Technician support for operation and maintenance of large fusion experiments: the tandem mirror experiment upgrade (TMX-U) approach (open access)

Technician support for operation and maintenance of large fusion experiments: the tandem mirror experiment upgrade (TMX-U) approach

As experiments continue to grow in size and complexity, a few technicians will no longer be able to maintain and operate the complete experiment. Specialization is becoming the norm. Subsystems are becoming very large and complex, requiring a great deal of experience and training for technicians to become qualified maintenance/operation personnel. Formal in-house and off-site programs supplement on-the-job training to fulfill the qualification criteria. This paper presents the Tandem Mirror Experiment-Upgrade (TMX-U) approach to manpower staffing, some problems encountered, possible improvements, and safety considerations for the successful operation of a large experimental facility.
Date: December 1, 1983
Creator: Mattson, G.E.
System: The UNT Digital Library
Catalytic steam gasification of bagasse for the production of methanol (open access)

Catalytic steam gasification of bagasse for the production of methanol

Pacific Northwest Laboratory (PNL) tested the catalytic gasification of bagasse for the production of methanol synthesis gas. The process uses steam, indirect heat, and a catalyst to produce synthesis gas in one step in fluidized bed gasifier. Both laboratory and process development scale (nominal 1 ton/day) gasifiers were used to test two different catalyst systems: (1) supported nickel catalysts and (2) alkali carbonates doped on the bagasse. This paper presents the results of laboratory and process development unit gasification tests and includes an economic evaluation of the process. 20 references, 6 figures, 9 tables.
Date: December 1, 1983
Creator: Baker, E.G. & Brown, M.D.
System: The UNT Digital Library
Transverse spin observables in chromodynamics (open access)

Transverse spin observables in chromodynamics

Quantum Chromodynamics confronts a harsh series of tests in the attempt to formulate a comprehensive approach to the calculation of transverse spin observables. The basic obstacles to understanding transverse spin can be illustrated by considering the transverse structure function g{sub T}(x, Q{sup 2}) = g{sub 1}(x, Q{sup 2}) + g{sub 2}(x, Q{sup 2}), extracted from deep-inelastic scattering using a polarized lepton and a polarized proton. The inadequacy of the transverse-spin basis for quarks and gluons found there suggests a new approach to the problems of single-spin observables in large-transverse-momentum processes. This approach, presented earlier for single spin production asymmetries, is discussed here. It is shown that the mechanism can also lead to baryon polarization effects at large P{sub T}. 14 refs.
Date: December 1, 1989
Creator: Sivers, D.
System: The UNT Digital Library
Performance of a coincidence based blood activity monitor (open access)

Performance of a coincidence based blood activity monitor

A new device has been constructed that measures the positron emitting radio-tracer concentration in arterial blood by extracting blood with a peristaltic pump, then measuring the activity concentration by detecting coincident pairs of 511 keV photons with a pair of heavy inorganic scintillators attached to photomultiplier tubes. The sensitivity of this device is experimentally determined to be 610 counts/second per {mu}Ci/ml, and has a paralyzing dead time of 1.2 {mu}s, so is capable of measuring blood activity concentration as high as 1 mCi/ml. Its performance is compared to two other blood monitoring methods: discrete blood samples counted with a well counter and device that uses a plastic scintillator to directly detect positrons. The positron detection efficiency of this device for {sup 18}F is greater than the plastic scintillation counter, and also eliminates the radioisotope dependent correction factors necessary to convert count rate to absolute concentration. Coincident photon detection also has the potential of reducing the background compared to direct positron detection, thereby increasing the minimum detectable isotope concentration. 10 refs., 6 figs.
Date: December 1, 1989
Creator: Moses, W. W.
System: The UNT Digital Library
Proceedings of the Fifth Annual Participants' Information Meeting: DOE Low-Level Waste Management Program (open access)

Proceedings of the Fifth Annual Participants' Information Meeting: DOE Low-Level Waste Management Program

