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1.3 GHz superconducting RF cavity program at Fermilab

Description: At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.
Date: March 1, 2011
Creator: Ginsburg, C. M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L. et al.
Partner: UNT Libraries Government Documents Department
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1/N

Description: 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 feature of dual-resonance models. (RWR)
Date: March 1, 1980
Creator: Coleman, S.
Partner: UNT Libraries Government Documents Department
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2-1/2-dimensional numerical solution for the electromagnetic scattering using a hybrid technique

Description: The use of the electromagnetic method for geothermal reservoir exploration and delineation was studied. A number of techniques were developed to provide high quality field data. The remaining problem of interpreting these data in regions of complex geologic structure was overcome by the development of a numerical solution based on the hybrid technique, making use of both the finite element and the integral equation techniques. The major improvement is in the computing speed. (ACR)
Date: March 1, 1983
Creator: Lee, K. H. & Morrison, H. F.
Partner: UNT Libraries Government Documents Department
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2-mm microwave interferometer

Description: A 2-mm microwave interferometer has been developed, and phase shift measurements have been made on the Baseball II experiment. The interferometer system employs a 140-GHz receiver for double down conversion of the plasma signal to a 60-MHz, IF frequency. The 140-GHz references signal is also down-converted and compared with the plasma signal to provide the desired phase change of the signal passing through the plasma. A feedback voltage from a 60-MHz discriminator to a voltage-controlled oscillator in the receiver provides frequency stability of the 60-MHz IF signals.
Date: March 1, 1977
Creator: Futch, A. H. & Mortensen, W. K.
Partner: UNT Libraries Government Documents Department
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3-D Cavern Enlargement Analyses

Description: Three-dimensional finite element analyses simulate the mechanical response of enlarging existing caverns at the Strategic Petroleum Reserve (SPR). The caverns are located in Gulf Coast salt domes and are enlarged by leaching during oil drawdowns as fresh water is injected to displace the crude oil from the caverns. The current criteria adopted by the SPR limits cavern usage to 5 drawdowns (leaches). As a base case, 5 leaches were modeled over a 25 year period to roughly double the volume of a 19 cavern field. Thirteen additional leaches where then simulated until caverns approached coalescence. The cavern field approximated the geometries and geologic properties found at the West Hackberry site. This enabled comparisons are data collected over nearly 20 years to analysis predictions. The analyses closely predicted the measured surface subsidence and cavern closure rates as inferred from historic well head pressures. This provided the necessary assurance that the model displacements, strains, and stresses are accurate. However, the cavern field has not yet experienced the large scale drawdowns being simulated. Should they occur in the future, code predictions should be validated with actual field behavior at that time. The simulations were performed using JAS3D, a three dimensional finite element analysis code for nonlinear quasi-static solids. The results examine the impacts of leaching and cavern workovers, where internal cavern pressures are reduced, on surface subsidence, well integrity, and cavern stability. The results suggest that the current limit of 5 oil drawdowns may be extended with some mitigative action required on the wells and later on to surface structure due to subsidence strains. The predicted stress state in the salt shows damage to start occurring after 15 drawdowns with significant failure occurring at the 16th drawdown, well beyond the current limit of 5 drawdowns.
Date: March 1, 2002
Creator: EHGARTNER, BRIAN L. & SOBOLIK, STEVEN R.
Partner: UNT Libraries Government Documents Department
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3-d finite element model development for biomechanics: a software demonstration

Description: Finite element analysis is becoming an increasingly important part of biomechanics and orthopedic research, as computational resources become more powerful, and data handling algorithms become more sophisticated. Until recently, tools with sufficient power did not exist or were not accessible to adequately model complicated, three-dimensional, nonlinear biomechanical systems. In the past, finite element analyses in biomechanics have often been limited to two-dimensional approaches, linear analyses, or simulations of single tissue types. Today, we have the resources to model fully three-dimensional, nonlinear, multi-tissue, and even multi-joint systems. The authors will present the process of developing these kinds of finite element models, using human hand and knee examples, and will demonstrate their software tools.
Date: March 1, 1997
Creator: Hollerbach, K.; Hollister, A.M. & Ashby, E.
Partner: UNT Libraries Government Documents Department
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3-D Nonlinear Calculations of Resistive Tearing Modes

Description: 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.
Partner: UNT Libraries Government Documents Department
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3-D nonlinear evolution of MHD instabilities

Description: The nonlinear evolution of ideal MHD internal instabilities is investigated in straight cylindrical geometry by means of a 3-D initial-value computer code. These instabilities are characterized by pairs of velocity vortex cells rolling off each other and helically twisted down the plasma column. The cells persist until the poloidal velocity saturates at a few tenths of the Alfven velocity. The nonlinear phase is characterized by convection around these essentially fixed vortex cells. For example, the initially centrally peaked temperature profile is convected out and around to form an annulus of high temperature surrounding a small region of lower temperature. Weak, centrally localized instabilities do not alter the edge of the plasma. Strong, large-scale instabilities, resulting from a stronger longitudinal equilibrium current, drive the plasma against the wall. After three examples of instability are analyzed in detail, the numerical methods and their verification are discussed.
Date: March 1, 1977
Creator: Bateman, G.; Hicks, H. R. & Wooten, J. W.
Partner: UNT Libraries Government Documents Department
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A 3-D SAR approach to IFSAR processing

