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Enhancement of DIII-D neutral beam system for higher performance
The DIII-D tokamak employs eight neutral beam systems for plasma heating and current drive experiments. These positive ion source neutral beam systems have gone through several improvements in operational technique and in system hardware since the start of conditioning of the first long pulse ion source in December 1986. These improvements have led to the routine operation in deuterium at beam power levels of 20 MW. The improvements in operational technique include filament power supply operating mode, accelerator grid voltage holding capability, mid changes in grid potential gradients. The hardware improvements include installation of arc notching, arc discharge density regulation, and control of neutralizer gas puffing. Each of these improvements are discussed in this paper. Successful testing and operation of the ion source at 93 kV deuterium beam energy, well above the design value of 80 kV, also led to the possibility of enhancing system capability to 28 MW power level, nearly twice the original design value. Upgrading of the beam system to 60 second pulse duration at the currently achieved power level is under consideration. Studies have shown that this pulse length extension can be achieved with improvements in beamline heat handling components and auxiliary systems, especially the power …
Date:
September 1, 1992
Creator:
Hong, R.; Colleraine, A. P.; Kellman, D. H.; Kim, J.; Luxon, J. L.; Nerem, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Evaluation of S-101 course Supervisors Orientation to Occupational Safety Compliance in DOE'' taught in Upton, New York, July 14--17, 1992
This report summarizes trainee evaluations for the Safety Training Section course, Supervisors' Orientation to Occupational Safety in DOE,'' (S101) which was conducted July 14--17 at Brookhaven National Laboratory, in Upton, New York. Sections 1.1 and 1.2 summarize the quantitative course evaluations that trainees provided upon completion of the course. Appendix A provides a transcript of the trainees' written comments. Numeric course ratings were generally positive and show that the course material and instruction were very effective. Written comments supported the positive numeric ratings. The course content and knowledge gained by the trainees exceeded most of the students' expectations of the course. Results from the final examination showed that students gained significant knowledge from the course.
Date:
September 1, 1992
Creator:
Wright, T S
Object Type:
Report
System:
The UNT Digital Library
Combustion, pyrolysis, gasification, and liquefaction of biomass
All the products now obtained from oil can be provided by thermal conversion of the solid fuels biomass and coal. As a feedstock, biomass has many advantages over coal and has the potential to supply up to 20% of US energy by the year 2000 and significant amounts of energy for other countries. However, it is imperative that in producing biomass for energy we practice careful land use. Combustion is the simplest method of producing heat from biomass, using either the traditional fixed-bed combustion on a grate or the fluidized-bed and suspended combustion techniques now being developed. Pyrolysis of biomass is a particularly attractive process if all three products - gas, wood tars, and charcoal - can be used. Gasification of biomass with air is perhaps the most flexible and best-developed process for conversion of biomass to fuel today, yielding a low energy gas that can be burned in existing gas/oil boilers or in engines. Oxygen gasification yields a gas with higher energy content that can be used in pipelines or to fire turbines. In addition, this gas can be used for producing methanol, ammonia, or gasoline by indirect liquefaction. Fast pyrolysis of biomass produces a gas rich in ethylene …
Date:
September 1980
Creator:
Reed, T. B.
Object Type:
Article
System:
The UNT Digital Library
Application of uncertainty analysis of ignition performance to the Engineering Test Reactor
The design of future Engineering Test Reactor (ETR) to demonstrate ignition is complicated by the uncertainties in the projected database for ignited plasmas. Application of uncertainty analysis to ETR design utilizing a figure-of-merit defined as the probability of ignition is presented. Performance evaluation from the uncertainty analysis in density-temperature space can locate an optimum operating window for ignition. 11 refs., 5 figs., 3 tabs.
Date:
September 16, 1988
Creator:
Ho, S. K. & Perkins, L. J.