The meeting consisted of the following six sessions: (1) plenary session I; (2) disposal technology; (3) characteristics and treatment of low-level waste; (4) environmental aspects and performance prediction; (5) overall summary sessions; and (6) plenary session II. Fifty two papers of the papers presented were processed for inclusion in the Energy Data Base. (ATT)
Date: December 1, 1983
Creator: unknown
System: The UNT Digital Library
Quarks and gluons in hadrons and nuclei (open access)

Quarks and gluons in hadrons and nuclei

These lectures discuss the particle-nuclear interface -- a general introduction to the ideas and application of colored quarks in nuclear physics, color, the Pauli principle, and spin flavor correlations -- this lecture shows how the magnetic moments of hadrons relate to the underlying color degree of freedom, and the proton's spin -- a quark model perspective. This lecture reviews recent excitement which has led some to claim that in deep inelastic polarized lepton scattering very little of the spin of a polarized proton is due to its quarks. This lecture discusses the distribution functions of quarks and gluons in nucleons and nuclei, and how knowledge of these is necessary before some quark-gluon plasma searches can be analyzed. 56 refs., 2 figs.
Date: December 1, 1989
Creator: Close, F. E.
System: The UNT Digital Library
Measurement of B sup 0 -- B sup 0 Mixing Using the MARK II at PEP (open access)

Measurement of B sup 0 -- B sup 0 Mixing Using the MARK II at PEP

B{sup 0}{bar B}{sup 0} mixing has been observed now by several experiments. The signature is the observation of an excess of same-sign dilepton events in datasets containing semileptonic B decays. Several years ago the MARK II published an upper limit on B{sup 0}{bar B}{sup 0} mixing at E{sub cm} = 29 GeV, using data taken at the e{sup +}e{sup {minus}} storage ring PEP. Here we report on the results of a new analysis with increased statistics, using refined methods with better sensitivity and control of systematic effects. 10 refs., 2 figs., 2 tab.
Date: December 1, 1989
Creator: Porter, F.
System: The UNT Digital Library
Tracking with wire chambers at high luminosities (open access)

Tracking with wire chambers at high luminosities

Radiation damage and rate limitations impose severe constraints on wire chambers at the SSC. Possible conceptual designs for wire chamber tracking systems that satisfy these constraints are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 11 refs., 10 figs.
Date: December 1, 1989
Creator: Hanson, G. G.
System: The UNT Digital Library
Ion cyclotron radio frequency systems and performance on the tandem mirror experiment-upgrade (TMX-U) (open access)

Ion cyclotron radio frequency systems and performance on the tandem mirror experiment-upgrade (TMX-U)

High power ion cyclotron radio frequency (ICRF) systems are now gaining greater attention than before as prime driver ion heating systems. Lawrence Livermore National Laboratory (LLNL) has installed a 200 kW high frequency (HF) transmitter system on its Tandem Mirror Experiment-Upgrade (TMX-U). This paper describes the system, antenna, controls, and monitoring apparatus. The transmitter operates into a high Q antenna installed in the central cell region of the experiment. It incorporates a dual-port feedback system to automatically adjust the transmitter's output power and allow the maximum consistent with the plasma loading of the antenna. Special techniques have been used to measure, in real-time, the dynamically changing loading values presented by the plasma. From the measurements, the antenna impedance can be optimized for specified plasma density.
Date: December 1, 1983
Creator: Moore, T. L.; Molvik, A. W.; Cummins, W. F.; Pedrotti, L. R.; Henderson, A. L.; Karsner, P. G. et al.
System: The UNT Digital Library
Heavy ion drivers for inertial confinement fusion (open access)

