Proceedings of the LAMPF workshop on physics with polarized nuclear targets (open access)

Proceedings of the LAMPF workshop on physics with polarized nuclear targets

Topics of discussion included static and dynamic methods for polarizing nuclei, proton and pion nucleus scattering experiments, and possible future experiments at LAMPF. Separate abstracts were prepared for 11 papers in this report. (DWL)
Date: August 1, 1986
Creator: Burleson, G.; Gibbs, W.; Hoffmann, G.; Jarmer, J. J. & Tanaka, N. (eds.)
System: The UNT Digital Library
Construction and testing of the Mirror Fusion Test Facility magnets (open access)

Construction and testing of the Mirror Fusion Test Facility magnets

This paper describes the construction and testing of the Mirror Fusion Test Facility superconducting magnet set. Construction of the first Yin Yang magnet was started in 1978. And although this particular magnet was later modified, the final construction of these magnets was not completed until 1985. When completed these 42 magnets weighed over 1200 tonnes and had a maximum stored energy of approximately 1200 MJ at full field. Together with power supplies, controls and liquid nitrogen radiation shields the cost of the fabrication of this system was over $100M. General Dynamics/Convair Division was responsible for the system design and the fabrication of 20 of the magnets. This contract was the largest single procurement action at the Lawrence Livermore National Laboratory. During the PACE acceptance tests, the 26 major magnets were operated at full field for more than 24 hours while other MFTF subsystems were tested. From all of the data, the magnets operated to the performance specifications. For physics operation in the future, additional helium and nitrogen leak checking and repair will be necessary. In this report we will discuss the operation and testing of the MFTF Magnet System, the world's largest superconducting magnet set built to date. The topics …
Date: August 1, 1986
Creator: Kozman, T.; Shimer, D.; VanSant, J. & Zbasnik, J.
System: The UNT Digital Library
Nuclear alkali metal Rankine power systems for space applications (open access)

Nuclear alkali metal Rankine power systems for space applications

Nucler power systems utilizing alkali metal Rankine power conversion cycles offer the potential for high efficiency, lightweight space power plants. Conceptual design studies are being carried out for both direct and indirect cycle systems for steady state space power applications. A computational model has been developed for calculating the performance, size, and weight of these systems over a wide range of design parameters. The model is described briefly and results from parametric design studies, with descriptions of typical point designs, are presented in this paper.
Date: August 1, 1986
Creator: Moyers, J. C. & Holcomb, R. S.
System: The UNT Digital Library
Theoretical understanding of charm decays (open access)

Theoretical understanding of charm decays

A detailed description of charm decays has emerged. The various concepts involved are sketched. Although this description is quite successful in reproducing the data the chapter on heavy flavour decays is far from closed. Relevant questions like on th real strength of weak annihilation, Penguin operators, etc. are still unanswered. Important directions in future work, both on the experimental and theoretical side are identified.
Date: August 1, 1986
Creator: Bigi, I. I.
System: The UNT Digital Library
Fermilab Tevatron and Pbar source status report (open access)

Fermilab Tevatron and Pbar source status report

The antiproton production cycle is enumerated, and the commissioning of the antiproton source is described, giving milestones and major obstacles. The Tevatron collider operation is described, including procedure to load the Tevatron with three bunches of protons and three bunches of antiprotons. Commissioning of the Main Ring and Tevatron for collider operation is described. Development and accelerator studies in four areas were necessary: main ring RF manipulations; controls and applications software support; Tevatron storage and low-beta squeeze sequence; and study of various beam transfers, storage steps, and sequences. Final tests are described. A long range upgrade program is presently under evaluation to accomplish these goals: luminosity increase to 5 x 10/sup 31/ cm/sup -2/sec/sup -1/, production rates up to 4 x 10/sup 11/ antiprotons/hr, and intensity increase for fixed target operation. Beam quality is to be improved by the injector and main ring upgrades, and the luminosity goal is addressed by the Collider upgrade. (LEW)
Date: August 1, 1986
Creator: Edwards, H.
System: The UNT Digital Library
Convective heat transport in geothermal systems (open access)

Convective heat transport in geothermal systems

Most geothermal systems under exploitation for direct use or electrical power production are of the hydrothermal type, where heat is transferred essentially by convection in the reservoir, conduction being secondary. In geothermal systems, buoyancy effects are generally important, but often the fluid and heat flow patterns are largely controlled by geologic features (e.g., faults, fractures, continuity of layers) and location of recharge and discharge zones. During exploitation, these flow patterns can drastically change in response to pressure and temperature declines, and changes in recharge/discharge patterns. Convective circulation models of several geothermal systems, before and after start of fluid production, are described, with emphasis on different characteristics of the systems and the effects of exploitation on their evolution. Convective heat transport in geothermal fields is discussed, taking into consideration (1) major geologic features; (2) temperature-dependent rock and fluid properties; (3) fracture- versus porous-medium characteristics; (4) single- versus two-phase reservoir systems; and (5) the presence of noncondensible gases.
Date: August 1, 1986
Creator: Lippmann, M.J. & Bodvarsson, G.S.
System: The UNT Digital Library
Gaugino masses in superstring inspired models (open access)

