Resource Type

Degree Department

2,468 Matching Results

Results open in a new window/tab.

Computation of self-consistent 2-D MHD with neutral-beam and bootstrap currents in elongated plasmas (open access)

Computation of self-consistent 2-D MHD with neutral-beam and bootstrap currents in elongated plasmas

The observation of substantial current drive from neutral beam injection (NBI) in TFTR, JET and DIII-D has led to renewed interest in a steady state, non-inductively driven tokamak. The discovery of apparently considerable neoclassical (bootstrap) current in TFTR, makes a steady state device even more attractive since the bootstrap portion of the current could be obtained without additional power input. Motivated by these results, we have developed a code, ACCOME, which self-consistently computes the 2-D MHD equilibrium with the current driven by neutral beams, bootstrap and the electric field. In this paper we first describe some details of the code in the next section and in the subsequent section show some applications to DIII-D and to a possible ITER design.
Date: April 5, 1983
Creator: Devoto, R. S.; Tani, K. & Azumi, M.
System: The UNT Digital Library
Proceedings of the flat-plate solar array project research forum on photovoltaic metallization systems (open access)

Proceedings of the flat-plate solar array project research forum on photovoltaic metallization systems

A Photovoltaic Metallization Research Forum, under the sponsorship of the Jet Propulsion Laboratory's Flat-Plate Solar Array Project and the US Department of Energy, was held March 16-18, 1983 at Pine Mountain, Georgia. The Forum consisted of five sessions, covering (1) the current status of metallization systems, (2) system design, (3) thick-film metallization, (4) advanced techniques and (5) future metallization challenges. Twenty-three papers were presented.
Date: November 15, 1983
Creator: unknown
System: The UNT Digital Library
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
Drug metabolizing enzyme systems and their relationship to toxic mechanisms (open access)

Drug metabolizing enzyme systems and their relationship to toxic mechanisms

The metabolism and toxicity of 3-methylfuran (3-MF) are described. The major product of metabolic activation of 3-MF appears to be disemicarbazones. Cursory description of toxic effects of 3-MF on lung and kidneys are provided. 18 refs.
Date: January 1, 1983
Creator: Boyd, M. R.; Ravindranath, V.; Burka, L. T.; Dutcher, J. S.; Franklin, R. B.; Statham, C. N. et al.
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
Formation of H/sup -/ by charge transfer in alkaline-earth vapors (open access)

Formation of H/sup -/ by charge transfer in alkaline-earth vapors

Progress since the last symposium on the study of H/sup -/ formation by charge transfer in alkaline-earth vapors is reported. High yields are obtained at low energies, in agreement with theoretical predictions.
Date: December 5, 1983
Creator: Schlachter, A.S. & Morgan, T.J.
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
Data needs for the track structure of alpha particles and electrons in water (open access)

Data needs for the track structure of alpha particles and electrons in water

We have made calculations of the ionization spectra for alpha particle and electron tracks in water. We have also computed the number of ions created per micrometre of track length, the energy distribution of the secondaries, and the energy expended per ion pair created. Our aim is less toward theoretical derivations than to obtain a numerically accurate description of the track structure at all energies in a form suitable for biomedical applications. 13 references.
Date: January 1, 1983
Creator: Pagnamenta, A.
System: The UNT Digital Library
Variational methods in steady state diffusion problems (open access)

Variational methods in steady state diffusion problems

Classical variational techniques are used to obtain accurate solutions to the multigroup multiregion one dimensional steady state neutron diffusion equation. Analytic solutions are constructed for benchmark verification. Functionals with cubic trial functions and conservational lagrangian constraints are exhibited and compared with nonconservational functionals with respect to neutron balance and to relative flux and current at interfaces. Excellent agreement of the conservational functionals using cubic trial functions is obtained in comparison with analytic solutions.
Date: January 1, 1983
Creator: Lee, C.E.; Fan, W.C.P. & Bratton, R.L.
System: The UNT Digital Library
Results on nu/sub. mu. /e Elastic Scattering (open access)

Results on nu/sub. mu. /e Elastic Scattering

A measurement of the nu/sub ..mu../e elastic scattering cross section is presented. These data analyzed were run at the Brookhaven AGS wide band neutrino beam ((E/sub nu/) = 1.5 GeV).
Date: January 1, 1983
Creator: Ahrens, L. A.; Aronson, S. H.; Connolly, P. L.; Callas, J. L.; Cutts, D.; Amako, K. et al.
System: The UNT Digital Library
Experience with a saddle field ion source for sputtering (open access)

