLC intensity and beam position monitors.
Date: April 1, 1984
Creator: Koontz, R. F.; Feathers, L.; Kilbourne, C.; Leger, G. & McKinney, T.
System: The UNT Digital Library
Hazardous materials information hotline using System 2000 (open access)

Hazardous materials information hotline using System 2000

The Center for Assessment of Chemical and Physical Hazards (CACPH) at Brookhaven National Laboratory (BNL) has developed a computer hotline service for the Department of Energy (DOE) and its contractors. This service provides access to health and safety information for over 800 chemicals and hazardous materials. The data base uses System 2000 on a CDC 6600 and provides information on the chemical name and its synonyms, 17 categories of health and safety information, composition of chemical mixtures, categories of chemicals, use and hazards, and physical, chemical and toxicity attributes. In order to make this information available to people unfamiliar with System 2000, a user-friendly interface was developed using a Fortran PLEX Program. 1 reference, 1 figure.
Date: April 30, 1984
Creator: Brower, J. E. & Fuchel, K.
System: The UNT Digital Library
Dependence of laser-plasma interaction physics on laser wavelength and plasma scalelength (open access)

Dependence of laser-plasma interaction physics on laser wavelength and plasma scalelength

We discuss the dependence of many features of laser-plasma interaction physics on both the laser wavelength and plasma dimensions. Experimental results that are presented include absorption, stimulated Brillouin scattering, suprathermal electron production, and optical signatures of the two plasmon decay and stimulated Raman instabilities. While the experiments show beneficial effects of decreasing laser wavelength on the coupling physics, the mix and efficiency of the various interaction processes is shown to be strongly dependent on the size of the underdense plasma. 42 refs., 20 figs., 5 tabs.
Date: April 9, 1984
Creator: Campbell, E. M.
System: The UNT Digital Library
Proceedings of the workshop on prospects for research with radioactive beams from heavy ion accelerators (open access)

Proceedings of the workshop on prospects for research with radioactive beams from heavy ion accelerators

The SuperHILAC Users Executive Committee organized a workshop on Prospects for Research with Radioactive Beams from Heavy Ion Accelerators. The main purpose of the workshop was to bring together a diverse group of scientists who had already done experients with radioactive beams or were interested in their use in the future. The topics of the talks ranged from general nuclear physics, astrophysics, production of radioactive beams and high energy projectile fragmentation to biomedical applications. This publication contains the abstracts of the talks given at the workshop and copies of the viewgraphs as they were supplied to the editor.
Date: April 1, 1984
Creator: Nitschke, J.M. (ed.)
System: The UNT Digital Library
Proceedings of the seventeenth LAMPF Users Group meeting (open access)

Proceedings of the seventeenth LAMPF Users Group meeting

The seventeenth annual LAMPF Users Group meeting was held November 7-8, 1983, at the Clinton P. Anderson Meson Physics Facility. The program included a number of invited talks on various aspects of nuclear and particle physics as well as status reports on LAMPF. A panel discussion on the LAMPF II concept provided an exchange of views among an advisory group, Users, and LAMPF staff. The LAMPF working groups met and discussed plans for each of the secondary beam lines.
Date: April 1, 1984
Creator: Bradbury, James N.
System: The UNT Digital Library
Experiments on statistical mechanics using resonance ionization spectroscopy (open access)

Experiments on statistical mechanics using resonance ionization spectroscopy

Five different fluctuation phenomena at the atomic and molecular levels have been studied by resonance ionization spectroscopy techniques with one-atom detection sensitivity. The Poisson distribution described the observed frequency distributions suggesting random behavior. In addition, a gedanken experiment suggested by Einstein and Furth on the diffusion of atoms was performed in order to test the equality between time and ensemble averages. The obtained results confirmed the ergodicity of the studied system.
Date: April 1, 1984
Creator: Iturbe, J.; Allman, S. L.; Hurst, G. S. & Payne, M. G.
System: The UNT Digital Library
Workshop on nuclear dynamics III (open access)

Workshop on nuclear dynamics III

Separate entries were made in the data base for the 49 papers presented. (WHK)
Date: April 1, 1984
Creator: Viola, V.E. Jr. (ed.)
System: The UNT Digital Library