Gaugino masses in superstring inspired models

Contributions to the masses of the gauginos in models arising as low energy limits of superstring theories are considered.
Date: August 1, 1986
Creator: Dawson, S.
System: The UNT Digital Library
Numerical models for the evaluation of geothermal systems (open access)

Numerical models for the evaluation of geothermal systems

We have carried out detailed simulations of various fields in the USA (Bada, New Mexico; Heber, California); Mexico (Cerro Prieto); Iceland (Krafla); and Kenya (Olkaria). These simulation studies have illustrated the usefulness of numerical models for the overall evaluation of geothermal systems. The methodology for modeling the behavior of geothermal systems, different approaches to geothermal reservoir modeling and how they can be applied in comprehensive evaluation work are discussed.
Date: August 1, 1986
Creator: Bodvarsson, G.S.; Pruess, K. & Lippmann, M.J.
System: The UNT Digital Library
Tests of quantum electrodynamics in few-electron very high-Z ions (open access)

Tests of quantum electrodynamics in few-electron very high-Z ions

This article discusses our measurement of the Lamb shift in heliumlike uranium and outlines future tests of QED using few- electron very high atomic number (Z) ions. Our recently reported Lamb shift value of 70.4 (8.1) eV for the one- electron Lamb shift in uranium is in agreement with the theoretical value of 75.3 (0.4) eV. The experimental value was extracted from a beam-foil time-of-flight measurement of the 54.4 (3.3) ps lifetime of the 1s2p/sub 1/2/ /sup 3/P/sub 0/ state of heliumlike uranium. 24 refs., 5 figs., 1 tab.
Date: August 1, 1986
Creator: Gould, H. & Munger, C.T.
System: The UNT Digital Library
Applications of the MEVVA high current metal ion source (open access)

Applications of the MEVVA high current metal ion source

A new kind of ion source has been developed in which a metal vapor vacuum arc (MEVVA) is used to produce the plasma from which the ion beam is extracted. The novel and exciting feature of this source is the very high metal ion beam current attainable. A total ion beam current of over 1 Ampere has been extracted from the embodiment of the concept that we're presently using, and this is not a limit of the method. The source was developed to upgrade the uranium ion beam intensity of the Bevatron, LBL's heavy ion synchrotron, for basic nuclear physics research. Other important applications include its use within the Heavy Ion Fusion research effort; for ion implantation; and for other basic research uses. In this paper the source is described briefly, its performance outlined, and its poential and limitations for a variety of applications is discussed.
Date: August 1, 1986
Creator: Brown, I.G.
System: The UNT Digital Library
Harmonic superspace formalism and the consistent chiral anomaly (open access)

Harmonic superspace formalism and the consistent chiral anomaly

The harmonic superspace formalism has been used to construct the consistent chiral anomaly in N = 1, d = 6 supersymmetric Yang-Mills thoery. The expressions of the gauge anomaly ..delta../sub s//sup phi/ and of the supersymmetric anomaly ..delta../sub SUSY//sup phi/ are given together with the consistent condition. 7 refs.
Date: August 1, 1986
Creator: Li, W.
System: The UNT Digital Library
Impedance of a beam tube with antechamber (open access)

Impedance of a beam tube with antechamber

A beam vacuum chamber was proposed to allow synchrotron light to radiate from a circulating electron beam into an antechamber containing photon targets, pumps, etc. To determine the impedance such a geometry would present to the beam, electromagnetic measurements were carried out on a section of chamber using for low frequencies a current-carrying wire and for up to 16 GHz, a resonance perturbation method. Because the response of such a chamber would depend on upstream and downstream restrictions of aperture yet to be determined, the resonance studies were analyzed in some generality. The favorable conclusion of these studies is that the antechamber makes practically no contribution to either the longitudinal or the transverse impedances.
Date: August 1, 1986
Creator: Barry, W.; Lambertson, G.R. & Voelker, F.
System: The UNT Digital Library
Design and characterization for absolute x-ray spectrometry in the 100-10,000 eV region (open access)

Design and characterization for absolute x-ray spectrometry in the 100-10,000 eV region

