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Electron density measurement of an electrostatically-confined, spherically symmetric, helium plasma using a microwave cavity resonance shift technique

Description: Thesis. Microwave resonant cavity frequency shift measurements are made to determine the electron density of an electrostatically confined, spherically symmetric helium plasma. Appropriate electron-density distribution functions are assumed and then used to relate the frequency shift to the central electron density. Results from electron injection, with currents of up to 200 mA, accelerating voltages from 100 to 450 V, and pressures of 5.0, 1.0, and 0.5 mTorr, suggest that a potential well is f… more
Date: August 1, 1973
Creator: Grush, W H
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Enhancing the Performances of ECR Ion Sources

Description: The performances of ECR ion sources can be enhanced in the spatial domain by tailoring the central magnetic field so that it is uniformly distributed over a large plasma volume and is of magnitude so as to be in resonance with single frequency microwave radiation. Analogously, the performances of conventional minimum-B ECR ion sources can be enhanced in the frequency domain by injecting multiple discrete frequency or broadband microwave radiation into their plasma volumes. In this report, examp… more
Date: March 29, 1999
Creator: Alton, G. D. & Liu, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Microwave and accelerator research. Annual report, June 1, 1992

Description: This report describes work carried out on DOE grant number DE-FG02- 92ER40731 during the period June 1, 1992 to the present. The report provides a brief summary of the program objectives, summarizes the main accomplishments and concludes with listings of conference and refereed publications.
Date: June 1, 1993
Creator: Nation, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Nonlinear microwave switching response of BSCCO single crystals

Description: Measurements of the surface impedance in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} single crystal with microwave currents flowing along the {cflx c} axis show clear evidence of a step-like nonlinearity. The surface resistance switches between apparently quantized levels for microwave field strength changes < 1 mG. This nonlinear response can arise from the presence of intrinsic Josephson junctions along the {cflx c} axis of these samples driven by the microwave current.
Date: June 1, 1996
Creator: Jacobs, T.; Sridhar, S.; Willemsen, B. A.; Li, Qiang; Gu, G. D. & Koshizuka, N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Dielectric Properties of Azotobacter vinelandii in a Microwave Field

Description: A resonant frequency cavity was used to determine the dielectric properties of various preparations of Azotobacter vinelandii ATTC 12837. It was found that the bacteria investigated did interact with microwave radiation in the absence of free water. The data presented here indicate that bacteria demonstrate frequency specific dielectric properties. The techniques employed in these experiments may also be used to determine microwave spectra of other species of bacteria in different physiological… more
Date: December 1978
Creator: Hargett, John M.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Signals from Microwave Unstable Beams in the SLC Damping Rings

Description: The longitudinal microwave instability is present in the SLC damping rings during routine operations. Experimental studies of the instability at nominal conditions have been reported previously. To complement those studies and better understand the properties of the instability a series of dedicated experiments were performed under a broad range of operating parameters. These experiments included spectral measurements of BPM signals as well as time domain diagnostics using a custom detecting ci… more
Date: April 5, 1999
Creator: Podobedev, Boris
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Establishing isokinetic flow for a plasma torch exhaust gas diagnostic for a plasma hearth furnace

Description: Real time monitoring of toxic metallic effluents in confined gas streams can be accomplished through use of Microwave Induced Plasmas to perform atomic emission spectroscopy, For this diagnostic to be viable it is necessary that it sample from the flowstream of interest in an isokinetic manner. A method of isokinetic sampling was established for this device for use in the exhaust system of a plasma hearth vitrification furnace. The flow and entrained particulate environment were simulated in th… more
Date: May 1, 1996
Creator: Pollack, B.R.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Preliminary Analysis and Simulation Results of Microwave Transmission Through an Electron Cloud

Description: The electromagnetic particle-in-cell (PIC) code VORPAL is being used to simulate the interaction of microwave radiation through an electron cloud. The results so far showgood agreement with theory for simple cases. The study has been motivated by previous experimental work on this problem at the CERN SPS [1], experiments at the PEP-II Low Energy Ring (LER) at SLAC [4], and proposed experiments at the Fermilab Main Injector (MI). With experimental observation of quantities such as amplitude, pha… more
Date: January 12, 2007
Creator: Sonnad, Kiran; Sonnad, Kiran; Furman, Miguel; Veitzer, Seth; Stoltz, Peter & Cary, John
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Method of inspecting dielectric materials at microwave frequencies

Description: A successful method of screening high-dielectric-constant, nonmagnetic, high-loss-factor materials at microwave frequencies was developed to provide material control by incoming inspection. This is accomplished by measuring the S parameters of the material---reliance on the manufacturer's permittivity data and x-ray examination for voids and inclusions is no longer necessary. Use of an automatic network analyzer makes 100% inspection economically feasible. (auth)
Date: November 1, 1973
Creator: O'Dell, G.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analysis and Measurement of Cross Talk in a Superconducting Cavity.

