Resource Type

26,926 Matching Results

Results open in a new window/tab.

0-D study of the compression of low temperature spheromaks (open access)

0-D study of the compression of low temperature spheromaks

Compression of low temperature spheromak plasmas has been studied with the aid of a O-D two-fluid computer code. It is found that in a plasma which is radiation dominated, the electron temperature can be increased by up to a factor of seven for a compression of a factor of two, provided the temperature is above some critical value (approx.25eV) and the electron density particle confinement time product n/sub e/tau/sub p/ greater than or equal to 1 x 10/sup 9/s/cm/sup 3/. If the energy balance is dominated by particle confinement losses rather than radiation losses, the effect of compression is to raise the temperature as T/sub e/ approx.C/sup 6/5/, for constant tau/sub p/.
Date: September 1, 1985
Creator: Meyerhofer, D. D.; Hulse, R. A. & Zweibel, E. G.
System: The UNT Digital Library
1-MWE Heat Exchangers for OTEC Final Design Report (open access)

1-MWE Heat Exchangers for OTEC Final Design Report

The design of a 1 MWe OTEC heat exchanger is documented, including the designs of the evaporator and associated systems, condenser, instrumentation, and materials for corrosion/erosion control and fabrication processes. (LEW)
Date: June 19, 1980
Creator: Sprouse, A.M.
System: The UNT Digital Library
1/N (open access)

1/N

There exist families of field theories with symmetry group SO(N) (or SU(N)) that become simpler as N becomes larger. More precisely, the solutions to these theories possess an expansion in powers of 1/N. This expansion is the subject of these lectures. The 1/N expansion can be used to analyze model field theories. The 1/N expansion is developed for phi/sup 4/ theory and applied to two two-dimensional models with similar combinatoric structures, the Gross-Neveu model and the CP/sup N-1/ model. These models display (in the leading 1/N approximation) such interesting phenomena as asymptotic freedom, dynamical symmetry breaking, dimensional transmutation, and non-perturbative confinement. It is possible that the 1/N expansion, with N the number of colors, might fruitfully be applied to quantum chromodynamics. Unfortunately, it is not possible to make a decisive test of the approximation, because no one knows how to compute even the first term in the expansion in closed form. However, it is possible to argue that this first term, whatever its detailed form, has many properties that are also shared by the real world, and which are otherwise underived from field theory. These include the saturation of scattering amplitudes by an infinite number of narrow resonances, the essential …
Date: March 1, 1980
Creator: Coleman, S.
System: The UNT Digital Library
1 to 2 GeV/c beam line for hypernuclear and kaon research (open access)

1 to 2 GeV/c beam line for hypernuclear and kaon research

A kaon beam line operating in the range from 1.0 to 2.0 GeV/c is proposed. The line is meant for kaon and pion research in a region hitherto inaccessible to experimenters. Topics in hypernuclear and kaon physics of high current interest include the investigation of doubly strange nuclear systems with the K/sup -/,K/sup +/ reaction, searching for dibaryon resonances, hyperon-nucleon interactions, hypernuclear ..gamma.. rays, and associated production of excited hypernuclei. The beam line would provide separated beams of momentum analyzed kaons at intensities greater than 10/sup 6/ particles per spill with a momentum determined to one part in a thousand. This intensity is an order of magnitude greater than that currently available. 63 references.
Date: February 15, 1985
Creator: Chrien, R. E.
System: The UNT Digital Library
2-D ACAR measurements of Ni/sub 3/A1 (open access)

2-D ACAR measurements of Ni/sub 3/A1

In connection with a detailed study of the electronic structure and stability of the aluminides (Ni,Fe)/sub 3/Al, 2-D ACAR positron annihilation measurements were made on a Ni/sub 3/Al single crystal to study the Fermi surface. The results for Ni/sub 3/Al have been compared with results for pure Ni. Strong similarities were found for the electronic structures of these materials. Theoretical calculations of the Fermi surface for Ni/sub 3/Al are in good agreement with the experimental results. The GAMMA/sub 16/ sheet, not previously observed in any experiment, has now been observed for the first time in Ni/sub 3/Al. 14 refs., 10 figs.
Date: July 1987
Creator: Smedskjaer, L. C.; DasGupta, A.; Legnini, D. G. & Stahulak, M. D.
System: The UNT Digital Library
2-D emittance equation with acceleration and compression (open access)

