Some frontiers of accelerator physics (open access)

Some frontiers of accelerator physics

This paper discusses some concepts of future accelerators such as free electron lasers, two beam accelerator; and plasma-based adiabatic compressor. 12 refs., 10 figs., 5 tabs. (LSP)
Date: October 13, 1989
Creator: Sessler, A. M.
Object Type: Article
System: The UNT Digital Library
Geothermal Injection Monitoring Project. Phase I status report, April 1981-April 1982 (open access)

Geothermal Injection Monitoring Project. Phase I status report, April 1981-April 1982

The feasibility of using remote geophysical techniques to monitor the movement of injected brine has been evaluated. It was established that no single approach is likely to be identified that can be used to accurately monitor the precise location of the injected fluid. Several approaches have been considered in parallel because they add new dimensions to the existing monitoring capabilities, and are likely to cover a range of applications at a variety of geothermal sites. These include: microseismicity - a seismic net is used to record small magnitude events associated with injection; streaming potential - self potential anomalies produced by a moving fluid identify fluid flow direction; cross borehole geotomography - two-dimensional image of flow pathways is constructed using electromagnetic waves; and well pressure response to solid earth tide - changes in pore pressures are used to discriminate fracture/pore porosity and estimate fracture orientations.
Date: August 13, 1982
Creator: Younker, L.; Hanson, J.; Didwall, E.; Kasameyer, P.; Smith, A.; Hearst, J. et al.
Object Type: Report
System: The UNT Digital Library
MPS II drift-chamber system (open access)

MPS II drift-chamber system

A new system of detectors (MPS II) which has been installed and operated in the Brookhaven National Laboratory Multiparticle Spectrometer (MPS), consisting of short drift distance drift chambers is briefly described. (WHK)
Date: May 13, 1982
Creator: Etkin, A.; Eiseman, S. & Foley, K.J.
Object Type: Article
System: The UNT Digital Library
Plasma Separation Process: Betacell (BCELL) code: User's manual. [Bipolar barrier junction] (open access)

Plasma Separation Process: Betacell (BCELL) code: User's manual. [Bipolar barrier junction]

The emergence of clearly defined applications for (small or large) amounts of long-life and reliable power sources has given the design and production of betavoltaic systems a new life. Moreover, because of the availability of the plasma separation program, (PSP) at TRW, it is now possible to separate the most desirable radioisotopes for betacell power generating devices. A computer code, named BCELL, has been developed to model the betavoltaic concept by utilizing the available up-to-date source/cell parameters. In this program, attempts have been made to determine the betacell energy device maximum efficiency, degradation due to the emitting source radiation and source/cell lifetime power reduction processes. Additionally, comparison is made between the Schottky and PN junction devices for betacell battery design purposes. Certain computer code runs have been made to determine the JV distribution function and the upper limit of the betacell generated power for specified energy sources. A Ni beta emitting radioisotope was used for the energy source and certain semiconductors were used for the converter subsystem of the betacell system. Some results for a Promethium source are also given here for comparison. 16 refs.
Date: November 13, 1987
Creator: Taherzadeh, M.
Object Type: Report
System: The UNT Digital Library
Capital requirements for the transportation of energy materials: 1979 ARC estimates. Draft final report (open access)

Capital requirements for the transportation of energy materials: 1979 ARC estimates. Draft final report

This report contains TERA's estimates of capital requirements to transport natural gas, crude oil, petroleum products, and coal in the United States by 1990. The low, medium, and high world-oil-price scenarios from the EIA's Mid-range Energy Forecasting System (MEFS), as used in the 1979 Annual Report to Congress (ARC), were provided as a basis for the analysis and represent three alternative futures. TERA's approach varies by energy commodity to make best use of the information and analytical tools available. Summaries of transportation investment requirements through 1990 are given. Total investment requirements for three modes (pipelines, rails, waterways and the three energy commodities can accumulate to a $49.9 to $50.9 billion range depending on the scenario. The scenarios are distinguished primarily by the world price of oil which, given deregulation of domestic oil prices, affects US oil prices even more profoundly than in the past. The high price of oil, following the evidence of the last year, is projected to hold demand for oil below the recent past.
Date: August 13, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Urban Options Solar Greenhouse Project. Semi-annual technical progress report (open access)