Description: Interferometric SAR (IFSAR) can be shown to be a special case of 3-D SAR image formation. In fact, traditional IFSAR processing results in the equivalent of merely a super-resolved, under-sampled, 3-D SAR image. However, when approached as a 3-D SAR problem, a number of IFSAR properties and anomalies are easily explained. For example, IFSAR decorrelation with height is merely ordinary migration in 3-D SAR. Consequently, treating IFSAR as a 3-D SAR problem allows insight and development of proper motion compensation techniques and image formation operations to facilitate optimal height estimation. Furthermore, multiple antenna phase centers and baselines are easily incorporated into this formulation, providing essentially a sparse array in the elevation dimension. This paper shows the Polar Format image formation algorithm extended to 3 dimensions, and then proceeds to apply it to the IFSAR collection geometry. This suggests a more optimal reordering of the traditional IFSAR processing steps.
Date: March 1, 2000
Creator: DOERRY,ARMIN W. & BICKEL,DOUGLAS L.
Partner: UNT Libraries Government Documents Department
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4. pi. physics. [/sup 40/Ar + KCl, 0. 4 to 1. 8 GeV/A]

Description: Exclusive ..pi../sup -/ and charged-particle production in collisions of /sup 40/Ar on KCl are studied at incident energies from 0.4 to 1.8 GeV/A. The correlation between the ..pi../sup -/ and the total charged particle multiplicity confines the reaction along a narrow ridge with no exotic islands of pion production. For high multiplicities the system reaches the total disintegration of target and projectile into singly charged fragments and pions. Every 200 MeV/A datum was taken with a central and inelastic trigger. For central collisions the mean ..pi../sup -/ multiplicity increases linearly with the bombarding energy with no marked discontinuities due to the ..delta..(3,3) resonance. At 1.8 GeV/A evidence for nonthermal ..pi../sup -/ production in central collisions is found. The total c.m. energy in ..pi../sup -/ shows linear dependence on the ..pi../sup -/ multiplicity with a slope of epsilon = 300 MeV/..pi../sup -/. Strange particle production in the central collision of 1.8 GeV/A Ar on KCl is seen. 8 figures.
Date: March 1, 1980
Creator: Sandoval, A.
Partner: UNT Libraries Government Documents Department
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6 GeV synchrotron x-ray source: Conceptual design report. Supplement A - characteristics of the insertion devices for the 6 GeV synchrotron source

Description: 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
Partner: UNT Libraries Government Documents Department
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6 GeV synchrotron x-ray source: Conceptual design report. Supplement B - conceptual design of proposed beam lines for the 6 GeV light source

Description: In this document, preliminary conceptual designs are presented for ten sample beamlines for the 6 GeV Light Source. These beamlines will accommodate investigations in solid-state physics, materials science, materials technology, chemical technology, and biological and medical sciences. In future, the designs will be altered to include new developments in x-ray optics and hardware technologies. The research areas addressed by the samples beamlines are as follows: Topography and Radiography/Tomography (section 2); Inelastic Scattering with Ultrahigh Energy Resolution (Section 3); Surface and Bulk Studies Using High Momentum Resolution (Section 4); Inelastic Scattering from Charge and Spin (Section 5); Advanced X-Ray Photoelectron Spectroscopy Studies (Section 6); Small Angle X-Ray Scattering Studies (Section 7); General Purpose Scattering for Materials Studies (Section 8); Multiple-Energy Anomalous-Dispersion Studies of Proteins (Section 9); Protein Crystallography (Section 10); Time- and Space-resolved X-Ray Spectroscopy (Section 11); Medical Diagnostic Facility (Section 12); and Transuranium Research Facility (Section 13). The computer systems to be used on the beamlines are also discussed in Section 14 of this document.
Date: March 1, 1996
Partner: UNT Libraries Government Documents Department
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9. 1-T iron-free Nb-Ti dipole magnet with pancake windings

Description: An eight-pancake Nb-Ti dipole magnet, with bent up ends, called D-108B has been built and tested. This magnet is a Nb-Ti version of a Nb/sub 3/Sn magnet designed to produce a 10-tesla dipole field in a 40 mm diameter aperture. The pancack design is used for the heavy 12,000 ampere Nb/sub 3/Sn cable because of the mechanical difficulty in winding such a heavy cable into the conventional nested cylindrical shell configuration with a 2'' inner winding diameter. The Nb-Ti version operates at 1.8K, in He II, has superconducting cable half as thick as the Nb/sub 3/Sn cable, and operates at half the operating current: 6000 A rather than 12,000 A at 10 tesla. Both magnets are approximately one meter long. D-10B was tested from January 26 to February 2, 1983 and reached short-sample performance in both He I and He II after moderate training. The central field at 4.3K is 7.0 (+- 0.1) tesla, and at 1.8K is 9.1 (+- 0.2) tesla. Ramp rate sensitivity and cyclic heating data were also measured.
Date: March 1, 1983
Creator: Gilbert, W.; Caspi, S.; Hassenzahl, W.; Meuser, R.; Peters, C.; Rechen, J. et al.
Partner: UNT Libraries Government Documents Department
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