WorldCat Identities


Works: 25 works in 51 publications in 1 language and 56 library holdings
Classifications: TK5103.5,
Publication Timeline
Study of adsorption of gases on solids in the high vacuum range( Book )

5 editions published between 1962 and 1965 in English and held by 9 WorldCat member libraries worldwide

Measurements of the adsorption of nitrogen on a polycrystalline tungsten wire and of carbon monoxide on molybdenum were continued (see AD-434 094). The saturation coverage of nitrogen on tungsten at room tempera ture was shown to be a function of the steady-state pressure and varies from 1 x 10 to the 14th power to 2.5 x 10 to the 14th power molecules/sq. cm. over the pressure range 10 to the -9th power to 10 to the -6th power torr. The adsorption of carbon monoxide on molybdenum at room temperature increases the work function of molybdenum over its initial value by 0.1 to 0.2 electron volts at saturation. (Author)
Studies of electron tube materials and thermionic emission processes( Book )

8 editions published between 1961 and 1963 in English and held by 8 WorldCat member libraries worldwide

The thermionic emission properties of ultra-pure nickel-base oxide cathodes in the clean test diode are being investigated. The sublimation from ultra-pure and N4 nickel-base barium oxide cathodes has been measured as a function of cathode temperature. The ion source was modified, resulting in an over-all sensitivity gain but slightly poorer resolution. The electron emission microscopy results previously observed for an ultra-pure nickel-base triple oxide cathode in a 21-inch diameter sealed-off emission microscope tube have been repeated under more or less identical experimental conditions in the demountable and constantly pumped tube in order to compare the operation of the cathode with that in a less favorable vacuum environment. The results are essentially the same. (Author)
Study of failure mechanisms in high power radio frequency generating devices( Book )

5 editions published between 1962 and 1964 in English and held by 5 WorldCat member libraries worldwide

The aim of this ivestigation is to determine failure mechanisms caused by residual gases in traveling-wave tubes and to study means of eliminating these gases in order to improve tube reliability. Gas spectra and electrical test data are shown for one tube operating at a severe life-test condition; correlation is made with tubes operating under a lower duty cycle. Gas ambient and gas sorption phenomena for tube components under operating conditions are presented for uncoated-cathode subassemblies and an oxide-coated cathode subassembly. In these subassemblies, the heater filament is the major gas source. (Author)
Semiconductor microwave amplitude and phase modulator( Book )

3 editions published in 1965 in English and held by 3 WorldCat member libraries worldwide

Experiments on the amplitude modulator indicate a linear falloff of modulation depth with drive frequency from 12.5 percent at 0.9 Gc/s to 8.4 percent at 1.4 Gc/s. It appears from these data that the useful modulation bandwidth of this device in its present configuration falls in the 1 Gc/s range. The drive power required to maintain a constant modulation index as the rf carrier power was varied over a three to one range was experimentally determined. A linear relation existed between the drive and carrier power levels. Measurements indicate that the injecting point contact can be represented by a series LCR circuit in shunt with the transmission line. On the basis of this circuit, it is possible to explain the observed decrease in insertion loss with forward bias. The stability of the GaAs varactors was improved by coating the semiconductor surface with a thin film of epoxy. However, the yield was limited, and some electrical deterioration occurred immediately after application of the epoxy coating. (Author)
Experimental study of factors controlling the effectiveness of high-temperature protective coatings for tungsten by C. D Dickinson( Book )

3 editions published between 1963 and 1965 in English and held by 3 WorldCat member libraries worldwide

The restrictions imposed by the processes of diffusion, evaporation, and coating substrate reactions on the choice of potential protective coating materials for tungsten were studied analytically and experimentally. The diffusive restriction is the most limiting and eliminates many refractory oxides with otherwise satisfactory attributes. The diffusive properties of rare earth sesquioxides and complex refractory oxides were explored by means of oxidation experiments and a layer growth experiment respectively. Mass spectrometric studies of the vaporization of refractory complex oxides were carried out to determine the applicability of the Wagner-Hauffe method of predicting vaporization rates. Provided certain thermodynamic approximations are valid and the vapor species over the complex oxide are the same as those over the pure component oxides, the predictions yield order of magnitude accuracy. A survey and exploration of reactions of possible coating materials with tungsten was performed emphasizing promising materials from the diffusion studies. (Author)
Development of improved gallium arsenide point contact varactor diodes for operation at x-band and above( Book )

1 edition published in 1962 in English and held by 2 WorldCat member libraries worldwide


2 editions published between 1965 and 1966 in English and held by 2 WorldCat member libraries worldwide