Urban Options Solar Greenhouse Project. Semi-annual technical progress report

The design changes and construction of the Urban Options Solar Greenhouse are described. The greenhouse performance and horticultural and educational activities are discussed. (MHR)
Date: March 13, 1980
Creator: Cipparone, L.
Object Type: Report
System: The UNT Digital Library
Annular air space effects on nuclear waste canister temperatures in a deep geologic waste repository (open access)

Annular air space effects on nuclear waste canister temperatures in a deep geologic waste repository

Air spaces in a deep geologic repository for nuclear high level waste will have an important effect on the long-term performance of the waste package. The important temperature effects of an annular air gap surrounding a high level waste canister are determined through 3-D numerical modeling. Air gap properties and parameters specifically analyzed and presented are the air gap size, surfaces emissivity, presence of a sleeve, and initial thermal power generation rate; particular emphasis was placed on determining the effect of these variables have on the canister surface temperature. Finally a discussion based on modeling results is presented which specifically relates the results to NRC regulatory considerations.
Date: May 13, 1980
Creator: Lowry, W.E.; Cheung, H. & Davis, B.W.
Object Type: Report
System: The UNT Digital Library
Neutral beam injector for 475 keV MARS sloshing ions (open access)

Neutral beam injector for 475 keV MARS sloshing ions

A neutral beam injector system which produces 5 MW of 475 keV D/sup 0/ neutrals continuously on target has been designed. The beamline is intended to produce the sloshing ion distribution required in the end plug region of the conceptual MARS tandem mirror commercial reactor. The injector design utilizes the LBL self-extraction negative ion source and Transverse Field Focusing (TFF) accelerator to generate a long, ribbon ion beam. A laser photodetachment neutralizer strips over 90% of the negative ions. Magnetic and neutron shield designs are included to exclude the fringe fields of the end plug and provide low activation by the neutron flux from the target plasma. The use of a TFF accelerator and photodetachment neutralizer produces a total system electrical efficiency of about 63% for this design.
Date: December 13, 1983
Creator: Goebel, D.M. & Hamilton, G.W.
Object Type: Report
System: The UNT Digital Library
A fast large-area position-sensitive time-of-flight neutron detection system (open access)

A fast large-area position-sensitive time-of-flight neutron detection system

A new position-sensitive time-of-flight neutron detection and histograming system has been developed for use at the Intense Pulsed Neutron Source. Spatial resolution of roughly 1 cm {times} 1 cm and time-of-flight resolution of {approximately}1 {mu}sec are combined in a detection system which can ultimately be expanded to cover several square meters of active detector area. This system is based on the use of arrays of cylindrical one-dimensional position-sensitive proportional counters, and is capable of collecting the x-y-t data and sorting them into histograms at time-averaged data rates up to {approximately}300,000 events/sec over the full detector area and with instantaneous data rates up to more than fifty times that. Numerous hardware features have been incorporated to facilitate initial tuning of the position encoding, absolute calibration of the encoded positions, and automatic testing for drifts. 7 refs., 11 figs., 1 tabs.
Date: October 13, 1989
Creator: Crawford, R.K. & Haumann, J.R.
Object Type: Article
System: The UNT Digital Library
Steering system for a train of rail-less vehicles (open access)

Steering system for a train of rail-less vehicles

A steering system for use with a multiple vehicle train is disclosed which permits tracking without rails of one vehicle after another. This system is particularly useful for moving conveyor systems into and out of curved paths of room and pillar underground mine installations. The steering system features an elongated steering bar pivotally connected to each of adjacent vehicles at end portions of the bar permitting angular orientation of each vehicle in respect to the steering bar and other vehicles. Each end portion of the steering bar is linked to the near pair of vehicle wheels through wheel yoke pivot arms about king pin type pivots. Movement of the steering bar about its pivotal connection provides proportional turning of the wheels to effect steering and tracking of one vehicle following another in both forward and reverse directions.
Date: March 13, 1981
Creator: Voight, Edward Theodore
Object Type: Patent
System: The UNT Digital Library
Review of free electron laser theory and experiments (open access)

Review of free electron laser theory and experiments

A review of the major Free Electron Laser (FEL) experiments will be presented. These experiments are designed to produce radiation at wavelengths from the far infrared to the ultraviolet. Different categories of FELs (Compton, Raman, optical klystron, two stage, etc.), as well as the suitability of various types of electron accelerators to power FELs, will also be discussed. Potential applications of the FEL will be summarized.
Date: January 13, 1984
Creator: Prosnitz, D.
Object Type: Article
System: The UNT Digital Library
Electromagnetic Effects in Relativistic Electron Beam Plasma Interactions (open access)