Heavy ion drivers for inertial confinement fusion

The advantages of heavy ion beams as a way of delivering the needed energy and power to an inertial fusion target are surveyed. The existing broad technology base of particle accelerators provides an important foundation for designing, costing, and evaluating proposed systems. The sequence of steps needed for the verification of the heavy ion approach is described; recent research results are even more encouraging than had been assumed hitherto.
Date: December 1, 1983
Creator: Keefe, D.
System: The UNT Digital Library
Portable software for distributed readout controllers and event builders in FASTBUS and VME (open access)

Portable software for distributed readout controllers and event builders in FASTBUS and VME

We report on software developed as part of the PAN-DA system to support the functions of front end readout controllers and event builders in multiprocessor, multilevel, distributed data acquisition systems. For the next generation data acquisition system we have undertaken to design and implement software tools that are easily transportable to new modules. The first implementation of this software is for Motorola 68K series processor boards in FASTBUS and VME and will be used in the Fermilab accelerator run at the beginning of 1990. We use a Real Time Kernel Operating System. The software provides general connectivity tools for control, diagnosis and monitoring. 17 refs., 7 figs.
Date: December 1, 1989
Creator: Pordes, R.; Berg, D.; Berman, E.; Bernett, M.; Brown, D.; Constanta-Fanourakis, P. et al.
System: The UNT Digital Library
The Mark II Silicon Strip Vertex Detector and performance of a silicon detector telescope in the Mark II detector at the SLC (open access)

The Mark II Silicon Strip Vertex Detector and performance of a silicon detector telescope in the Mark II detector at the SLC

A Silicon Strip Vertex Detector (SSVD) consisting of 36 independent silicon detector modules has been built for use in the Mark II detector at the SLAC Linear Collider (SLC). We discuss the performance of the individual modules and the stability and accuracy of their placement in the mechanical support. To gain operational experience at the SLC, we have assembled and placed inside the Mark II a telescope made of three Silicon Detector Modules. We present results from the first data run of the SLC on the overall performance of the Telescope, including backgrounds, charged particle tracking and spatial resolution. 7 refs., 10 figs.
Date: December 1, 1989
Creator: Labarga, L.; Adolphsen, C.; Gratta, G.; Litke, A.; Turala, M.; Zaccardelli, C. (California Univ., Santa Cruz, CA (USA). Inst. for Particle Physics) et al.
System: The UNT Digital Library
B physics theory (open access)

B physics theory

The status of the theoretical predictions for loop decays, strategy for precise determination of Vub and the issue of symmetric versus asymmetric machine for a B factory were discussed in the working group. While from our present perspective observation of CP violation appears as the most prominent goal for a B factory, the importance and richness of other B physics was stressed. 23 refs.
Date: December 1, 1989
Creator: Soni, A. (Brookhaven National Lab., Upton, NY (USA). Physics Dept.)
System: The UNT Digital Library
Properties of leptons (open access)

Properties of leptons

The properties of the electron, muon, tau, and their neutrinos are reviewed. Three discrepancies in our understanding of those properties are discussed: the lifetime of orthopositronium, the mass spectra of e{sup +}e{sup -} pairs produced in heavy ion collisions, and the 1-charged particle modes problem in tau decays. The review concludes with a discussion of what we need to learn about the tau and the consequent need for a tau-charm factory. 68 refs., 7 figs., 8 tabs.
Date: December 1, 1989
Creator: Perl, Martin L.
System: The UNT Digital Library
Cosmology and the weak interaction (open access)

Cosmology and the weak interaction

The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N{sub {nu}} {approximately} 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs.
Date: December 1, 1989
Creator: Schramm, D. N.
System: The UNT Digital Library
Microwave measurement test results of circular waveguide components for electron cyclotron resonant heating (ECRH) of the Tandem Mirror Experiment-Upgrade (TMX-U) (open access)

Microwave measurement test results of circular waveguide components for electron cyclotron resonant heating (ECRH) of the Tandem Mirror Experiment-Upgrade (TMX-U)