Object Type:
Article
System:
The UNT Digital Library
High beta and second stability region transport and stability analysis
This report describes ideal and resistive studies of high-beta plasmas and of the second stability region. Emphasis is focused on supershot'' plasmas in TFIR where MHD instabilities are frequently observed and which spoil their confinement properties. Substantial results are described from the analysis of these high beta poloidal plasmas. During these studies, initial pressure and safety factor profiles were obtained from the TRANSP code, which is used extensively to analyze experimental data. Resistive MBD stability studies of supershot equilibria show that finite pressure stabilization of tearing modes is very strong in these high {beta}p plasmas. This has prompted a detailed re-examination of linear tearing mode theory in which we participated in collaboration with Columbia University and General Atomics. This finite pressure effect is shown to be highly sensitive to small scale details of the pressure profile. Even when an ad hoc method of removing this stabilizing mechanism is implemented, however, it is shown that there is only superficial agreement between resistive MBD stability computation and the experimental data. While the mode structures observed experimentally can be found computationally, there is no convincing correlation with the experimental observations when the computed results are compared with a large set of supershot data. …
Date:
September 1, 1992
Creator:
Hughes, M. H.; Phillps, M. W.; Todd, A. M. M.; Krishnaswami, J. & Hartley, R.
Object Type:
Report
System:
The UNT Digital Library
FAD: A full-acceptance detector for physics at the SSC
For high energy pp collisions, the concepts 4{pi}'' and full acceptance'' are distinct. At the SSC, the appropriate variables for describing phase space are the lego variables: pseudorapidity {eta} and azimuthal angle {phi}. While most of 4{pi} is covered by pseudorapidities less than 3 or 4 in magnitude, at the SSC there is very interesting physics out to {eta}'s of 9 to 12. For over a year I have been attempting to encourage an initiative at the SSC to provide a detector which could cover the missing acceptance of the two big detectors, which in particular have no appreciable charged particle tracking with good momentum resolution beyond rapidities of 2.5 or so. The nonnegotiable criteria for an FAD are for me the following: 1. All charged particles are seen and their momenta measured well, provided pt is not too large. 2. All photons are seen and their momenta are measured well. 3. The physics of rapidity-gaps is not compromised. This means angular coverage from 90{degrees} down to tens of microradians. The above criteria cannot be met on day one of SSC commissioning with the amount of funds available. But I believe a staged approach is feasible, with a lot of …
Date:
September 1, 1992
Creator:
Bjorken, J. D.
Object Type:
Article
System:
The UNT Digital Library
Multiple-gap theory of toroidal Alfven waves with kinetic effects
The stability of kinetic toroidal Alfven waves with multi-gap coupling is analyzed by using the two-dimensional ballooning transform. An alternate convergence scheme, based on the smallness of the inverse aspect ratio, is devised. The resulting wave functions are oscillatory and do not balloon in contrast to the wave functions of conventional ballooning theory. It is shown that the single-gap theory is a special, weak shear (s {yields} 0) limit of the formalism. Analytical and numerical results for the two fundamental branches, the ideal toroidal Alfven eigenmode (TAE), and the kinetic toroidal Alfven eigenmode (KTAE) are presented and discussed.
Date:
September 1, 1992
Creator:
Zhang, X. D.; Zhang, Y. Z. & Mahajan, S. M.
Object Type:
Report
System:
The UNT Digital Library
Wintertime meteorology of the Grand Canyon region
The Grand Canyon region of the American Southwest is an interesting region meteorologically, but because of its isolated location, the lack of major population centers in the region, and the high cost of meteorological field experiments, it has historically received little observational attention. In recent years, however, attention has been directed to episodes of visibility degradation in many of the US National parks, and two recent field studies focused on this visibility problem have greatly increased the meteorological data available for the Grand Canyon region. The most recent and comprehensive of these studies is the Navajo Generating Station Winter Visibility Study of 1989--90. This study investigated the sources of visibility degradation in Grand Canyon National Park and the meteorological mechanisms leading to low visibility episodes. In this paper we present analyses of this rich data set to gain a better understanding of the key wintertime meteorological features of the Grand Canyon region.
