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Microwave Spectral Tables: Volume 3. Polyatomic Molecules With Internal Rotation

Description: From Introduction: "This volume contains data on the microwave spectra of 94 polyatomic molecules capable of exhibiting internal rotation, based upon a search of the literature up to July, 1962, but including some information of later dates."
Date: June 1969
Creator: Wacker, Paul F.; Cord, Marian S.; Burkhard, Donald G.; Petersen, Jean D. & Kukol, Raymond F.
Partner: UNT Libraries Government Documents Department

BOLOVAC Systems for Measuring Electrical Quantities From 0.5 MHz Through Microwaves

Description: From Introduction: "This paper describes in some detail how Bolovac works, when its structural components are, what are the methods and steps of the procedure in its various major applications, and reasons for its advantages. The emphasis is on applications. Present status at the National Bureau of Standards relating to fabricating the most important component of the Bolovac-the bolometric disk-is briefly pointed out."
Date: January 1972
Creator: Selby, Myron C.
Partner: UNT Libraries Government Documents Department

Microwave Diagnostic Systems and Techniques for Use in Controlled Fusion Research

Description: Abstract: "Microwaves have been used for several years at Lawrence Radiation Laboratory to study conditions in the magnetically contained plasmas of controlled fusion research. There are two basic microwave techniques. One gives information on electron density and distribution in the plasma, the other provides data on electron temperature. This paper briefly summarizes the established techniques, discusses engineering requirements and limitations, and describes some further applications of microwaves presently being considered."
Date: June 1960
Creator: Bunn, Harlin L.
Partner: UNT Libraries Government Documents Department

Microwave Diagnostics for High-Temperature Plasmas

Description: This report presents the high-temperature plasma research, aimed mainly toward controlled thermonuclear reactions, that have been greatly facilitated by the development of a number of microwave diagnostics, based on previous plasma microwave studies but mostly on ideas generated at UCRL in conjunction with the AEC Project Sherwood.
Date: March 1957
Creator: Wharton, Charles B.
Partner: UNT Libraries Government Documents Department

Microwave Diagnostics in ARC Research : On Determination of Physical Quantities of Gas Discharges in Ion-containment Machines by Measurement of Microwave Propagation Coefficient

Description: This report describes a method used to determine semi-quantitatively the time-varying plasma density in magnetic mirror machines by microwave phase-shift and attenuation measurement.
Date: April 1955
Creator: Post, Richard F.; Prosser, T. F. & Wharton, C. B.
Partner: UNT Libraries Government Documents Department

Interaction of Microwaves and Germinating Seeds

Description: This investigation was concerned with determining the interaction of microwaves with germinating seeds. This study covers two different approaches. The preliminary efforts covered the response of germinating seeds to treatment by microwaves and heat. The second phase of the investigation used microwaves as a probe to determine some of the processes of early seed germination. The preliminary investigation measured the internal metabolic process by ATP production. Leakage of ions and organic material from germinating seeds indicated that membranes are a target of microwaves and heat. Electron photo-micrographs showed an increase in damage to membranes as heat and microwave treatments were increased. The second phase of this investigation was concerned with determining some of the biological activity at the initiation of germination of wheat seeds, Triticum aestivum L., using a resonating microwave cavity oscillating at 9.3 GHz as a probe. Direct current conductivity measurements were also made on the seeds as a means of confirming the observations made with the microwave cavity. There was no observable difference between treatment by UHF or heat in the ultrastructure of germinating seeds. A dielectric response far above that of free water was found as live seeds of wheat began to imbibe water. This effect was assumed to be due to the release of ions, because conductivity increased as corresponding quantities of water were imbibed; and both conductivity and dielectric response decreased as imbibition progressed. Although dead seeds also imbibe water, they do not show this decrease in dielectric response. The dielectric response of live seeds was reduced after the initial imbibition, showing that water became tightly bound as imbibition progressed. The dielectric response of actively growing shoots from the seeds was much less than that of the seeds themselves. The large quantity of water in the shoots is assumed to be immobile, being tightly ...
Date: August 1987
Creator: Shafer, Floyd L. (Floyd Lorenz)
Partner: UNT Libraries

Microwave Attenuation Standards and Measurements

Description: Report discussing microwave attenuation measurement methods and standards. In addition, a relatively new and more precise way of representing and analyzing an attenuation measurement is presented. This in turn permits more rigorous definitions and error analyses than were previously possible. The referral of microwave attenuation measurements to standards operating at lower frequencies is discussed with particular attention to the errors in the referral processes as well as the errors in the standards themselves. Desirable characteristics are listed for attenuators which are suitable for calibration. Measurement methods are classified and described. Comments are made on the accuracy and convenience of various methods, and references are given which cover most of the basic and important research in this field. Key words: Microwave, attenuation, measurements, standards, tutorial.
Date: April 3, 1967
Creator: Beatty, Robert W.
Partner: UNT Libraries Government Documents Department

A study of transient molecular ions using a resonant microwave cavity as a probe

Description: The microwave-resonant-cavity technique was employes as a probe to determine the presence of molecular ions of helium in a d.c.-discharge, helium-plasma filament placed coaxially in a TM010 mode cavity. The cavity-resonance profile was displayed on an oscilloscope, and the nature of the perturbation of this resonance was used to determine the nature of the ions present in the plasma stream.
Date: December 1973
Creator: Congleton, Michael William
Partner: UNT Libraries

