Vacuum Capacitor Research Articles

Stable cryogenic vacuum capacitor for single-electron charging experiments

For use in our single-electron charging experiment, a novel cryogenic vacuum capacitor has been developed which is superior to the previous parallel-plate design. Due to its coaxial design consisting of a long cylindrical center electrode and a shorter cylindrical ring electrode, it is inherently stable against mechanical vibrations and thermal cycling. Electrical insulation is achieved by the exclusive use of sapphire, which promises extremely low leakage currents.

Wide dynamic range silicon diaphragm vacuum sensor by electrostatic servo system

A wide dynamic range silicon diaphragm vacuum sensor by an electrostatic servo system and an electrical circuit for servo control have been made. In nonservo mode, i.e., when the sensor was used as a capacitive vacuum sensor, a linear characteristic between pressure and output voltage was obtained in the pressure range from 0.1 to 100 Pa. On the other hand, the square root of the servo voltage was proportional to the pressure in a wide pressure range from 0.1 to 530 Pa in servo mode. The servo mechanism is effective for widening the dynamic range of vacuum sensors.

The structures for electrostatic servo capacitive vacuum sensors

Abstract Two kinds of electrostatic servo capacitive vacuum sensors have been successfully fabricated using P++ silicon etch-stop and vacuum anodic-bonding techniques. In order to maintain the reference cavity at high vacuum, a non-evaporable getter (NEG) is used as a small vacuum pump. The dynamic range of the sensor can be extended by a servo system. The pressure responses of the sensors are good. The plot of servo voltage versus pressure is measured and the theoretical data agree with the experimental results.

Vacuum-sealed silicon micromachined pressure sensors

Considerable progress in silicon pressure sensors has been made in recent years. This paper discusses three types of vacuum-sealed silicon micromachined pressure sensors that represent the present state of the art in this important area. The devices are a capacitive vacuum sensor, a surface-micromachined microdiaphragm pressure sensor, and a resonant pressure sensor. Vacuum sealing for these devices is accomplished using anodic bonding, films deposited using low-pressure chemical vapor deposition, and thermal out-diffusion of hydrogen, respectively. These sensors emphasize high sensitivity, small size, and excellent stability, respectively. The silicon-diaphragm vacuum sensor uses electrostatic force balancing to achieve a wide pressure measurement range.

Silicon micromachining for integrated microsystems

Abstract Small sized but relatively complicated intelligent systems or subsystems were fabricated based on silicon micromachining. Packaged micromechanical sensors as extremely sensitive resonant sensors, accelerometers and a silicon diaphragm capacitive vacuum sensor were developed. A two-dimensional electromagnetic optical scanner was also developed. The vacuum pressures in the packaged cavities of these devices were well controlled. Microflow control systems which have bakable microvalves were fabricated for advanced semiconductor processes. Novel three-dimensional micro fabrication methods were developed for silicon micromachining.

Vacuum packaging for microsensors by glass-silicon anodic bonding

Abstract Vacuum packaging by the glass-silicon anodic process is studied. The residual gas generated during the anodic binding process and that desobed from the silicon and glass surface increase the pressure in a sealed cavity. In order to fabricate a vacuum sealed cavity, two methods are proposed to eliminate the residual gas; (i) the residual gases are evacuated through a small opening after bonding and then the opening is plugged by depositing a material in vacuum, (ii) the residual gases are absorbed by a getter inside the sealed cavity. A non-evaporable getter (NEG) is used for the second method. A vacuum sealing of tens of Torr is obtained by the firat method. The second method and a combnation of the two methids enables vacuum sealing at a pressure lower than 10-5Torr. A prototype of a capacitive vacuum sensor is fabricated by using the second method.

A simple relativistic paradox about electrostatic energy

A charged parallel-plate vacuum capacitor moves uniformly through an inertial frame. Its field energy alone does not transform according to the familiar law ‘‘energy=γ× rest energy.’’ However, when the stresses in the supports are taken into account, the entire system does satisfy this relation.

Some dynamical properties of very strong double layers in a triple plasma device

We present experimental results on three dynamic properties of very strong double layers observed in a triple plasma device. First, it is observed that when an inductance of sufficient size is inserted in series with the external bias supply used to produce the double layer, disruptions in the plasma current occur accompanied by disruptions in the double layer potential. Second, it is observed that with all external reactances reduced as much as possible, a sort of jitter-motion occurs in the position of the double layer around its equilibrium position. Third, when the external bias supply is pulsed, the initial potential distribution is observed to have an essentially uniform slope, as in the case of a vacuum capacitor. The disruption phenomenon may be explained in terms of the behavior of the potential structure as a function of the bias voltage and this explanation is discussed along with the experimental evidence for its validity. A comparable understanding of the other two phenomena has not been achieved, but in both cases there are qualitative differences between the behavior reported here and what has been observed in Q-machines and these differences are discussed.