Date:
September 1, 1992
Creator:
Whiteman, C. D.
Object Type:
Article
System:
The UNT Digital Library
Proceedings of the workshop on measurement of heavy elements in vivo. [Lead]
Separate abstracts were prepared for 22 papers that discuss methods for the external measurement of transuranium elements deposited in personnel.
Date:
September 1, 1976
Creator:
Swinth, K. L. (ed.)
Object Type:
Article
System:
The UNT Digital Library
Instrumentation for measuring soft x-rays from laser produced plasmas
Instrumentation has been developed at the Lawrence Livermore Laboratory for measuring subkilovolt x-rays from laser-produced plasmas. This information is needed to do a complete energy balance on laser fusion experiments. The instruments must have thin windows and yet discriminate against the severe environment of other intense target emissions such as ions, electrons, and scattered laser light. Low energy x-ray measurements down to 0.1 keV will be presented using these absolutely calibrated detectors on laser target shots with the LLL Terawatt laser facility, Cyclops. Precautions in using these detectors in a laser fusion target chamber will be enumerated from our experience in using these instruments on hundreds of laser shots.
Date:
September 24, 1976
Creator:
Slivinsky, V. W.; Ahlstrom, H. G.; Kornblum, H. N.; Koppel, L. N. & Leipelt, G. R.
Object Type:
Article
System:
The UNT Digital Library
Fusion reactor wastes
The potential waste releases for commercial fusion power plants were estimated by use of standard environmental analysis procedures incorporating a high degree of speculation. The analytical procedure is presented. A description was obtained for each of the ten fusion power plant concepts currently being developed. These concepts were then analyzed to determine the general characteristics and probable waste releases. (MOW)
Date:
September 1, 1976
Creator:
Young, J R
Object Type:
Article
System:
The UNT Digital Library
Ultrasonic measurement of elastic constants at temperatures from 20 to 1100/sup 0/C. [LMFBR and HTGR materials]
Measurements of the elastic moduli at temperatures from 20 to 1100/sup 0/C of a number of materials of interest in the Liquid Metal Fast Breeder Reactor and the High Temperature Gas Reactor were accomplished using acoustic techniques. A two-step process was required to complete the measurements. First, the acoustic velocities were measured accurately on bulk samples at room temperature, then a wire sample was used to make elevated-temperature measurements. A computer was used to calculate the moduli and plot the data. A detailed summary has been made of the sources of error and a calculation of the precision of the measurements is given.
Date:
September 1, 1976
Creator:
Moyer, M. W. & Hammond, J. P.
Object Type:
Report
System:
The UNT Digital Library
Energy and technology review
Separate abstracts were prepared for each of the three reports in this issue. In addition, it contains very brief news items on improved neutron yields in the laser program and a new global ozone monitor. (RWR)
Date:
September 1, 1976
Creator:
Selden, R. W.; Crawford, R. B.; Cummings, K. L.; McCaleb, C. S. & Prono, J. K. (eds.)
Object Type:
Report
System:
The UNT Digital Library
Particle acceleration by collective effects
Successful acceleration of protons and other ions has been achieved experimentally in this decade by a number of different collective methods. The attainment of very high accelerating fields has been established although so far the acceleration distance has been confined to only a few centimeters. Efforts are in progress to understand the accelerating mechanisms in detail and, as a result, to devise ways of extending considerably the acceleration distance. A review is given of the current progress, expectations, and limitations of the different approaches.
Date:
September 1, 1976
Creator:
Keefe, D.