A program is being conducted to explore the application of known hot-carrier effects in semiconductors to the development of new and improved microwave devices. The devices being investigated include modulators, mixers, harmonic generators, and detectors. An experimental technique was developed for measuring the modulation depth of the hot-carrier amplitude modulator at drive frequencies above 0.5 Gc/s. Typically, modulation indices of 60 and 30 percent were obtained at 0.5 Gc/s and 0.75 Gc/s respectively. The hot-carrier InSb mixer exhibited a minimum detectable signal power of -96 dBm at 70 Gc/s with a local-oscillator drive of -4 dBm at 78?K. Third-harmonic power at 210 Gc/s was obtained with a p-type 35 ohm cm Ge hot-carrier unit. Hot-carrier detectors fabricated from 0.5 ohm cm p-type Ge exhibited essentially square-law response for power levels up to 10 mW at 70 Gc/s. The sensitivity of the units is greater than 100 mV/mW. (Author)
Nonlinear semiconductors at millimeter frequencies( Book )

2 editions published in 1965 in English and held by 2 WorldCat member libraries worldwide

Measurements of the noise figure of an experimental 70-Gc/s receiver incorporating InSb hot-carrier mixers at 77 K were undertaken. The initial results indicate that the noise figure of this receiver is approximately 6 dB higher than that of the same receiver using a Schottky barrier mixer at room temperature. A 70-Gc/s hotcarrier detector was designed and constructed which exhibited square-law behavior for rf power levels up to 5 mW. A reliable experimental technique for measuring the characteristics of the hot-carrier modulator at uhf was established. Measurements on a typical unit yielded modulation indices of 80 percent at 220 Mc/s and 40 percent at 400 Mc/s. The insertion loss of the modulator was 4.5 dB. (Author)
Study of thin film compounds formed from simultaneously evaporated constituents( Book )

2 editions published between 1962 and 1965 in English and held by 2 WorldCat member libraries worldwide

Thin films of lead titanate suitable for forming thinfilm capacitors have been prepared by the simultaneous evaporation of lead and titanium oxides in an oxygen atmosphere. The experimental conditions for deposition of the films on silicon substrates have been established for obtaining virtually a 100 percent yield of films with a specific capacitance greater than 1 micro F/sq cm, dielectric constants in the range from 200 to 400, and a dissipation factor less than 10 percent. This high reproducibility derives from an improved understanding and control of the vapor-phase oxidation of titanium and of the interactions between the dielectric film and the metal electrodes. The current procedure for synthesis of the lead titanate films is given in detail. An Appendix provides a survey of the literature on previous work on highdielectric-constant films with the perovskite structure. (Author)
Hot carrier phenomena in semiconductors at microwave frequencies( Book )

2 editions published in 1962 in English and held by 2 WorldCat member libraries worldwide

Measurements of recombination in Cu- and Ni- doped Ge, using contact injection, were made and corrected for surface recombination. The data for Ge:Ni at room and dry ice temps. are similar; for Ge:Cu they are different in that lifetime first increases with field, then decreases at the low temp. Throughout this temp. range, the following appear to be established; (1) the electron capture cross section for neutral Ni and neutral Cu decreases rapidly with electron speed; and (2) for Cu( - ) it is essentially independent of speed. The difference in speed-dependence of neutral and negatively-charged centers seems attributable to the Coulomb barrier of the latter. Complex conductivities of n-Ge are reported for 3 samples in different orientations and comparable dc resistivites at 78k. For n-InSb at 78k, large negative values of dielectric constant were found. (Author)

2 editions published between 1962 and 1963 in English and held by 2 WorldCat member libraries worldwide

The theoretical performance of an idealized equivalent mixer circuit, with short-circuited image impedance and positive output impedance, is characterized by expressions for conversion gain, mixer noise figure, system noise figure, input and output impedance, and the signal source impedance required for minimum noise figure. The results of a typical numerical computation of these quantities are displayed graphically as a function of the local oscillator amplitude, with the bias fixed slightly below the peak voltage, in the positive conductance region. The experimental program has begun with tests of the i. f. portion of the mixer. (Author)
High-Energy Pulsed Liquid Laser( Book )

2 editions published between 1967 and 1968 in English and held by 2 WorldCat member libraries worldwide

The study of high-energy liquid lasers was approached from three aspects: device, material, and optical. Two systems for circulation of the liquid medium in an operating laser were designed and constructed, and one was operated successfully. Problems concerning the optical homogeneity of the laser solution and mechanical abrasion of the pump parts remain to be solved. Most problems of materials preparation were overcome and high-quality solutions can now be prepared reproducibly. Spectroscopic and optical measurements were made, and the transition cross-section for the laser emission was calculated. The emission of the laser was studied in terms of energy output, spectral line breadth, divergence, amplification, and a new phenomenon, self Q-switching. (Author)
Investigation of photoconductor materials for a solid-state sonar display( Book )

2 editions published between 1964 and 1965 in English and held by 2 WorldCat member libraries worldwide