Some Microwave Studies of Gaseous Plasmas

Description: A Lecture Delivered at Sandia Corp., Albuquerque, N. Mex.. April 8, 1959. The type and nature of plasmas considered are defined, and it is shown that significant results are quite general and can be applied to large classes of plasmas. The physical phenomena are emphasized at the expense of the mathematics. (W.D.M.)
Date: July 1, 1959
Creator: Goldstein, L.
Partner: UNT Libraries Government Documents Department

Microwave Interferometer Measurements for the Determination of Plasma Density Profiles in Controlled Fusion Experiments

Description: The following report demonstrates experimental verification of a method described in a previous paper--that involves measuring the dispersive microwave propagation coefficients simultaneously at several frequencies and comparing measured values with the values calculated for various distribution functions--and describes the procedure used to determine the distribution function in a sample laboratory plasma experiment.
Date: November 6, 1958
Creator: Wharton, Charles B. & Slager, Donald M.
Partner: UNT Libraries Government Documents Department

Carbon Nanotube/Microwave Interactions and Applications to Hydrogen Fuel Cells.

Description: One of the leading problems that will be carried into the 21st century is that of alternative fuels to get our planet away from the consumption of fossil fuels. There has been a growing interest in the use of nanotechnology to somehow aid in this progression. There are several unanswered questions in how to do this. It is known that carbon nanotubes will store hydrogen but it is unclear how to increase that storage capacity and how to remove this hydrogen fuel once stored. This document offers some answers to these questions. It is possible to implant more hydrogen in a nanotube sample using a technique of ion implantation at energy levels ~50keV and below. This, accompanied with the rapid removal of that stored hydrogen through the application of a microwave field, proves to be one promising avenue to solve these two unanswered questions.
Access: This item is restricted to the UNT Community Members at a UNT Libraries Location.
Date: May 2004
Creator: Imholt, Timothy James
Partner: UNT Libraries

Preliminary Results of a Determination of Temperatures of Flames by Means of K-Band Microwave Attenuation

Description: "The temperature effects on the attenuation of K-band microwaves, at a frequency of 26,500 plus or minus 30 megacycles per second, through natural-gas and propane flames containing added alkali halide salts, were investigated over a temperature range from 1900 to 2500 K. The preliminary data of this investigation indicated that the attenuation varies appreciably with the sodium-line-reversal temperatures of the flames and is independent of the particular hydrocarbon fuels that were used for temperature sources and of the particular halide components of the compounds used in the concentrations employed to produce easily measurable attenuation. A reproducibility of plus or minus 25 K was obtainable" (p. 1).
Date: September 24, 1951
Creator: Rudlin, Leonard
Partner: UNT Libraries Government Documents Department

Measurement of Turbulence Decorrelation during Transport Barrier Evolution in a High Temperature Fusion Plasma

Description: A low power polychromatic beam of microwaves is used to diagnose the behavior of turbulent fluctuations in the core of the JT-60U tokamak during the evolution of the internal transport barrier. A continuous reduction in the size of turbulent structures is observed concomitant with the reduction of the density scale length during the evolution of the internal transport barrier. The density correlation length decreases to the order of the ion gyroradius, in contrast to the much longer scale lengths observed earlier in the discharge, while the density fluctuation level remain similar to the level before transport barrier formation.
Date: March 29, 2005
Creator: Nazikian, R.; Shinohara, K.; Kramer, G.J.; Valeo, E.; Hill, K.; Hahm, T.S. et al.
Partner: UNT Libraries Government Documents Department

2-D Imaging of Electron Temperature in Tokamak Plasmas

Description: By taking advantage of recent developments in millimeter wave imaging technology, an Electron Cyclotron Emission Imaging (ECEI) instrument, capable of simultaneously measuring 128 channels of localized electron temperature over a 2-D map in the poloidal plane, has been developed for the TEXTOR tokamak. Data from the new instrument, detailing the MHD activity associated with a sawtooth crash, is presented.
Date: July 8, 2004
Creator: Munsat, T.; Mazzucato, E.; Park, H.; Domier, C. W.; Johnson, M.; Luhmann, N. C., Jr. et al.
Partner: UNT Libraries Government Documents Department

Laboratory Characterization of an Imaging Reflectometer System

Description: While microwave reflectometry has proven to be a sensitive tool for measuring electron density fluctuations in many circumstances, it has also been shown to have limited viability for core measurements and/or conditions of strong turbulence. To this end, a new instrument based on 2-D imaging reflectometry has been developed to measure density fluctuations over an extended plasma region in the TEXTOR tokamak. Laboratory characterization of this instrument has been performed using corrugated reflecting targets as an approximation to plasma reflections including 2-D turbulent fluctuations of various magnitude and poloidal wavenumber. Within this approximation, the imaging reflectometer can recover the spectral and spatial characteristics of the reflection layer lost to or otherwise inaccessible to conventional techniques.
Date: January 14, 2003
Creator: Munsat, T.; Mazzucato, E.; Park, H.; Domier, C.W.; Jr., N.C. Luhmann; Donne, A.J.H. et al.
Partner: UNT Libraries Government Documents Department