Electromagnetic Effects in Relativistic Electron Beam Plasma Interactions

Electromagnetic effects excited by intense relativistic electron beams in plasmas are investigated using a two-dimensional particle code. The simulations with dense beams show large magnetic fields excited by the Weibel instability as well as sizeable electromagnetic radiation over a significant range of frequencies. The possible relevance of beam plasma instabilities to the laser acceleration of particles is briefly discussed. 6 refs., 4 figs.
Date: February 13, 1985
Creator: Kruer, W. L. & Langdon, A. B.
Object Type: Article
System: The UNT Digital Library
Thermal properties measurements on rocksalt samples from the site of the proposed Waste Isolation Pilot Plant (open access)

Thermal properties measurements on rocksalt samples from the site of the proposed Waste Isolation Pilot Plant

Thermal conductivity, thermal expansion, and specific heat measurements have been made on a number of specimens. The specific heat measurements were made by differential scanning calorimetry and the results showed that the specific heats of both clean rocksalt samples and of dirty samples with less than or equal to 7% insoluble impurities were essentially identical to the published specific heat for pure NaCl. In the thermal expansion measurements, two distinct groups of samples were identified. The first group had average expansion coefficients in the temperature range 300 to 700/sup 0/K close to that reported for pure NaCl. All the samples in this group were composed predominantly of halite, with only small amounts of other minerals or materials present. A second group of samples had expansion coefficients only approx. 0.3 to 0.5 that of NaCl. The samples in this group were composed largely of polyhalite, anhydrite, or siltstone. The measurements first reported by Acton on the thermal conductivity of samples taken from a borehole at the site of the proposed nuclear waste isolation pilot plant (WIPP) near Carlsbad, NM, have been extended to include additional samples and higher temperature measurements. This is not believed to be the result of the onset …
Date: May 13, 1980
Creator: Sweet, J. N. & McCreight, J. E.
Object Type: Report
System: The UNT Digital Library
ITER disruption modeling using TSC (Tokamak Simulation Code) (open access)

ITER disruption modeling using TSC (Tokamak Simulation Code)

Design of the ITER vacuum vessel (VV) is driven strongly by disruption-induced forces. We use the Tokamak Simulation Code (TSC) to model disruptions for the ITER physics phase (I{sub p} = 22 MA) and predict the time evolution of currents and forces on the VV. For a plasma vertically displaced to Z{sub axis} = {minus}1.0m before disruption and decaying at a rate of < dI{sub p}/dt > {approx equal} {minus}1.0MA/ms, the induced VV current peaks at 18 MA. The maximum radial VV force F{sub R} is 56 MN/rad; the maximum vertical force F{sub Z} is 5.4 MN/rad; and the maximum VV disruption pressure is 1.0 MPa. Variations in VV resistance (20 - 160 {mu}{Omega}) and < dI{sub p}/dt > (1 - 2.5 MA/ms) do not change F{sub R} significantly. The dependence of the forces on the initial plasma displacement and < dI{sub p}/dt > behavior, and the responses of other conducting structures are discussed. 2 refs., 6 figs.
Date: November 13, 1989
Creator: Sayer, R. O.; Peng, Y. K. M.; Wesley, J. C.; Jardin, S. C. (Oak Ridge National Lab., TN (USA); General Atomics, San Diego, CA (USA) & Princeton Univ., NJ (USA). Plasma Physics Lab.)
Object Type: Article
System: The UNT Digital Library
Modeling beam-front dynamics at low gas pressures (open access)

Modeling beam-front dynamics at low gas pressures

The dynamics of space charge neutralization at the front of an intense self-focused electron beam pulse exhibits important differences in different gas pressure regimes. At very low pressures, the beam front is in the so-called ion-focused regime (IFR) where all secondary electrons are expelled from the beam region by the radial electric field without causing significant additional ionization. We estimate the upper pressure boundary of this regime by considering the distance scale length for cascade (avalanche) ionization. Data from the FX-25 diode experiments indicate a critical transition pressure (P/sub c/) that agrees with this estimate and with its scaling among various gas types. Normal mobility-limited treatments (local conductivity models) of the secondary electrons at the beam front are not justified until the gas pressure is 10 to 50 times higher than P/sub c/, due to runaway of these secondary electrons in the strong space-charge electric field at the lower pressures. The main conclusion of this study is that a non-local phase space (Boltzmann) treatment of the secondary electrons is required to accurately describe these different beam front regimes and the transitions between them; such a code model is currently under development.
Date: May 13, 1982
Creator: Briggs, R. J. & Yu, S.
Object Type: Report
System: The UNT Digital Library
L-shell photoabsorption spectroscopy for solid metals: Ti, V, Cr, Fe, Ni, Cu (open access)