2-D emittance equation with acceleration and compression

Since both acceleration and compression are required for an Inertial Fusion Driver, the understanding of their effect on the beam quality, emittance, is important. This report attempts to generalize the usual emittance formula for the drifting beam to include these effects. The derivation of the 2-D emittance equation is carried out and a comparison with the particle code results is given. The 2-D emittance at a given axial location is reasonable to consider for a long beam, particularly with velocity tilt; transverse emittance averaged over the entire bunch is not a useful quantity. 6 refs., 2 figs., 1 tab.
Date: October 1, 1988
Creator: Hahn, K. D. & Smith, L.
System: The UNT Digital Library
2-D skin-current toroidal-MHD-equilibrium code (open access)

2-D skin-current toroidal-MHD-equilibrium code

A two-dimensional, toroidal, ideal MHD skin-current equilibrium computer code is described. The code is suitable for interactive implementation on a minicomptuer. Some examples of the use of the code for design and interpretation of toroidal cusp experiments are presented.
Date: September 1, 1982
Creator: Feinberg, B.; Niland, R. A.; Coonrod, J. & Levine, M. A.
System: The UNT Digital Library
2-D time evolution of T/sub e/ during sawtooth crash based on fast ECE (electron cyclotron emission) measurements on TFTR (open access)

2-D time evolution of T/sub e/ during sawtooth crash based on fast ECE (electron cyclotron emission) measurements on TFTR

Electron cyclotron emission measurements taken at 20 locations in the horizontal midplane during a sawtooth crash have been analysed based on the assumption of fast rigid rotation of the plasma. Due to this fast rotation (approx.100..mu..sec), which remains fairly constant throughout the sawtooth crash, we have been able to make time-to-space reconstructions of half the poloidal plane using points which are separated in time by not more than 40..mu..sec. The existence of a temperature flattening in the precursor phase, which we interpret as an m = 1 temperature island, is clearly demonstrated, and its location and width agree well with local emissivity measurements from soft x-ray tomography viewing the same poloidal plane. The rotating temperature island in the precursor phase, the outward movement of the region of high T/sub c/ during the crash phase, and the shape of T/sub e/ during the crash phase, and the shape of T/sub e/ distribution after the crash during the successor phase have all been documented in a time sequence of color contours. 4 refs., 10 figs.
Date: December 1, 1988
Creator: Kuo-Petravic, G.
System: The UNT Digital Library
2-Dimensional studies of the disk-and-washer and side-coupled resonant cavity structures (open access)

2-Dimensional studies of the disk-and-washer and side-coupled resonant cavity structures

The work done consists of three parts: optimizing the disk-and-washer (DAW) structure at ..beta.. = 0.5662 corresponding to E = 200 MeV; comparing the DAW structure with the side-coupled (SCS) structure at various values of beta, ranging from ..beta.. = 0.4569 and E = 116 MeV to ..beta.. = 0.7131 and E = 400 MeV; and re-optimizing the DAW structure at ..beta.. = 0.7131. 4 refs., 51 figs., 41 tabs.
Date: December 1, 1987
Creator: Larry, L.D. Jr.
System: The UNT Digital Library
2, Pulse-mode expansions and refractive indices in plane-wave propagation (open access)

2, Pulse-mode expansions and refractive indices in plane-wave propagation

This memo presents basic background theory for treating simultaneous propagation of electromagnetic pulses of various colors, directed along a common ray, through a molecular vapor. The memo discusses some techniques for expanding the positive frequency part of the transverse electric field into pulse modes, characterized by carrier frequencies within a modulated envelope. We discuss, in the approximation of plane waves with slowly varying envelopes, a set of uncoupled envelope equations in which a polarization mode-envelope acts as a source for an electric-field envelope. These equations, when taken with a prescription for the polarization field, are the basic equations of plane-wave pulse propagation through a molecular medium. We discuss two ways of treating dispersive media, one based upon expansions in the frequency domain and the other based in the time domain. In both cases we find envelope equations that involve group velocities. This memo represents a portion of a more extensive treatment of propagation to be presented separately. Many of the equations presented here have been described in various books and articles. They are collected and described here as a summary and review of contemporary theory.
Date: June 20, 1987
Creator: Shore, B. W.; Sacks, R.; Karr, T.; Morris, J. & Paisner, J. A.
System: The UNT Digital Library
3-D computer simulations of EM field sin the APS vacuum chamber. Part 2: Time-domain analysis (open access)