Development of high-power components for electron cyclotron resonant heating (ECRH) applications requires extensive testing. In this paper we describe the high-power testing of various circular waveguide components designed for application on the Tandem Mirror Experiment-Upgrade (TMX-U). These include a 2.5-in. vacuum valve, polarizing reflectors, directional couplers, mode converters, and flexible waveguides. All of these components were tested to 200 kW power level with 40-ms pulses. Cold tests were used to determine field distribution. The techniques used in these tests are illustrated. The new high-power test facility at Lawrence Livermore National Laboratory (LLNL) is described and test procedures are discussed. We discuss the following test results: efficiency at high power of mode converters, comparison of high power vs low power for waveguide components, and full power tests of the waveguide system. We also explain the reasons behind selection of these systems for use on TMX-U.
Date: December 1, 1983
Creator: Williams, C.W.; Rubert, R.R.; Coffield, F.E.; Felker, B.; Stallard, B.W. & Taska, J.
System: The UNT Digital Library
Strangeonia and kin; new results from kaon hadroproduction with LASS (open access)

Strangeonia and kin; new results from kaon hadroproduction with LASS

Recent results from a high statistics study of strangeonium mesons produced in LASS by an 11 GeV/c K{sup -} beam are reviewed and compared with the quark model. New data from a variety of final states (K*{ovr K*}, {phi}{phi}, {phi}{pi}{sup 0}) produced by hypercharge exchange are described, and compared with results from other hadroproduction modes and from J/{psi} decay. 17 refs., 12 figs.
Date: December 1, 1989
Creator: Aston, D.; Bienz, T.; Bird, F.; Dunwoodie, W.; Johnson, W.B.; Kunz, P. et al.
System: The UNT Digital Library
CP violation (open access)

CP violation

Predictions for CP violation in the three generation Standard Model are reviewed based on what is known about the Cabibbo-Kobayashi-Maskawa matrix. Application to the K and B meson systems are emphasized. 43 refs., 13 figs.
Date: December 1, 1989
Creator: Gilman, Frederick J.
System: The UNT Digital Library
High performance, suppressed-fission ICF hybrid (open access)

High performance, suppressed-fission ICF hybrid

The neutronics aspects of an ICF hybrid concept are discussed. The breeding blanket consists of a beryllium neutron multiplier, metallic thorium fertile fuel and a liquid-lithium coolant. The fertile fuel fraction is 30 vol%, which is much higher than previous one-zone, suppressed-fission hybrid concepts. Fission in the bred /sup 233/U is suppressed by competition from tritium breeding reactions in /sup 6/Li. The total breeding ratio, T + F, is 2.05, and the total neutron energy deposited is 41.1 MeV per DT neutron. The 800-MW (fusion) hybrid produces approx. 3500 kg of /sup 233/U per full-power-year.
Date: December 1, 1983
Creator: Meier, W. R.
System: The UNT Digital Library
Spontaneous breaking of supersymmetry (open access)

Spontaneous breaking of supersymmetry

There has been recently a revival of interest in supersymmetric gauge theories, stimulated by the hope that supersymmetry might help in clarifying some of the questions which remain unanswered in the so called Grand Unified Theories and in particular the gauge hierarchy problem. In a Grand Unified Theory one has two widely different mass scales: the unification mass M approx. = 10/sup 15/GeV at which the unification group (e.g. SU(5)) breaks down to SU(3) x SU(2) x U(1) and the mass ..mu.. approx. = 100 GeV at which SU(2) x U(1) is broken down to the U(1) of electromagnetism. There is at present no theoretical understanding of the extreme smallness of the ratio ..mu../M of these two numbers. This is the gauge hierarchy problem. This lecture attempts to review the various mechanisms for spontaneous supersymmetry breaking in gauge theories. Most of the discussions are concerned with the tree approximation, but what is presently known about radiative correction is also reviewed.
Date: December 1, 1981
Creator: Zumino, B.
System: The UNT Digital Library
Digital neutron radiography using plane converters with multiwire proportional chambers (open access)