Experience with a saddle field ion source for sputtering

A discussion is presented concerning the method of setting up a saddle field ion source for sputtering thin films. Preliminary results will be presented for sputtering rates of different materials.
Date: January 1, 1983
Creator: Thomas, G.E.
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
Spiral kicker for the beam abort system (open access)

Spiral kicker for the beam abort system

A brief study was carried out to determine the feasibility of a special kicker to produce a damped spiral beam at the beam dump for the beam abort system. There appears to be no problem with realizing this concept at a reasonably low cost.
Date: January 1, 1983
Creator: Martin, R.L.
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
Ultrafast gated intensifier design for laser fusion x-ray framing applications (open access)

Ultrafast gated intensifier design for laser fusion x-ray framing applications

A major challenge for laser fusion is the study of the symmetry and the hydrodynamic stability of imploding fuel capsules. Streaked x-radiography, in one space and one time dimension, does not provide sufficient information. Two (spatial) dimensional frames of 10 to 100 ps duration are required with good image quality, minimum geometrical distortion (approximately 1%), dynamic range greater than 1000 and greater than 200 x 200 pixels. A gated transmission line imager (TLI) can meet these requirements with frame times between 30 and 100 ps. An instrument of this type is now being developed. Progress on this instrument including theory of operation, ultrafast pulse generation and propagation, component integration, and high resolution phosphor screen development are presented.
Date: November 1, 1983
Creator: Price, R.H.; Wiedwald, J.D.; Kalibjian, R.; Thomas, S.W. & Cook, W.M.
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
Assessment of the response of spent fuel transports to malevolent acts (open access)

Assessment of the response of spent fuel transports to malevolent acts

This paper describes the results of a program conducted at Sandia National Laboratories (SNL) for the US Department of Energy to provide an experimental data base for more accurately assessing the radiological consequences from a hypothetical sabotage attack on a spent fuel shipping cask. The primary objectives of the program were limited to: (1) evaluating the effectiveness of selected high explosive devices (HED) in breaching full-size spent fuel casks, (2) quantifying and characterizing relevant aerosol properties of the released fuel, and (3) using the resulting experimental data to evaluate the radiological health consequences resulting from a hypothetical sabotage attack on a spent fuel shipping cask in a densely populated area. Subscale and full-scale experiments in conjunction with an analytical modeling study were performed to meet the programmatic objectives. The data from this program indicate that the Urban Studies greatly overestimated the impact of malevolent acts directed at spent fuel casks in urban environs. From that standpoint this work could be the basis of additional regulatory revisions of the NRC physical protection requirements. In a larger sense this work can also be the basis of more credible worst case analyses since it defines the actual result of an event which is …
Date: December 20, 1983
Creator: Sandoval, R.P.
System: The UNT Digital Library
Progress in numerical calculations of ion-atom collisions (open access)

Progress in numerical calculations of ion-atom collisions

An ion-atom collision produces a time dependent perturbation of a many fermion system. In this collision, excitation, ionization and charge transfer can occur. The driving mechanism for these processes may be thought of as the potentials seen by individual electrons at any given separation of the projectile and target nuclei. If we think of these potentials as belonging to the target (a nucleus and electrons) and the projectile (another nucleus and electrons) then as detected by an electron the potentials change because: (a) the target and projectile change position, and (b) electrons on the target and projectile change states. Most work in the past fifty years has concentrated on solving the independent particle model (IPM). Cracks are beginning to appear in this model which only allows for type (a) changes in the potential. But in a short review we shall have quite enough to do in understanding the progress made in the last decade on the IPM. This paper is divided into three parts. The first deals with how to reduce the IPM to the single electron model (SEM). The second is on a new method where charge transfer is important. The third confronts some standard models with modern calculations.
Date: January 1, 1983
Creator: Reading, J.F.; Ford, A.L. & Becker, R.L.
System: The UNT Digital Library
Measurements of the deposition rates of radon daughters on indoor surfaces (open access)

Measurements of the deposition rates of radon daughters on indoor surfaces

The deposition rates of radon daughters on indoor surfaces have been measured by exposing the window of a proportional counter to the air of a house with high concentrations of radon and its daughters. Deposition velocities for unattached RaA and RaB of approximately 4 mm sec/sup -1/ were obtained by dividing the deposition rates by the concentrations of unattached daughters in the air. These results agree with those obtained by other workers but are dependent on the assumptions made about the fractions of the daughters which are attached to the atmospheric aerosol.
Date: January 1, 1983
Creator: Toohey, R.E.; Essling, M.A.; Rundo, J. & Hengde, W.
System: The UNT Digital Library
MFTF-B quasi-optical ECRH transmission system (open access)