3-D computer simulations of EM field sin the APS vacuum chamber. Part 2: Time-domain analysis

Our simulations suggest that the strong peak around 4 GHz in the narrow gap observed in the measurements is generated by TE modes. Therefore, one should not worry about this peak insofar as the coupling impedance is concerned. On the other hand, some discrepancies between our simulations and the measurements are noticed and remain to be resolved.
Date: January 20, 1989
Creator: Chou, W.
System: The UNT Digital Library
3-D Nonlinear Calculations of Resistive Tearing Modes (open access)

3-D Nonlinear Calculations of Resistive Tearing Modes

Recent numerical calculations of the evolution of resistive tearing modes have been central to the understanding of magnetohydrodynamic activity and disruptions in tokamaks. The nonlinear, 3-D, initial-value computer code RSF has provided many of these results. This code assumes cylindrical geometry with a Fourier series representation in the two periodic coordinates and a finite-difference representation in the radial direction. This choice makes RSF considerably more accurate and efficient than previous codes.
Date: March 1, 1981
Creator: Hicks, H. R.; Holmes, J. A.; Lee, D. K.; Carreras, B. & Waddell, B. V.
System: The UNT Digital Library
3-D numerical analysis of a high-gain free-electron laser (open access)

3-D numerical analysis of a high-gain free-electron laser

We present a novel approach to the 3-dimensional high-gain free- electron laser amplifier problem. The method allows us to write the laser field as an integral equation which can be efficiently and accurately evaluated on a small computer. The model is general enough to allow the inclusion of various initial electron beam distributions to study the gain reduction mechanism and its dependence on the physical parameters. 16 refs., 8 figs., 1 tab.
Date: October 19, 1988
Creator: Gallardo, J.C.
System: The UNT Digital Library
3-D transient eddy current calculations for the FELIX cylinder experiments (open access)

3-D transient eddy current calculations for the FELIX cylinder experiments

The three-dimensional eddy current transient field problem is formulated first using the U-V method. This method breaks the vector Helmholtz equation into two scalar Helmholtz equations. Null field integral equations and the appropriate boundary conditions are used to set up an identification matrix which is independent of null field point locations. Embedded in the identification matrix are the unknown eigenvalues of the problem representing its impulse response in time. These eigenvalues are found by equating the determinant of the identification matrix to zero. When this initial forcing function is Fourier decomposed into its spatial harmonics, each Fourier component can be associated with a unique eigenvalue by this technique. The true transient solution comes through a convolution of the impulse response so obtained with the particular external field decay governing the problem at hand. The technique is applied to the FELIX cylinder experiments; computed results are compared to data. A pseudoanalytic confirmation of the eigenvalues so obtained is formulated to validate the procedure.
Date: December 1, 1986
Creator: Davey, K. R. & Turner, L. R.
System: The UNT Digital Library
T-3 electron-beam-excited laser system (open access)

T-3 electron-beam-excited laser system

A laser system specifically designed to study the kinetics of electron-beam driven systems is described. Details of the system are given along with measurements of the electron-beam uniformity and deposition in the laser medium. Some HF laser results obtained with this system are also given.
Date: February 1, 1981
Creator: Klein, R. A.
System: The UNT Digital Library
A 3 TeV on 3 TeV proton-proton dedicated collider for Fermilab (open access)

