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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
Adaptive Mesh Refinement for 1-Dimensional Gas Dynamics (open access)

Adaptive Mesh Refinement for 1-Dimensional Gas Dynamics

We consider the solution of the one-dimensional equation of gas-dynamics. Accurate numerical solutions are difficult to obtain on a given spatial mesh because of the existence of physical regions where components of the exact solution are either discontinuous or have large gradient changes. Numerical methods treat these phenomena in a variety of ways. In this paper, the method of adaptive mesh refinement is used. A thorough description of this method for general hyperbolic systems is given elsewhere and only properties of the method pertinent to the system are elaborated.
Date: 1982-08~
Creator: Hedstrom, Gerald; Rodrigue, Garry; Berger, Marsha & Oliger, Joseph
System: The UNT Digital Library
Some recent developments in nuclear charged particle detectors (open access)

Some recent developments in nuclear charged particle detectors

The latest developments of large-area, position sensitive gas-filled ionization chambers are described. Multi-wire-proportional chambers as position-sensing and parallel-plate-avalanche counters as time-sensing detectors at low pressure (5 torr) have proven to be useful and reliable instruments in heavy ion physics. Gas (proportional) scintillation counters, used mainly for x-ray spectroscopy, have recently been applied as particle detectors. Finally, a brief description of a large plastic scintillator spectrometer, the Plastic Ball, is given and some of the first test and calibration data are shown.
Date: August 1, 1980
Creator: Stelzer, H.
System: The UNT Digital Library
Progress report on the development of the General Atomic thermochemical water-splitting process (open access)

Progress report on the development of the General Atomic thermochemical water-splitting process

The major accomplishments of the DOE funded part of the GA thermochemical water-splitting program are reported. They include: completion of installation of all bench-scale equipment; operation and preliminary data acquisition for bench-scale subunits I and II; design, installation and operation of a system for iodine removal from the low phase; review and modification of Section III of the engineering flowsheet resulting in an increase in process efficiency and decrease in capital cost; and completion of the Funk panel reivew. The results of the experimental work have demonstrated that flowsheet conditions can be achieved in all cases tested. Continued work on the flowsheet has increased our confidence in the economic viability of the sulfur-iodine process.
Date: August 1, 1980
Creator: Besenbruch, G.E.; Allen, C.L.; Brown, L.C.; McCorkle, K.; Rode, J.S.; Norman, J.H. et al.
System: The UNT Digital Library
The U5. 0 undulator design for the advanced light source at LBL (open access)

The U5. 0 undulator design for the advanced light source at LBL

The U5.0 undulator, currently under design, is the first in a series of insertion devices planned for the Advanced Light Source at LBL. U5.0 parameters include a 5 cm period, 5 m length with a 0.837 T maximum field at a 14 mm gap. A hybrid configuration utilizing Nd-Fe-B permanent magnet material and Vanadium Permendur poles is used for the magnetic structure. Construction is modular with many pole assemblies attached to a pole mount, which in turn is fastened onto one of the backing beams. Vertical field integral correction at the ends is with permanent magnet rotators. The supports structure features a 4-post configuration, a rigid base with 3 kinematic floor supports and 2 rigid 5 m long backing beams that fit within the 2.4 m high accelerator enclosure. The drive system is computer controlled utilizing a stepper motor and shaft encode coupled to a roller-screw/nut and chain drive train. Vacuum chamber design is a rigid configuration with a 10 mm vertical by 218 mm horizontal aperture of 5.5 m length. Chamber fabrication features a two-piece welded chamber of 5083 H321 aluminum. Pumping is with ion and titanium sublimation pumps. 5 figs., 1 tab.
Date: August 1, 1989
Creator: Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.; Humphries, D.; Kincaid, B. et al.
System: The UNT Digital Library
Methods of driving current by heating a toroidal plasma (open access)

Methods of driving current by heating a toroidal plasma

In addition to the usual mechanism which utilizes the Ohmic transformer current, which is necessarily pulsed, there exist several steady-state mechanisms. Heating mechanisms which can lend themselves efficiently to continuous current generation include neutral beams, Alfven waves, ion-cyclotron waves, lower-hybrid waves and electron-cyclotron waves.
Date: August 1, 1980
Creator: Fisch, N. J.
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
Physics of antimatter-matter reactions for interstellar propulsion (open access)