Object Type:
Report
System:
The UNT Digital Library
Simulation of fluid-rock interactions in a geothermal basin. Final report. [QUAGMR (quasi-active geothermal reservoir)]
General balance laws and constitutive relations are developed for convective hydrothermal geothermal reservoirs. A fully interacting rock-fluid system is considered; typical rock-fluid interactions involve momentum and energy transfer and the dependence of rock porosity and permeability upon the fluid and rock stresses. The mathematical model also includes multiphase (water/steam) effects. A simple analytical model is employed to study heat transfer into/or from a fluid moving in a porous medium. Numerical results show that for fluid velocities typical of geothermal systems (Reynolds number much less than 10), the fluid and the solid may be assumed to be in local thermal equilibrium. Mathematical formalism of Anderson and Jackson is utilized to derive a continuum species transport equation for flow in porous media; this method allows one to delineate, in a rigorous manner, the convective and diffusive mechanisms in the continuum representation of species transport. An existing computer program (QUAGMR) is applied to study upwelling of hot water from depth along a fault; the numerical results can be used to explain local temperature inversions occasionally observed in bore hole measurements.
Date:
September 1, 1975
Creator:
Garg, S. K.; Blake, T. R.; Brownell, D. H. Jr.; Nayfeh, A. H. & Pritchett, J. W.
Object Type:
Report
System:
The UNT Digital Library
Effect of ground motion from nuclear excavation: interim canal studies
The effect of ground motion due to nuclear excavation of a sea-level canal at two alternative routes, 17A and 25E, are discussed from the aspects of motion prediction and structural response. The importance of the high-rise building problem is stressed because of its complexity. Several damage criteria are summarized for advance planning of excavation and operation. The 1964 shot schedule and the latest revised schedule are included for comparison.
Date:
September 1, 1969
Creator:
King, C. Y. & Nadolski, M. E.
Object Type:
Report
System:
The UNT Digital Library
Selection and evaluation of thermal criteria for a geologic waste isolation facility in salt
Previous design efforts for geologic waste isolation facilities in bedded salt developed several limiting temperature conditions, or thermal criteria, for use in parametric studies. These criteria, along with other design parameters, must assure that the temperature variations that occur do not adversely affect operating personnel and equipment during normal operations as well as assure containment and environmental integrity. The goals of the present study are to review past analyses of thermal criteria, determine the factors that should be considered in defining thermal criteria, suggest appropriate procedures for determining thermal criteria and suggest additional experimental and computational efforts required to adequately determine thermal criteria. The approach taken was to divide consideration of the system into four categories of thermal effects and four phases of facility operation. The categories were effects on the canister and its immediate environs, effects on the operating environment experienced by personnel and equipment, effects on storage room integrity, and effects on the biosphere. The phases of facility operation were loading, storage, retrieval, and disposal. Each of the categories was further subdivided into several aspects for detailed consideration of thermal effects through the four operating phases. This comprehensive approach was taken to ensure that all conceivable thermal effects …
Date:
September 1, 1976
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Intertechnology Corporation proposed test and evaluation plan, commercial buildings. National Solar Demonstration Program
This report has three major parts. The first of these derives the requirements for the Test and Evaluation plan from the System Level Plan which is summarized in Section II. The second part contains the proposed plan to fill these requirements and includes hardware and software recommendations as well as procedures and management considerations. Primary emphasis has been given to the remote site because this is the area in which the commercial part of the demonstration is most unique. Finally, some pre-demonstration activities are described. The pilot program is intended to resolve a number of issues which arose in the course of the T and E plan. These relate to choice of scan frequencies, compression algorithms, etc. It is also intended to confirm performance and cost effectiveness of the site data collection package. The base line measurements of attitudes, etc. provide a reference mark against which one can measure the non-technical effectiveness of the demonstration program. (WDM)
Date:
September 1, 1976
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Silicone elastomer evaluation for cable jacket application. Final report
A silicone elastomer manufactured by General Electric's Silicone Products Division was found to be adequate for use as a cable jacket compound. The elastomer has room temperature physical properties approximately equal to those of the currently used neoprene jacket compound and permits functional operations at temperatures both above and below those of neoprene.
Date:
September 1, 1976
Creator:
Crockett, R. R.