A 3 TeV on 3 TeV proton-proton dedicated collider for Fermilab

The Fermilab Dedicated Collider proposed in May 1983 is a 2 TeV on 2 TeV p)bar p) collider. The expected luminosity is )approximately) 10/sup 31/ cm/sup (minus/2)sec/sup )minus/1) and the estimated cost is )approximately) $362M (FY-83 dollars). Since 1983 both the superconducting magnet and the particle detector technologies have advanced and the countenance of physics, hence the desired characteristics of new facilities have also altered somewhat. We want to show here that with the new magnet technology used for the SSC one can construct a 3 TeV on 3 TeV pp collider on the Fermilab site. This pp Dedicated Collider )PPDC) will have a luminosity of about 10/sub 33/cm/sup )minus/2)sec)sup)minus)1) and a cost only )approximately) 50)percent) more than that of the p)bar p) Dedicated Collider. 3 figs
Date: March 30, 1988
Creator: Teng, L.C.
System: The UNT Digital Library
4 K to 20 K Rotational-Cooling Magnetic Refrigerator Capable of 1-Mw to >1-W Operation (open access)

4 K to 20 K Rotational-Cooling Magnetic Refrigerator Capable of 1-Mw to >1-W Operation

The low-temperature, magnetic entropy of certain single-crystal paramagnetic materials, such as DyPO/sub 4/, changes dramatically as the crystal rotates in a magnetic field. A new magnetic refrigerator design based on the anisotropic nature of such materials is presented. The key advantages of the rotational-cooling concept are (1) a single, rotary motion is required, (2) magnetic field shaping is not a problem because the entire working material is in a constant field, and (3) the refrigerator can be smaller than comparable magnetic refrigerators because the working material is entirely inside the magnet at all times. The main disadvantage of the rotational-cooling concept is that small-dimension single crystals are required.
Date: February 1, 1980
Creator: Barclay, J. A.
System: The UNT Digital Library
6 GeV light source project cost estimating procedure (open access)

6 GeV light source project cost estimating procedure

To maintain uniformity in estimating the cost requirements of the various components of the 6 GeV Light Source, the following procedure will be used by all the task groups. The procedure uses a Work Breakdown Structure (VBS) to break down the project into manageable, easy to estimate, components. The project is first broken down into major tasks or categories. Then each major division is continuously subdivided until the desired level of detail is achieved. This can be shown best by using the example of the WBS of the Aladdin Upgrade Project, excerpts of which are included in Appendix A.
Date: October 23, 1985
Creator: unknown
System: The UNT Digital Library
6 GeV synchrotron x-ray source: Conceptual design report. Supplement A - characteristics of the insertion devices for the 6 GeV synchrotron source (open access)

6 GeV synchrotron x-ray source: Conceptual design report. Supplement A - characteristics of the insertion devices for the 6 GeV synchrotron source

Historically, synchrotron radiation (SR) has been obtained primarily from bending-magnet (BM) sources. These continuous sources of electromagnetic radiation have contributed in a major way to our understanding of the structure and dynamics of biological, chemical and material systems. During the past few years, newer sources of SR based on sophisticated periodic magnetic structures, called insertion devices (IDs), have been developed. The electromagnetic radiation from these IDs can be used as a very versatile probe in scientific and technological research which is far superior to that based on a BM source.
Date: March 1, 1986
Creator: unknown
System: The UNT Digital Library
7-GeV Advanced Photon Source : Conceptual Design Report (open access)

7-GeV Advanced Photon Source : Conceptual Design Report

During the past decade, synchrotron radiation emitted by circulating electron beams has come into wide use as a powerful, versatile source of x-rays for probing the structure of matter and for studying various physical processes. Several synchrotron radiation facilities with different designs and characteristics are now in regular operation throughout the world, with recent additions in this country being the 0.8-GeV and 2.5-GeV rings of NSLS at Brookhaven National Laboratory. However, none of the operating facilities has been designed to use a low-emittance, high-energy stored beam, together with modern undulator devices, to produce a large number of hard x-ray beams of extremely high brilliance. This document is a proposal to the Department of Energy to construct and operate high-energy synchrotron radiation facility at Argonne National Laboratory. We have now chosen to set the design energy of this facility at 7.0 GeV, with the capability to operate at up to 7.5 GeV.
Date: April 1987
Creator: Argonne National Laboratory
System: The UNT Digital Library
7-GeV Advanced Photon Source Conceptual Design Report (open access)