Reviewed here are the design and characterization procedures used in our program for developing absolute x-ray spectrometry in the 100 to 10,000 eV region. Described are the selection and experimental calibration of the x-ray filters, mirror momochromators, crystal/multilayer analyzers, and the photographic (time integrating) and photoelectric (time resolving) position-sensitive detectors. Analytical response functions have been derived that characterize the energy dependence of the mirror and crystal/multilayer reflectivities and of the photographic film and photocathode sensitivities. These response functions permit rapid, small-computer reduction of the experimental spectra to absolute spectra (measured in photons per stearadian from the source for radiative transitions at indicated photon energies). Our x-ray spectrographic systems are being applied to the diagnostics of pulsed, high temperature plasma sources in laser fusion and x-ray laser research. 15 refs., 27 figs.
Date: August 1, 1986
Creator: Henke, B.L.
System: The UNT Digital Library
Light ion program at BNL (open access)

Light ion program at BNL

At Brookhaven National Laboratory (BNL) two existing facilities, the Tandem Van de Graaff machines and the AGS have been joined by a beam transfer line, and modified to permit acceleration of light ions (up to sulfur) to energies of 14.6 GeV/amu. Light ions supplied by a pulsed ion source are accelerated by the Tandem to an energy of about 7 to 8 MeV/amu, and are transferred directly into the AGS in the fully stripped state. In the AGS an auxiliary rf system has been added to accelerate through the low velocity region from about 7 to about 200 MeV/amu, at which point the previously existing AGS RF system takes over to complete the acceleration cycle to full energy, as it normally does for protons. Standard resonant slow extraction delivers the beam to the existing experimental beam facilities. This is the first phase of a long range program to provide facilities for relativistic heavy ion experiments with fixed targets and ultimately with colliding beams at BNL. The design objectives for this project and preliminary results obtained during the commissioning of the light ion program are described in this paper. Plans for a future second phase, a booster accelerator to permit heavy …
Date: August 1, 1986
Creator: Foelsche, H.; Barton, D. S. & Thieberger, P.
System: The UNT Digital Library
Simulation of synchrotron motion with rf noise (open access)

Simulation of synchrotron motion with rf noise

The theoretical formulation is described that is behind an algorithm for synchrotron phase-space tracking with rf noise and some preliminary simulation results of bunch diffusion under rf noise obtained by actual tracking.
Date: August 1, 1986
Creator: Leemann, B.T.; Forest, E. & Chattopadhyay, S.
System: The UNT Digital Library
High-resolution CT system for elemental mapping (open access)

High-resolution CT system for elemental mapping

The performance of a low-temperature CCD camera for application in computed tomography (CT) was tested on beamline II-3 at the Stanford Synchrotron Radiation Laboratory (SSRL). In the present system, transmitted x-rays are converted to visible light on a phosphor-coated optical face plate. This light illuminates a thermoelectrically cooled CCD, which is operated as a charge counting device. By modulating the energy of the x-ray beam, we can obtain elemental and chemical-state information about the reconstructed voxels. Presently, the resolution is about 50 microns, and is to a large extent controlled by the quality of the phosphor. The spatial resolution and chemical sensitivity of the system are reported. Applications to materials and biological sciences are discussed.
Date: August 1, 1986
Creator: Kinney, J.H.; Johnson, Q.C.; Brase, J.M.; Nichols, M.C.; Nusshardt, R. & Bonse, U.
System: The UNT Digital Library
Application of Synchrotron Radiation to X-Ray Fluorescence Analysis of Trace Elements (open access)

Application of Synchrotron Radiation to X-Ray Fluorescence Analysis of Trace Elements

The development of synchrotron radiation x-ray sources has provided the means to greatly extend the capabilities of x-ray fluorescence analysis for determinations of trace element concentrations. A brief description of synchrotron radiation properties provides a background for a discussion of the improved detection limits compared to existing x-ray fluorescence techniques. Calculated detection limits for x-ray microprobes with micrometer spatial resolutions are described and compared with experimental results beginning to appear from a number of laboratories. The current activities and future plans for a dedicated x-ray microprobe beam line at the National Synchrotron Light Source (NSLS) of Brookhaven National Laboratory are presented.
Date: August 1, 1986
Creator: Gordon, B. M.; Jones, K. W. & Hanson, A. L.
System: The UNT Digital Library
Effects of wigglers and undulators on beam dynamics (open access)