Physics of antimatter-matter reactions for interstellar propulsion

At the stage of the antiproton-nucleon annihilation chain of events relevant to propulsion the annihilation produces energetic charged pions and gamma rays. If annihilation occurs in a complex nucleus, protons, neutrons, and other nuclear fragments are also produced. The charge, number, and energy of the annihilation products are such that annihilation rocket engine concepts involving relatively low specific impulse (I/sub sp/ approx. = 1000 to 2000 s) and very high I/sub sp/ (3 x 10/sup 7/ s) appear feasible and have efficiencies on the order of 50% for annihilation energy to propulsion energy conversion. At I/sub sp/'s of around 15,000 s, however, it may be that only the kinetic energy of the charged nuclear fragments can be utilized for propulsion in engines of ordinary size. An estimate of this kinetic energy was made from known pieces of experimental and theoretical information. Its value is about 10% of the annihilation energy. Control over the mean penetration depth of protons into matter prior to annihilation is necessary so that annihilation occurs in the proper region within the engine. Control is possible by varying the antiproton kinetic energy to obtain a suitable annihilation cross section. The annihilation cross section at low energies is …
Date: August 22, 1986
Creator: Morgan, D.L. Jr.
System: The UNT Digital Library
HTGR safety philosophy (open access)

HTGR safety philosophy

The accident at the Three Mile Island has focused public attention on reactor safety. Many public figures advocate a safer method of generating nuclear electricity for the second nuclear era in the US. The paper discusses the safety philosophy of a concept deemed suitable for this second nuclear era. The HTGR, in the course of its evolution, included safety as a significant determinant in design philosophy. This is particularly evident in the design features which provide inherent safety. Inherent features cause releases from a wide spectrum of accident conditions to be low. Engineered features supplement inherent features. The significance of HTGR safety features is quantified and order-of-magnitude type of comparisons are made with alternative ways of generating electricity.
Date: August 1, 1980
Creator: Joskimovic, V. & Fisher, C.R.
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
Suppression of superheavy magnetic monopoles in grand unified theories (open access)

Suppression of superheavy magnetic monopoles in grand unified theories

The superheavy magnetic monopoles predicted by grand unified theories would not be produced in significant numbers if electromagnetic gauge invariance is spontaneously broken when the temperature T is greater than T/sub c/ >approx. 1 TeV.
Date: August 1, 1980
Creator: Pi, S.Y.
System: The UNT Digital Library
Advanced materials for geothermal energy processes (open access)

Advanced materials for geothermal energy processes

The primary goal of the geothermal materials program is to ensure that the private sector development of geothermal energy resources is not constrained by the availability of technologically and economically viable materials of construction. This requires the performance of long-term high risk GHTD-sponsored materials R and D. Ongoing programs described include high temperature elastomers for dynamic sealing applications, advanced materials for lost circulation control, waste utilization and disposal, corrosion resistant elastomeric liners for well casing, and non-metallic heat exchangers. 9 refs.
Date: August 1, 1985
Creator: Kukacka, L. E.
System: The UNT Digital Library
Exact integrability in quantum field theory (open access)

Exact integrability in quantum field theory

The treatment of exactly integrable systems in various branches of two-dimensional classical and quantum physics has recently been placed in a unified framework by the development of the quantum inverse method. This method consolidates a broad range of developments in classical nonlinear wave (soliton) physics, statistical mechanics, and quantum field theory. The essential technique for analyzing exactly integrable quantum systems was invested by Bethe in 1931. The quantum-mechanical extension of the inverse scattering method and its relationship to the methods associated with Bethe's ansatz are examined here. (RWR)
Date: August 1, 1980
Creator: Thacker, H.B.
System: The UNT Digital Library
Photoemission from solids: the transition from solid-state to atomic physics (open access)

Photoemission from solids: the transition from solid-state to atomic physics

As the photon energy is increased, photoemission from solids undergoes a slow transition from solid-state to atomic behavior. However, throughout the energy range h..nu.. = 10 to 1000 eV or higher both types of phenomena are present. Thus angle-resolved photoemission can only be understood quantitatively if each experimenter recognizes the presence of band-structure, photoelectron diffraction, and photoelectron asymmetry effects. The quest for this understanding will build some interesting bridges between solid-state and atomic physics and should also yield important new insights about the phenomena associated with photoemission.
Date: August 1, 1980
Creator: Shirley, D.A.
System: The UNT Digital Library
Measurement of Inclusive Eta Production in e/sup +/e/sup -/ Interactions Near Charm Threshold (open access)

Measurement of Inclusive Eta Production in e/sup +/e/sup -/ Interactions Near Charm Threshold