Analysis of the components of the error of capacitive vacuum gauges

Analysis of the components of the error of capacitive vacuum gauges

An electrical method for the measurement of thermal expansion of thin films

A two-terminal capacitance method has been devised to measure the coefficient of linear thermal expansion ( alpha ) of thin films as conventional methods are unsuitable. The formula to evaluate the observed value of the thermal expansion coefficient ( alpha obs) has been obtained and the relevant correction factor has been incorporated in the final formula alpha true= alpha obs+ alpha el where alpha el and alpha true are the thermal expansion coefficients of electrode film and sample thin film respectively. The design of the dilatometric cell, the preparation of the thin-film specimen and the electrode film configuration are described. The change in capacitance with temperature of the vacuum capacitor, where the specimen film is the spacer, is used to evaluate alpha obs. This technique has been standardised using thin platelets ( approximately 100 mu m) of a single crystal of NaCl. The other considerations which are important for the precision of this measurement technique are also discussed.

Modified vacuum capacitor

Abstract The paper presents a brief account of the behaviour of a new type of vacuum capacitor, in which the conventional plate is replaced by a conducting film. It consists of two aluminized concentric glass tubes, outer one internally and inner one externally sealed off at both ends. Construction details, rating characteristics, effect of humidity and temperature changes are discussed. The fabricated experimental capacitors of value 50 pF were found to withstand 1 kV, above which vacuum breaks down as predicted by clump theory. The advantages and disadvantages of this capacitor over conventional vacuum capacitors are discussed.

A fused‐quartz tubular vacuum capacitor

Electrical Engineering in JapanVolume 94, Issue 4 p. 37-41 Article A fused-quartz tubular vacuum capacitor T. Igarashi, T. Igarashi Electrotechnical Laboratory, Ministry of International Trade and IndustrySearch for more papers by this authorM. Kanno, M. Kanno Electrotechnical Laboratory, Ministry of International Trade and IndustrySearch for more papers by this authorR. Fukushima, R. Fukushima Electrotechnical Laboratory, Ministry of International Trade and IndustrySearch for more papers by this author T. Igarashi, T. Igarashi Electrotechnical Laboratory, Ministry of International Trade and IndustrySearch for more papers by this authorM. Kanno, M. Kanno Electrotechnical Laboratory, Ministry of International Trade and IndustrySearch for more papers by this authorR. Fukushima, R. Fukushima Electrotechnical Laboratory, Ministry of International Trade and IndustrySearch for more papers by this author First published: 1974 https://doi.org/10.1002/eej.4390940407AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume94, Issue41974Pages 37-41 RelatedInformation

溶融水晶管形真空コンデンサ

溶融水晶管形真空コンデンサ

A microwave cavity for high power ENDOR spectroscopy

A rectangular cavity for 3 cm wavelength is described, in which the radio-frequency coil is formed by part of the wall of the cavity. The microwave Q is about 5000 whereas the Q of the RF circuit, made up by the single loop coil and a tunable vacuum capacitor, is about 50.

Modern trends in high-frequency transmitter design

The operating costs of a transmitting station can be substantially reduced if the equipment is automatically tuned and all services are directly controlled from a central point. This is due to the reduction of operating staff covering three shifts, and to the saving in ‘off the air’ time made possible by rapid change of frequency.The paper describes a range of transmitters with output powers up to 85kW which have completely automatic control of tuning, coupling and gain. The transmitters are of the linear-amplifier type, and hence are suitable for all forms of service used in h.f. communication, when associated with the appropriate signal source. In particular, the paper describes the automatic control system of the transmitter.Various aspects of performance are discussed, including the design requirements for low distortion and for the reduction of spurious and harmonic emissions.If the saving in operating costs is to be fully realized, a high standard of reliability is necessary. The types of components used are described. They include variable vacuum capacitors, variable inductors, silicon rectifiers and vapour-cooled valves.

Electric Characteristics of Vacuum Capacitor and Results its' Improvement

Electric Characteristics of Vacuum Capacitor and Results its' Improvement

Development of vacuum capacitors

Vacuum capacitors are particularly suitable for high-frequency high-voltage operation in airborne radio equipment. Capacitors developed to fulfil requirements of a specific nature revealed a number of interesting effects which are explained qualitatively, and which have considerable influence on the capacitor design. The results are of general application and tests on the capacitors developed show that their performance is very satisfactory. It is believed that, for the requirements specified, no other type of capacitor has a comparable performance.

Development of vacuum capacitors

Development of vacuum capacitors

Vacuum Capacitors

This paper describes the properties, characteristics, and uses of the vacuum capacitor. The constructional details of two General Electric vacuum capacitors, the GL-1L38 and the GL-1L22, are discussed. Design considerations are discussed from the viewpoint of both the designer and the manufacturer. Capacitance formulas are given, and the equation for energy loss is derived. Operating characteristics and ratings of the vacuum capacitor are considered, and the effects of humidity, temperature, and vibration are noted. The advantages of the vacuum capacitor are thoroughly discussed and the applications which are brought about because of these advantages are described.