Digital neutron radiography using plane converters with multiwire proportional chambers

The work described here was completed more than three years ago, and represents, in large part the PhD and MS thesis research of two of the present authors. Much of it has been reported previously elsewhere. It constitutes an effort to develop and study a moderately low cost, moderate resolution, high sensitivity, on-line method for digital neutron radiography, intended for use where neutron fluence was limited by source strength, or received dose. The basic imaging system consisted of a position-sensitive gas proportional chamber together with its associated imaging electronics, and a plane neutron converter. Enriched-boron, gadolinium, and polyethylene (for fast neutrons) converters were analyzed and tested. Some work was done on digital data enhancement, and efforts to improve spatial resolution included pressurizing the proportional-chamber gas to reduce the track lengths of the neutron-interaction products.
Date: December 1, 1981
Creator: Kaplan, S. N.; Director, B. A.; Perez-Mendez, V. & Valentine, K. H.
System: The UNT Digital Library
The Collective Vector method in nuclear and atomic physics (open access)

The Collective Vector method in nuclear and atomic physics

We present a brief review of the method of the Collective Vector (CV) and its use in conjunction with the Lanczos algorithm (LA). The combination of these two ideas produces a method for contracting super-large hamiltonians (up to 10{sup 6} {times} 10{sup 6}) by factors of 1000 or more. The contracted hamiltonians, which we call quasi-hamiltonians, typically have dimensions of the order of 10{sup 2} {times} 10{sup 2} and produce corresponding quasi-spectra with associated quasi-eigenfunctions which reproduce the features of the full microscopic spectrum thru the conservation of the spectral moments. Examples of applications to both nuclear and atomic physics are given demonstrating the convergence properties of the method. The application of the LA/CV approach to the problem of modelling nuclear level densities is described and finally we discuss the possibility of conjoining new collective models of nuclear structure with the LA/CV method. 13 refs., 4 figs.
Date: December 1, 1989
Creator: Bloom, S.D.
System: The UNT Digital Library
Cosmions and stars (open access)

Cosmions and stars

Hypothetical particles such as the heavy neutrino, the photino, or the sneutrino/emdash/generically called cosmions/emdash/may solve the so called missing mass problem. If they exist, the cosmions may close the Universe. In addition to their gravitational effect on cosmological scales, the cosmions may also be captured by stars and concentrate in their cores. Since cosmions are able to transport heat outside stellar cores much more efficiently than photons, they may seriously affect the thermodynamics of the inner layer of stars. We have done an exact calculation of the accretion rate of cosmions by main sequence stars and we have studied the suppression of their central convection. We concluded that central convection inside stars between 0.3 Msub solar and 1 Msub solar is broken in the presence of cosmions. 6 refs., 2 figs.
Date: December 1, 1987
Creator: Salati, P.
System: The UNT Digital Library
Fuel systems for compact fast space reactors (open access)

Fuel systems for compact fast space reactors

About 200 refractory metal clad ceramic fuel pins have been irradiated in thermal reactors under the 1200 K to 1550 K cladding temperature conditions of primary relevance to space reactors. This paper reviews performance with respect to fissile atom density, operating temperatures, fuel swelling, fission gas release, fuel-cladding compatibility, and consequences of failure. It was concluded that UO/sub 2/ and UN fuels show approximately equal performance potential and that UC fuel has lesser potential. W/Re alloys have performed quite well as cladding materials, and Ta, Nb, and Mo/Re alloys, in conjunction with W diffusion barriers, show good promise. Significant issues to be addressed in the future include high burnup swelling of UN, effects of UO/sub 2/-Li coolant reaction in the event of fuel pin failure, and development of an irradiation performance data base with prototypically configured fuel pins irradiated in a fast neutron flux.
Date: December 1, 1983
Creator: Cox, C.M.; Dutt, D.S. & Karnesky, R.A.
System: The UNT Digital Library