Effects of wigglers and undulators on beam dynamics

Synchrotron light facilities are making ever increasing use of wigglers and undulators, to the extent that these devices are becoming a significant part of the beam optical system of the storage ring itself. This paper presents a theoretical formulation for investigating the effect of wigglers and undulators on beam dynamics in the approximation that the wiggler parameter, K, divided by ..gamma.. is a small number and that the number of wiggler periods in one device is large. In addition to the linear forces which must be taken into account when tuning and matching the ring, nonlinear stop bends are created, with even orders more serious than odd orders. Some numerical examples are given for devices similar to those proposed for the 1-2 GeV Synchrotron Radiation Source at Lawrence Berkeley Laboratory.
Date: August 1, 1986
Creator: Smith, L.
System: The UNT Digital Library
Improved understanding of first-mall vaporization-condensation in inertial confinement fusion reactors. Revision 1 (open access)

Improved understanding of first-mall vaporization-condensation in inertial confinement fusion reactors. Revision 1

We report approximate x-ray and debris spectra emanating from a region of compressed DT fuel representing the imploded configuration of a generic direct-drive ICF reactor pellet. We show how the spectra are modified by spherical lead shields of various thicknesses placed near the pellet, and show that it is not possible to lessen the ablation of the first wall or blanket of a low-pressure ICF reactor chamber through use of such shields. Then we report that the calculated x-ray spectra alone (i.e., without the associated debris) cause vaporization of a first wall placed at a radius of 4 m that is much more than previously expected. This result increases the importance of understanding the details of the vaporization and condensation phenomena.
Date: August 1, 1986
Creator: Orth, C.D.
System: The UNT Digital Library
Lifetimes of heavy flavour particles (open access)

Lifetimes of heavy flavour particles

Recent measurements of the lifetimes of charm and beauty particles are reviewed, with emphasis on the experimental techniques used for vertex detection. 44 refs., 9 figs., 3 tabs.
Date: August 1, 1986
Creator: Lueth, V.
System: The UNT Digital Library
Damping rings for achieving ultra-small electron beam emittance (open access)

Damping rings for achieving ultra-small electron beam emittance

Production of low emittance beams at injection is examined via a computer simulation program. Two machines were studied using the simulation program, both of which were assumed circular with no straight sections, with radii of 100 and 1000 meters. The program accounts for first order beam transport, damping from energy loss due to synchrotron radiation, excitation from the quantum nature of the radiation, beam excitation due to the presence of gas molecules in the beam pipe, magnet errors, beam growth due to intrabeam scattering, and the effect of wakefields induced in the rf cavity. The machines considered are found to be feasible and to have small emittances. Intrabeam scattering is found to be the dominant process affecting the beam emittance. (LEW)
Date: August 1, 1986
Creator: Hand, L. N. & Vinson, M. J.
System: The UNT Digital Library
Substructure: a brief summary (open access)

Substructure: a brief summary

The present status of substructure theories for Higgs particles, quarks, leptons and gauge bosons is briefly summarized.
Date: August 1, 1986
Creator: Harari, H.
System: The UNT Digital Library
Improvements to the helium-jet coupled on-line mass separator RAMA (open access)

Improvements to the helium-jet coupled on-line mass separator RAMA

Some general improvements to the on-line mass separator RAMA have yielded a factor of five increase in yield for most elements. By placing the ion source region at the full accelerating potential of 20 kV, the effective skimmer-plasma distance has been reduced from 12 cm to <2 cm. Changes in the helium-jet chamber and large volume pumping arrangement necessitated by placing the ion source region at high voltage are also given. Finally, details for a new highly shielded detector station are presented.
Date: August 1, 1986
Creator: Bloennigen, F. B.; Moltz, D. M.; Lang, T. F.; Knoll, W. F.; Xu, X.; Hotchkis, M. A. C. et al.
System: The UNT Digital Library
Soft x-ray imaging system for measurement of noncircular tokamak plasmas (open access)

Soft x-ray imaging system for measurement of noncircular tokamak plasmas

A soft x-ray camera and image processing system has been constructed to provide measurements of the internal shape of high temperature tokamak plasmas. The camera consists of a metallic-foil-filtered pinhole aperture and a microchannel plate image intensifier/convertor which produces a visible image for detection by a CCD TV camera. A wide-angle tangential view of the toroidal plasma allows a single compact camera to view the entire plasma cross section. With Be filters 12 to 50 ..mu..m thick, the signal from the microchannel plate is produced mostly by nickel L-line emissions which orignate in the hot plasma core. The measured toroidal image is numerically inverted to produce a cross-sectional soft x-ray image of the plasma. Since the internal magnetic flux surfaces are usually isothermal and the nickel emissivity depends strongly on the local electron temperature, the x-ray emission contours reflect the shape of the magnetic surfaces in the plasma interior. Initial results from the PBX tokamak experiment show clear differences in internal plasma shapes for circular and bean-shaped discharges.
Date: August 1, 1986
Creator: Fonck, R.J.; Reusch, M.; Jaehnig, K.P.; Hulse, R. & Roney, P.
System: The UNT Digital Library