Object Type:
Report
System:
The UNT Digital Library
Effect of machining damage on tensile properties of beryllium
It is well established that damage introduced at the surface of beryllium during machining operations can lower its mechanical properties. Tensile tests were conducted to illustrate this on beryllium presently being used for parts in the W79 program and similar to the new powder-processed beryllium specified for production (tentative specification MEL 76-001319). The objective of this study is to quantitatively illuminate the importance of controlling machining damage in this particular grade of powder-processed beryllium.
Date:
September 20, 1976
Creator:
Hanafee, J. E.
Object Type:
Report
System:
The UNT Digital Library
Thermal response of core and central-cavity components of a high-temperature gas-cooled reactor in the absence of forced convection coolant flow. [NATCON code]
A means of determining the thermal responses of the core and the components of a high-temperature gas-cooled reactor after loss of forced coolant flow is discussed. A computer program, using a finite-difference technique, is presented together with a solution of the confined natural convection. The results obtained are reasonable and demonstrate that the computer program adequately represents the confined natural convection.
Date:
September 1, 1976
Creator:
Whaley, R. L. & Sanders, J. P.
Object Type:
Report
System:
The UNT Digital Library
Experiment data report for semiscale Mod-1 test S-06-6 (LOFT counterpart test). [PWR]
Recorded test data are presented for Test S-06-6 of the Semiscale Mod-1 LOFT counterpart test series. These tests are among several Semiscale Mod-1 experiments conducted to investigate the thermal and hydraulic phenomena accompanying a hypothesized loss-of-coolant accident in a pressurized water reactor (PWR) system. Test S-06-6 was conducted from initial conditions of 15 792 kPa and 563 K to investigate the response of the Semiscale Mod-1 system to a depressurization and reflood transient following a simulated double-ended offset shear of the broken loop cold leg piping. During the test, cooling water was injected into the cold leg of the intact loop to simulate emergency core coolant injection in a PWR. The heater rods in the electrically heated core were operated at an axial peak power density which was 75% of the maximum peak power density (52.5 kW/m). Test S-06-6 also evaluated the effect of special hardware assumptions on the core response.
Date:
September 1, 1977
Creator:
Esparza, V. & Sackett, K. E.
Object Type:
Report
System:
The UNT Digital Library
The analog processing system for the Liquid Argon Calorimeter for SLD at SLAC
The analog processing system for the Liquid Argon Calorimeter for the SLD project at SLAC is described. Amplification, storage of the analog information, and multiplexing is realized on specially developed hybrids, which will be mounted directly on the detector. This leads to a substantial reduction of the cable plant. Test results for the amplifier and for the sampling and multiplexing hybrid (CDU hybrid) are presented. The latter hybird contains a custom monolithic device, the Calorimeter Data Unit (CDU).
Date:
September 1, 1986
Creator:
Haller, G. M.; Nelson, D. & Freytag, D. R.
Object Type:
Article
System:
The UNT Digital Library
Photoionization cross sections and radiative recombination rate coefficients for positive ions of carbon and gold
Partial photoionization cross sections based on a nonhydrogenic single-electron model that utilizes Dirac--Slater wave functions and all necessary multipoles have been computed for C III-VI and Au + 8, +16, +24, and +36 for n = 1 - 6 and 10, 0 less than or equal to l < n. By use of detailed balance, radiative recombination rate coefficients are obtained for seven temperatures in the range 10 eV - 3 keV from the photoionization cross sections. The cross sections are compared with those obtained by others using semiclassical (Kramers) and hydrogenic models. In most cases, the recombination rate coefficients (summed over subshells) are larger than those computed using hydrogenic photoionization cross sections, by as much as a factor 30 (Au + 8, n = 5, kT = 43 keV). Analytical fits are given for the rate coefficients summed over l and n. The results are applicable to ionization balance and ion transport calculations for fusion reactors and the solar corona.
Date:
September 1, 1977
Creator:
Barfield, W. D.
Object Type:
Report
System:
The UNT Digital Library