WorldCat Identities


Works: 25 works in 51 publications in 1 language and 59 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

The work function of polycrystalline tungsten was measured, using the retarding field technique, as a func tion of the exposure to a carbon monoxide ambient. The work function was found to vary from 4.4 eV to 5.2 eV in going from an initially clean surface to one saturated with carbon monoxide. The successive adsorption of oxygen on a tungsten surface already saturated with carbon monoxide is inferred from the work-function data. The increase in work function (from 5.2 eV to 6.4 eV) is indicative of possibly a monolayer or more of adsorbed oxygen. The work functions for a clean (111) silicon surface, silicon exposed to 0.000003 torr-sec oxygen, and silicon exposed to 0.000009 torr-sec oxygen were found by the retarding field method to be 4.79 eV, 5.02 eV and 5.07 eV, respectively. (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 Ni based oxide cathodes in the clean test diode were investigated. The effects of the following processing, activation and life conditions on thermionic emission were evaluated: (1) improvement in the cleanliness of the diode system by pre-processing the bulb, stem and supporting elements prior to final assembly of the test diode; (2) dependence of the electrolytic activation process on cathode temperature, anode voltage and anode current; (3) operation of the test diodes during life both with and without anode voltage. The method which was developed for measuring the evaporation of active material from dispenser cathodes was extended to the more difficult problem of measuring sublimation of active material from oxide cathodes. Preliminary results on the evaporation of Ba and/or BaO were obtained for the following passive and active metal base oxide systems; BaO on Pt; BaO on ultra-pure Ni rod; BaO on active N4 Ni; BaO on Ta; C-10 triple oxide coating on ultra-pure Ni; C-10 on N4 Ni. (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 6 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)
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

Oxidation at elevated temperatures of Zr-Th, Zr-Y, Hf-Y, Hf-W, Hf-W-Re, Al-Cr-Sn, and Al-LaSn alloys, as well as ZrN, HfN and ZrN-ThN combinations was studied in order to clarify specific aspects of the problem of protecting W against oxidation at high temperatures. Experimental results showed that there was much less tendency for ZrO2, ThO2 and HfO2 scales to crack during growth at high than at low temperatures. Multiphased scales were more resistanct to spalling than single-phased scales, and protective oxides were grown many alloys. However, even in sound and coherent scales composed of these oxides, O diffused so rapidly that it is doubtful that they could form the basis of a protective system at 2000 C. (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 were extended into the uhf range. Typical measurements on experimental epitaxial silicon diodes yielded modulation indices of approximately 50 percent at 220 Mc/s and approximately 15 percent at 400 Mc/s. This decrease in modulation depth with increasing modulation frequency appears to be due to the frequency sensitivity of the wafer in which the diode is mounted. A new test structure has been designed which will enable a more accurate and reliable measurement of the equivalent circuit parameters of the PIN diode at 70 Gc/s. This unit is presently being fabricated. An experimental method was established for tuning the varactor phase shifter for maximum phase shift. This condition of tuning does not correspond to minimum insertion loss. In the 70-Gc/s hybrid ring configuration 50 degrees of phase shift was obtained with a 3.4 dB insertion loss. A method for coating the surface of the point-contact GaAs varactors with a thin epoxy film was developed in an effort to improve varactor stability. Initial tests on fourteen diodes treated in this manner show promising results. (Author)
Nonlinear semiconductors at millimeter frequencies( Book )

2 editions published in 1965 in English and held by 3 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)
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)
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

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)
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)

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)

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. Modulation indices of redesigned hot-carrier amplitude modulators were measured up to modulation frequencies of 1600 MHz. Three units exhibited modulation indices between 30 and 55% at 1600 MHz, and between 70 and 75% at 250 MHz. A fourth unit exhibited essentially the same modulation depth at 1600 MHz as at 250 MHz, i.e., approximately 80%. An evaluation of hot-carrier mixer sensitivity using various high-quality InSb semiconductor samples and several fabrication techniques is summarized. Experimental data are presented on the conversion loss and i.f resistance of the cooled InSb hot-carrier mixer as a function of local oscillator power level. The i.f. resistance of a hot-carrier mixer and a Schottky barrier mixer are compared as a function of local oscillator power. A theoretical analysis is presented which extends the range of validity of the so-called dc incremental method and the amplitude modulation method of measuring the conversion loss of a mixer. With peak input power on the order of 100 watts, the conversion efficiency of the harmonic generator is approximately -60 dB. (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

The possibility of achieving amplification of microwaves by means of hot electrons in InSb with an applied magnetic field was investigated with the use of the simple model of the and structure. Preliminary results indicate the possibility of obtaining amplification of circularly polarized plane microwaves using a bulk semiconductor such as InSb with two carriers and steady axial magnetic and electric fields. Probe measurements were made to detect phonons emitted by hot electrons in adjacent field-free regions in n-type Ge. High levels of spurious voltage pickup masked any phonon-drag effect that may have been present. small-signal measurements of conductivity and dielectric constant at 69.25 kmc as functions of dc bias field were made on one InSb sample. Very strong field dependence was observed, and it appears that this material may be appicable to variable-reactance devices at submillimeter wavelengths. Largesignal experiments were also performed in which the InSb sample was made to function as a bolometer-type peak power detector at 69.25 kmc. A hot-carrier mixer was constructed which will be used to measure the extent to which the heating of the carriers follows the field at 24 kmc. (Author)
A solid-state self-scanning display panel( Book )

1 edition published in 1964 in English and held by 2 WorldCat member libraries worldwide

The solid-state self-scanning display device described in this report consists basically of a piezoelectric ceramic plate which controls the point-by-point excitation of an electroluminescent phosphor layer over the plate. An investigation has been carried out for the optimization of materials and structures employed in the panel. This investigation included the electroluminescent phosphor layer, a nonlinear resistor layer used to obtain high contrast and the piezoelectric ceramic distributor with its input transducer. Techniques for coupling the different planar display components are described. An experimental model of the display panel employing the results of this investigation was constructed. Contract specifications for the model have been met or exceeded. A drive circuit for testing the display panel is described in detail. A recommendation for significantly improving the device is presented. (Author)
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)
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 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
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)
moreShow More Titles
fewerShow Fewer Titles
Audience Level
Audience Level
  Kids General Special  
Audience level: 0.98 (from 0.90 for A solid-st ... to 1.00 for Studies of ...)

English (46)