7-GeV Advanced Photon Source Conceptual Design Report

During the past decade, synchrotron radiation emitted by circulating electron beams has come into wide use as a powerful, versatile source of x-rays for probing the structure of matter and for studying various physical processes. Several synchrotron radiation facilities with different designs and characteristics are now in regular operation throughout the world, with recent additions in this country being the 0.8-GeV and 2.5-GeV rings of NSLS at Brookhaven National Laboratory. However, none of the operating facilities has been designed to use a low-emittance, high-energy stored beam, together with modern undulator devices, to produce a large number of hard x-ray beams of extremely high brilliance. This document is a proposal to the Department of Energy to construct and operate high-energy synchrotron radiation facility at Argonne National Laboratory. We have now chosen to set the design energy of this facility at 7.0 GeV, with the capability to operate at up to 7.5 GeV.
Date: April 1, 1987
Creator: unknown
System: The UNT Digital Library
10-MWe solar-thermal central-receiver pilot plant, solar facilities design integration: collector-field optimization report (RADL item 2-25) (open access)

10-MWe solar-thermal central-receiver pilot plant, solar facilities design integration: collector-field optimization report (RADL item 2-25)

Appropriate cost and performance models and computer codes have been developed to carry out the collector field optimization, as well as additional computer codes to define the actual heliostat locations in the optimized field and to compute in detail the performance to be expected of the defined field. The range of capabilities of the available optimization and performance codes is described. The role of the optimization code in the definition of the pilot plant is specified, and a complete description of the optimization process itself is given. The detailed cost model used by the optimizer for the commercial system optimization is presented in the form of equations relating the cost element to each of the factors that determine it. The design basis for the commercial system is presented together with the rationale for its selection. The development of the individual heliostat performance code is presented. Use of the individual heliostat code in a completed study of receiver panel power under sunrise startup conditions is described. The procedure whereby performance and heliostat spacing data from the representative commercial-scale system are converted into coefficients of use in the layout processor is described, and the actual procedure used in the layout processor is …
Date: January 1, 1981
Creator: unknown
System: The UNT Digital Library
10-MWe solar-thermal central-receiver pilot plant, solar-facilities design integration: plant-support subsystem procurement documentation (RADL Item 7-44D) (open access)

10-MWe solar-thermal central-receiver pilot plant, solar-facilities design integration: plant-support subsystem procurement documentation (RADL Item 7-44D)

Purchase specifications are given for the specific long lead items to be procured for the 10 MWe Solar Pilot Plant. The hardware is grouped into two categories: 480 Volt Load Center and 480 Volt Motor Control Centers; and Power, Control and Instrumentation Cable. The purchase orders for each procurement are included. Need dates for each item are identified. (LEW)
Date: September 1, 1980
Creator: unknown
System: The UNT Digital Library
10-MWe solar-thermal central-receiver pilot plant, solar-facilities design integration: system integration laboratory test plan (RADL item 6-4) (open access)

10-MWe solar-thermal central-receiver pilot plant, solar-facilities design integration: system integration laboratory test plan (RADL item 6-4)

A general demonstration test plan is provided for the activities to be accomplished at the Systems Integration Laboratory. The Master Control System, Subsystem Distributed Process Control, Representative Signal Conditioning Units, and Redline Units from the Receiver Subsystem and the Thermal Storage Subsystem and other external interface operational functions will be integrated and functionally demonstrated. The Beckman Multivariable Control Unit will be tested for frequency response, static checks, configuration changes, switching transients, and input-output interfaces. Maximum System Integration Laboratory testing will demonstrate the operational readiness of Pilot Plant controls and external interfaces that are available. Minimum System Integration Laboratory testing will be accomplished with reduced set of hardware, which will provide capability for continued development and demonstration of Operational Control System plant control application software. Beam Control System Integration Laboratory testing will demonstrate the operational readiness of the Beam Control System equipment and software. (LEW)
Date: October 1, 1980
Creator: unknown
System: The UNT Digital Library