The inclusive cross section for eta production in e/sup +/e/sup -/ interactions near charm threshold was measured by use of the Crystal Ball detector at SPEAR. By comparison of the inclusive eta production above and below charm threshold the following limits were obtained: R(e/sup +/e/sup -/ ..-->.. F anti FX)BR(F ..-->.. eta x) < 0.3 (90% C.L., E/sub cm/ < 4.5 GeV); BR(D ..-->.. eta x) < 0.13 (90% C.L., averaged over charged and neutral D components of the psi''). 4 figures, 1 table.
Date: August 1, 1980
Creator: Porter, F. C.
System: The UNT Digital Library
Multilayer optical elements for generation and analysis of circularly polarized x-rays (open access)

Multilayer optical elements for generation and analysis of circularly polarized x-rays

Calculations of the relative phase changes of {sigma} and {pi} electric field components on Bragg reflection from and transmission through multilayers are presented. Large relative phase changes can be calculated in certain cases, which may lead to utility of multilayers as quarter-wave plates for generation and analysis of circularly polarized soft x-radiation. Similar behavior may be expected for perfect crystals in the hard x-ray range. 24 refs., 4 figs.
Date: August 1, 1989
Creator: Kortright, J.B. & Underwood, J.H.
System: The UNT Digital Library
Probabilistic risk assessment of HTGRs (open access)

Probabilistic risk assessment of HTGRs

Probabilistic Risk Assessment methods have been applied to gas-cooled reactors for more than a decade and to HTGRs for more than six years in the programs sponsored by the US Department of Energy. Significant advancements to the development of PRA methodology in these programs are summarized as are the specific applications of the methods to HTGRs. Emphasis here is on PRA as a tool for evaluating HTGR design options. Current work and future directions are also discussed.
Date: August 1980
Creator: Fleming, K. N.; Houghton, W. J.; Hannaman, G. W. & Joksimovic, V.
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
Physics at hadron colliders: Experimental view (open access)

Physics at hadron colliders: Experimental view

The physics of the hadron-hadron collider experiment is considered from an experimental point of view. The problems encountered in determination of how well the standard model describes collider results are discussed. 53 refs., 58 figs.
Date: August 1, 1987
Creator: Siegrist, J.L.
System: The UNT Digital Library
Addition of bromine as a diagnostic gas to inertial confinement fusion target microspheres (open access)

Addition of bromine as a diagnostic gas to inertial confinement fusion target microspheres

Currently, direct fuel rho r measurements on Inertial Confinement Fusion (ICF) targets by neutron activation of the argon tracer gas mixed with the DT fuel would require a 100 fold increase in neutron yield. Bromine, on the other hand, has excellent properties for neutron activation analysis at neutron yields of 10two' to 10/sup 8/, when present at an internal pressure of from 0.1 to 0.2 atmospheres. Bromine addition is accomplished in a 2 furnace system using the dried-gel method of microsphere production. An upper furnace operated at 1500/sup 0/C is separated from a lower furnace by a cooled zone. The lower furnace is filled with bromine gas and operated at approximately 1250/sup 0/C. The upper furnace is the glass production furnace. The cooled zone in between the upper and lower furnace is to prevent the hot bromine gas from rising into the upper furnace. The microspheres pass through the cooled zone and immediately into the 1250/sup 0/C bromine furnace where the bromine permeates into the spheres.
Date: August 22, 1980
Creator: Morrison, R. L.
System: The UNT Digital Library
An assessment of the effects of radiation on permanent magnet material in the ALS (Advanced Light Source) insertion devices (open access)

An assessment of the effects of radiation on permanent magnet material in the ALS (Advanced Light Source) insertion devices

Electrons that are lost from the beam during normal operation of a synchrotron radiation source and during a beam dump at the end of a run produce both ionizing radiation and neutrons. This radiation has the potential for damaging sensitive materials, in particular those that need to be very close to the beam. The wigglers and undulators for the Advanced Light Source (ALS) at LBL will use magnetic materials such as the very high performance neodymium-iron-boron, which will be as close as 1 cm away from the electron beam during operation. This material, which is preferred because of its high remanence, is known to be more sensitive to radiation than some other magnetic materials. Simple energy loss estimates and the EGS4 code were used to estimate the radiation levels in the ALS insertion devices in the regions of the magnetic materials. The radiation levels were estimated for both aluminum and stainless steel vacuum chambers to determine if one would provide significantly better shielding. We conclude that Nd-Fe-B can be used in the ALS insertion devices and that there is little difference in the radiation levels for aluminum and stainless vacuum vessels. 8 refs., 7 figs., 1 tab.
Date: August 1, 1989
Creator: Hassenzahl, W. V.; Jenkins, T. M.; Namito, Y.; Nelson, W. R. & Swanson, W. P.
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