MFTF-B quasi-optical ECRH transmission system

The microwave transmission system for ERCH on MFTF-B will utilize quasi-optical transmission techniques. The system consists of ten gyrotron oscillators: two gyrotrons at 28 GHz, two at 35 GHz, and six at 56 GHz. The 28 and 35 GHz gyrotrons both heat the electrons in the end plug (potential peak) while the 56 GHz sources heat the minimum-B anchor region (potential minimum). Microwaves are launched into a pair of cylindrical mirrors that form a pseudo-cavity which directs the microwaves through the plasma numerous times before they are lost out of the cavity. The cavity allows the microwave beam to reach the resonance zone over a wide range of plasma densities and temperatures. The fundamental electron cyclotron resonance moves to higher axial positions as a result of beta-depression of the magnetic field, doppler shifting of the resonance, and relativistic mass corrections for the electrons. With this system the microwave beam will reach the resonance surface at the correct angle of incidence for any density or temperature without active aiming of the antennas. The cavity also allows the beam to make multiple passes through the plasma to increase the heating efficiency at low temperatures and densities when the single pass absorption is …
Date: November 7, 1983
Creator: Yugo, J. J.; Shearer, J. W. & Ziolkowski, R. W.
System: The UNT Digital Library
Comparative analysis of internal fuel motion in annular fuel designs (open access)

Comparative analysis of internal fuel motion in annular fuel designs

In this paper, the whole-core reactivity consequences of internal fuel motion in three annular fuel designs during a hypothetical 3 dollars/s transient overpower (TOP) accident are compared to determine the effect of geometric design variations. The PINEX-2 and PINEX-3 experiments were performed in the TREAT reactor using annular fuel pins irradiated in GETR. This paper investigates three combinations of solid and annular axial blankets and fission gas plena: top annular blanket and plenum, bottom annular blanket and plenum, and both top and bottom (dual) annular blankets and plena. The dual plena design case showed a significant decrease in internal fuel motion over the single plenum design cases.
Date: September 16, 1983
Creator: Smith, D. E.
System: The UNT Digital Library
Superconducting (radiation hardened) magnets for mirror fusion devices (open access)

Superconducting (radiation hardened) magnets for mirror fusion devices

Superconducting magnets for mirror fusion have evolved considerably since the Baseball II magnet in 1970. Recently, the Mirror Fusion Test Facility (MFTF-B) yin-yang has been tested to a full field of 7.7 T with radial dimensions representative of a full scale reactor. Now the emphasis has turned to the manufacture of very high field solenoids (choke coils) that are placed between the tandem mirror central cell and the yin-yang anchor-plug set. For MFTF-B the choke coil field reaches 12 T, while in future devices like the MFTF-Upgrade, Fusion Power Demonstration and Mirror Advanced Reactor Study (MARS) reactor the fields are doubled. Besides developing high fields, the magnets must be radiation hardened. Otherwise, thick neutron shields increase the magnet size to an unacceptable weight and cost. Neutron fluences in superconducting magnets must be increased by an order of magnitude or more. Insulators must withstand 10/sup 10/ to 10/sup 11/ rads, while magnet stability must be retained after the copper has been exposed to fluence above 10/sup 19/ neutrons/cm/sup 2/.
Date: December 7, 1983
Creator: Henning, C. D.; Dalder, E. N. C.; Miller, J. R. & Perkins, J. R.
System: The UNT Digital Library
Effects of nominal and crack-tip strain rate on IGSCC susceptibility in CERT tests (open access)

Effects of nominal and crack-tip strain rate on IGSCC susceptibility in CERT tests

Constant extension rate tests have been performed on sensitized Type 316 stainless steel in oxygenated water (8 ppM O/sub 2/) containing chloride ion impurities (0.5 ppM) over a range of strain rates from 10/sup -5/ to 2 x 10/sup -7/ s/sup -1/. The susceptibility to IGSCC (as quantified by parameters such as crack length at failure) increases with a decrease in strain rate. A model consistent with the observed and postulated crack growth behavior and with a fracture criterion is presented and used to derive power laws that relate the IGSCC susceptibility parameters and strain rate. The predicted strain rate exponents are in agreement with the experimental results of this and other studies. The correlations between IGSCC susceptibility and strain rate can be used to predict susceptibility to cracking outside the range of conditions used in the laboratory. In addition, it is shown that the average crack-tip strain rate in CERT experiments can be estimated by use of a J-integral approach. It is observed that the average crack growth rate is proportional to the square root of the estimated average crack-tip strain rate. The experimentally observed correlation is in good agreement with that deduced from a slip-dissolution model proposed by …
Date: September 1, 1983
Creator: Maiya, P.S. & Shack, W.J.
System: The UNT Digital Library