Description: A superconducting cavity used in a microwave gun requires that the launcher and the pickup probes be on the same side of the cavity, which causes direct coupling between them, or crosstalk. At room temperature, the crosstalk causes serious distortion of the RF response. This note addresses the phenomenon, the simulation results and the analysis, so that one can extract the desired information from the confusing signal.
Date: October 21, 2002
Creator: Zhao, Y.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Microwave processing of ceramic oxide filaments. Annual report, FY1997

Description: The objective of the microwave filament processing project is to develop microwave techniques to manufacture continuous ceramic oxide filaments. Microwave processing uses the volumetric absorption of microwave power in oxide filament tows to drive off process solvents, to burn out organic binders, and to sinter the dried fibers to produce flexible, high-strength ceramic filaments. The technical goal is to advance filament processing technology by microwave heating more rapidly with less energy … more
Date: December 31, 1998
Creator: Vogt, G.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Microwave technology for waste management applications including disposition of electronic circuitry

Description: Microwave technology is being developed nationally and internationally for a variety of environmental remediation purposes. These efforts include treatment and destruction of a vast array of gaseous, liquid and solid hazardous wastes as well as subsequent immobilization of selected components. Microwave technology provides an important contribution to an arsenal of existing remediation methods that are designed to protect the public and environment from undesirable consequences of hazardous mat… more
Date: September 1, 1995
Creator: Wicks, G. G.; Clark, D. E.; Schulz, R. L. & Folz, D. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Microwave concrete decontamination - Phase II results

Description: This report documents the results of the second phase of a four-phase development program to develop a system to decontaminate concrete using microwave energy. In the first phase of the program the feasibility of using microwaves to remove concrete surfaces was demonstrated. In the first phase experiments, concrete slabs were placed on a translator and moved beneath a stationery microwave system. The second phase demonstrated the ability to mobilize the technology to remove the surfaces from co… more
Date: June 1, 1994
Creator: White, T. L. & Foster, D. Jr.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High-Resolution Millimeter-Wave Imaging System for Defect Characterization in Dielectric Slabs

Description: Preliminary results are presented for a millimeter-wavelength free-space imaging system used to detect and characterize defects in layered dielectric composite slabs. Such systems throughout the microwave spectrum have shown great potential as alternative nondestructive evaluation tools for on-line, in-situ examination of low-loss dielectric materials such as plastics, ceramics, and various dielectric composites. Results of a fixed-frequency W-band imaging system operating in either through-tra… more
Date: August 1, 1994
Creator: Bakhtiari, S.; Gopalsami, N.; Raptis, A. C. & Lepper, M. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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REACTION MECHANISMS OF MAGNESIUM SILICATES WITH CARBON DIOXIDE IN MICROWAVE FIELDS

Description: The objective of the investigation was to determine whether microwave fields would enhance the reactions of CO{sub 2} with silicates that are relevant to the sequestration of carbon dioxide. Three sets of experiments were conducted. (1) Serpentine and CO{sub 2} were reacted directly at one atmosphere pressure in a microwave furnace. Little reaction was observed. (2) Serpentine was dehydroxylated in a microwave furnace. The reaction was rapid, reaching completion in less than 30 minutes. A detai… more
Date: February 18, 2004
Creator: White, William B.; Silsbee, Michael R. & Kearns, B. Joe
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Microwave processing of silicon carbide

Description: Reaction-bonded silicon carbide ({alpha}-SiC) armor tiles were annealed at 2100{degree}C using microwave radiation at 2.45 GHz. Ultrasonic velocity measurements showed that the longitudinal and shear velocities, acoustic impedances, and acoustic moduli of the post-annealed tiles were statistically higher than for the unannealed tiles. However, the exposed surfaces of the annealed tiles experienced slight degradation, which was attributed to the high annealing temperatures.
Date: December 31, 1994
Creator: Akerman, M. A.; Baity, F. W., Jr.; Caughman, J. B.; Forrester, S. C.; Morrow, M. S.; Holcombe, C. E., Jr. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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RF measurements of a traveling-wave muffin-tin accelerating structure at 90 GHz

Description: A measuring system at the table-top scale was developed for RF measurements of a muffin-tin accelerating structure operating at 32 times the SLAC frequency (2.856 GHz). Both perturbation and non-perturbation methods are employed to characterize the RF properties of a muffin-tin structure. Conventional bead pull measurements are extended to millimeter wavelengths. Design of the measuring system and preliminary results of RF measurements are presented.
Date: May 1, 1997
Creator: Chou, P.J.; Bowden, G.B.; Copeland, M.R.; Menegat, A.; Pritzkau, D.P.; Siemann, R.H. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Adhesive bonding via exposure to microwave radition and resulting mechanical evaluation

Description: Adhesive bonding/joining through microwave radiation curing has been evaluated as an alternative processing technology. This technique significantly reduces the required curing time for the adhesive while maintaining equivalent physical characteristics as the adhesive material is polymerized (crosslinked). This results in an improvement in the economics of the process. Testing of samples cured via microwave radiation for evaluation of mechanical properties indicated that the obtained values fro… more
Date: April 1, 1996
Creator: Paulauskas, F. L.; Warren, C. D. & Meek, T. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Rippled-beam free-electron laser

Description: The authors describe a new microwave generation mechanism involving a scalloping annular electron beam. The beam interacts with the axial electric field of a TM{sub 0n} mode in a smooth circular waveguide through the axial free-electron laser interaction, in which the beam ripple period is synchronous with the phase slippage of the rf mode relative to the electron beam. Due to nonlinearities in the orbit equation, the interaction can be made autoresonant, where the phase and amplitude of the ga… more
Date: October 1, 1997
Creator: Carlsten, B.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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