L-shell photoabsorption spectroscopy for solid metals: Ti, V, Cr, Fe, Ni, Cu

Synchrotron radiation measurements of near-threshold and broad-range (400--1500 eV) absolute photoabsorption cross sections were made for five transition metals with {plus minus}10% overall uncertainties. Fine structure details of 2p-3d autoionizing resonances are shown with better than 1.0 eV resolution for solid metals: Ti, V, Cr, Fe, Ni, and Cu. Fine structure similar to what we measured can be produced using a multi-configuration Dirac Fock (MCDF) model if a statistical distribution is assumed for the initial atomic states. Calculations were performed in intermediate coupling with configuration interactions by Mau H. Chen. The results are compared with other experimental work and theoretical methodologies. 18 refs., 7 figs.
Date: September 13, 1989
Creator: Del Grande, N.K. (Lawrence Livermore National Lab., CA (USA))
Object Type: Article
System: The UNT Digital Library
Technical evaluation report on the proposed design modifications and technical specification changes on grid voltage degradation for the Millstone Nuclear Power Station, Unit 1 (open access)

Technical evaluation report on the proposed design modifications and technical specification changes on grid voltage degradation for the Millstone Nuclear Power Station, Unit 1

This report documents the technical evaluation of the proposed design modifications and Technical Specification change for protection of Class 1E equipment from grid voltage degradation for the Millstone Nuclear Power Station, Unit 1. The review criteria are based on several IEEE standards and the Code of Federal Regulations. The evaluation finds that the licensee has not provided sufficient information on the undervoltage protection system to allow a complete evaluation into the adequacy of protecting the Class 1E equipment from sustained voltage degradation.
Date: May 13, 1982
Creator: Selan, J.C.
Object Type: Report
System: The UNT Digital Library
Neutral beamline with improved ion-energy recovery (open access)

Neutral beamline with improved ion-energy recovery

A neutral beamline employing direct energy recovery of unneutralized residual ions is provided which enhances the energy recovery of the full energy ion component of the beam exiting the neutralizer cell, and thus improves the overall neutral beamline efficiency. The unneutralized full energy ions exiting the neutralizer are deflected from the beam path and the electrons in the cell are blocked by a magnetic field applied transverse to the beam direction in the neutralizer exit region. The ions which are generated at essentially ground potential and accelerated through the neutralizer cell by a negative acceleration voltage are collected at ground potential. A neutralizer cell exit end region is provided which allows the magnetic and electric fields acting on the exiting ions to be loosely coupled.
Date: April 13, 1981
Creator: Kim, J.
Object Type: Patent
System: The UNT Digital Library
Mathematical modeling and economic analysis of membrane separation of hydrogen from gasifier synthesis gas (open access)

Mathematical modeling and economic analysis of membrane separation of hydrogen from gasifier synthesis gas

Investigators are studying hydrogen purification by membrane technology as a means to make the coal-to-hydrogen route economically attractive. To allow prediction of membrane performance and to facilitate comparisons between membrane and other technologies (cryogenic distillation, pressure swing adsorption), they developed a mathematical model to describe the permeation process inside a membrane module. The results of this model were compared with available experimental data (separation of CO{sub 2}/O{sub 2}/N{sub 2} mixtures). The model was first used to calculate the gas permeabilities from one set of mixed-gas experiments; the resulting permeabilities were then used to predict the results of the other mixed-gas experiments. The agreement between these predictions and the experimental data was good. However, model predictions using gas permeabilities obtained in pure gas experiments did not agree with the mixed gas experimental data. This disagreement is believed to be due to plasticization of the membrane by contact with CO{sub 2}. These results indicate that data obtained from experiments with mixed-gas feeds are necessary to adequately predict membrane performance when CO{sub 2} is present. The performance of different system configurations, including one and two stages of membrane modules, was examined. The different configurations examined were single module (SM), single module with recycle …
Date: October 13, 1988
Creator: Roberts, D.L. & Gottschlich, D.E.
Object Type: Report
System: The UNT Digital Library
Clinch River breeder reactor sodium fire protection system design and development (open access)