The purpose of this contract is to develop and construct a solid-state sonar display of variable persistence. The display device utilizes a layer of electroluminescent material to generate the output light and a control layer of photoconductive material which accepts an input illumination from a servo-driven wand. An opaque enamel layer between the other two layers is used to prevent optical coupling between the display output light or ambient illumination and the control photoconductor. Full-size display panels with the 50 range elements and 36 angular positions have been constructed. The photoconductor was sintered onto the panels in a specially designed two-zone furnace. Good brightness and brightness-decay uniformity have been achieved. Decay to one tenth of original brightness of 9 sec maximum and 250 ms minimum were obtained. The filter circuits of the Government-furnished equipment were tuned and the whole system performance was evaluated with an input generated by two types of simulators. One of the simulators was synchronous and generated an input which produced a fixed pattern on the display panel. A second simulator produced a constantly changing trace on the display. Both of these tests confirmed earlier predictions that the bandwidth of the filters did not permit a single element output on the panel. (Author)
A solid-state self-scanning display device. Prepared for: Rome Air Development Center, Air Force Systems Command, U.S. Air Force by M. S Wasserman( Book )

1 edition published in 1962 in English and held by 1 WorldCat member library worldwide

Materials are investigated for use in a solidstate electroluminescent display device in which the electric field for activation of the electroluminescent layer is provided by elastic waves propagated through a piezoelectric ceramic plate which serves as the substrate for the display. The work was subdivided into a search for piezoelectric ceramics with improved properties for use as the display substrate and the input transducers, the development of procedures for fabrication of thin large-area piezoelectric ceramic plates, and a search for materials for improved nonlinear resistor layers for the suppression of spurious light in the display. (Author)

1 edition published in 1964 in English and held by 1 WorldCat member library worldwide

This report describes a project (1) to determine changes that occur in the composition of the gas during operation of a discharge tube such as is used in helium-neon lasers, and (2) to develop suitable instrumentation for such investigations. The omegatron mass spectrometer system that was developed is described, and data obtained with it on a helium-neon laser are reported. The laser output power and intensities of some lines of the emission spectrum of the discharge are also reported as functions of time of continuous operation of this laser. (Author)

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

The investigation of chelate lasers has as its objective the evaluation of the potentialities of liquid lasers and the analysis and improvement of their performance. Toward this end, the work was designed to proceed along two parallel and complementary lines: an investigation of the chemical properties of the materials, in terms of the requirements for laser action; and an investigation of the physical properties of the chelate laser itself, in terms of the design and improvement of the laser cavity and associated equipment. The report summarizes previous work and describes in detail the progress on these lines in the past year. A full-length paper entitled 'Spectroscopy and coordination chemistry of europium chelate solutions: concentration and solvent effects' is included as an appendix
Investigation of refractory compounds as thermionic emitters( Book )

1 edition published in 1962 in English and held by 1 WorldCat member library worldwide


1 edition published in 1962 in English and held by 1 WorldCat member library worldwide

Study of fail ee mechanisms in high power radio frequency generating devices( Book )

1 edition published in 1962 in English and held by 1 WorldCat member library worldwide

This investigation undertakes to determine the causes of failures in gridded power traveling wave tubes. The gas ambient of two types of operating tubes and of individual tus sub assemblies and components are examined with an omegatron mass spectrometer permanently attached to the unit under test. Background gas ambients in envelopes containing only omegatrons are used as controls and are presented. Electrical test parameters of the traveling-wave tube in re lation to its gas ambient are presented and correlations are made with cathode activity decrease and power output decrease as functions of integrated partial gas pressures in th ating tube. Contributions made by various proc essed tube components to the gas ambient of the operating vacuum tube are presented and discussed. (Author)
Thin films formed by electrochemical reactions( Book )

1 edition published in 1962 in English and held by 1 WorldCat member library worldwide

The preparation of several hundred thin-film Ta capacitors confirmed previous findings that the type of glass and the cleaning procedure used were necessary for obtaining high-quality capacitors. With the preparation of a large number of capacitors, data have been obtained on the uniformity of capacitance values. Improvements in both uniformity and electrical characteristics resulted from a reduction of the substrate temperature during tantalum sputtering, from the treatment of the sputtering mask and from spectroscopic monitoring for impurities in the glow discharge. The evaluation of electrical properties was extended to cover a range of frequencies and temperatures. The preparation of thin-film resistors by anodization of sputtered and vacuumevaporated Ta was accomplished. Resistance was reproducible to within 0.3% of the desired value. The films were evaluated for power dissipation, and the temperature coefficient of resistance was determined as a function of sheet resistivity and film thickness. (Author)
moreShow More Titles
fewerShow Fewer Titles
Audience Level
Audience Level
  Kids General Special  
Audience level: 0.98 (from 0.91 for A solid-st ... to 1.00 for Studies of ...)

English (46)