Clinch River breeder reactor sodium fire protection system design and development

To assure the protection of the public and plant equipment, improbable accidents were hypothesized to form the basis for the design of safety systems. One such accident is the postulated failure of the Intermediate Heat Transfer System (IHTS) piping within the Steam Generator Building (SGB), resulting in a large-scale sodium fire. This paper discusses the design and development of plant features to reduce the consequences of the accident to acceptable levels. Additional design solutions were made to mitigate the sodium spray contribution to the accident scenario. Sodium spill tests demonstrated that large sodium leaks can be safely controlled in a sodium-cooled nuclear power plant.
Date: April 13, 1984
Creator: Foster, K.W.; Boasso, C.J. & Kaushal, N.N.
Object Type: Article
System: The UNT Digital Library
Initial measurements of beam breakup instability in the advanced test accelerator (open access)

Initial measurements of beam breakup instability in the advanced test accelerator

This paper reports the measurements of beam breakup (BBU) instability performed on the Advanced Test Accelerator (ATA) up to the end of February, 1984. The main objective was to produce a high current usable electron beam at the ATA output. A well-known instability is BBU which arises from the accelerator cavity modes interacting with the electron beam. The dominant mode is TM/sub 130/ at a frequency of approximately 785 MHz. It couples most strongly to the beam motion and has been observed to grow in the Experimental Test Accelerator (ETA) which has only eight accelerator cavities. ATA has one hundred and seventy cavities and, therefore, the growth of BBU is expected to be more severe. In this paper, BBU measurements are reported for ATA with beam currents of 4 to 7 kA. Analysis showed that the growth of the instability with propagation distance was as expected for the lower currents. However, the high-current data showed an apparent higher growth rate than expected. An explanation for this anomaly is given in terms of a ''corkscrew'' excitation. The injector BBU noise level for a field emission brush cathode was found to be an order of magnitude lower than for a cold plasma …
Date: May 13, 1985
Creator: Chong, Y.P.; Caporaso, G.J. & Struve, K.W.
Object Type: Article
System: The UNT Digital Library
Compressor surge counter (open access)

Compressor surge counter

A surge counter for a rotating compressor is provided which detects surging by monitoring the vibration signal from an accelerometer mounted on the shaft bearing of the compressor. The circuit detects a rapid increase in the amplitude envelope of the vibration signal, e.g., 4 dB or greater in less than one second, which is associated with a surge onset and increments a counter. The circuit is rendered nonresponsive for a period of about 5 seconds following the detection which corresponds to the duration of the surge condition. This prevents multiple registration of counts during the surge period due to rapid swings in vibration amplitude during the period.
Date: April 13, 1981
Creator: Castleberry, K.N.
Object Type: Patent
System: The UNT Digital Library
Receiver for solar-energy collector having improved aperture aspect (open access)

Receiver for solar-energy collector having improved aperture aspect

A secondary concentrator for use in receiver systems for linear focusing primary concentrators is provided with reflector wings at each end. The wings increase the capture of light rays reflected from areas adjacent the rim of a primary concentrator, increasing the apparent aperture size of the receiver as viewed from the rim of the primary concentrator. The length, tilt, and curvature of the wing reflectors can be adjusted to provide a receiver having a desired aperture aspect.
Date: March 13, 1981
Creator: McIntire, W.R.
Object Type: Patent
System: The UNT Digital Library
Two gauge boson physics at future colliders (open access)

Two gauge boson physics at future colliders

Electroweak unification suggests that there should be WW and ZZ physics analogous to {gamma}{gamma} physics. Indeed, WW and ZZ collisions will provide an opportunity to search for the Higgs boson at future high energy colliders. Cross sections in the picobarn range are predicted for Higgs boson production at the proposed 40-TeV SSC. While other states may be produced by WW and ZZ collisions, it is the Higgs boson that looms as the most attractive objective. 31 refs., 5 figs.
Date: May 13, 1988
Creator: Cahn, Robert N.
Object Type: Article
System: The UNT Digital Library