Research into the feasibility of thin metal and oxide-film capacitors Final technical report

Feasibility of producing thin metal and oxide- film capacitors with stable electrical properties in high temperature environment

Radiation effects design handbook. Section 3 - Electrical insulating materials and capacitors

Steady state radiation effects on electrical insulating materials and capacitors - handboo

The next detectors for gravitational wave astronomy

This paper focuses on the next detectors for gravitational wave astronomy which will be required after the current ground based detectors have completed their initial observations, and probably achieved the first direct detection of gravitational waves. The next detectors will need to have greater sensitivity, while also enabling the world array of detectors to have improved angular resolution to allow localisation of signal sources. Sect. 1 of this paper begins by reviewing proposals for the next ground based detectors, and presents an analysis of the sensitivity of an 8 km armlength detector, which is proposed as a safe and cost-effective means to attain a 4-fold improvement in sensitivity. The scientific benefits of creating a pair of such detectors in China and Australia is emphasised. Sect. 2 of this paper discusses the high performance suspension systems for test masses that will be an essential component for future detectors, while sect. 3 discusses solutions to the problem of Newtonian noise which arise from fluctuations in gravity gradient forces acting on test masses. Such gravitational perturbations cannot be shielded, and set limits to low frequency sensitivity unless measured and suppressed. Sects. 4 and 5 address critical operational technologies that will be ongoing issues in future detectors. Sect. 4 addresses the design of thermal compensation systems needed in all high optical power interferometers operating at room temperature. Parametric instability control is addressed in sect. 5. Only recently proven to occur in Advanced LIGO, parametric instability phenomenon brings both risks and opportunities for future detectors. The path to future enhancements of detectors will come from quantum measurement technologies. Sect. 6 focuses on the use of optomechanical devices for obtaining enhanced sensitivity, while sect. 7 reviews a range of quantum measurement options

Thermodynamic and transport properties of simple ionic melts

Imperial Users onl

Conceptual mechanization studies for a horizon definition spacecraft electrical power subsystem

Solar cell-battery electrical power subsystem for horizon definition spacecraf

Parts, Materials, and Processes Experience Summary

The ALERT program, a system for communicating common problems with parts, materials, and processes, is condensed and catalogued. Expanded information on selected topics is provided by relating the problem area (failure) to the cause, the investigations and findings, the suggestions for avoidance (inspections, screening tests, proper part applications), and failure analysis procedures. The basic objective of ALERT is the avoidance of the recurrence of parts, materials, and processed problems, thus improving the reliability of equipment produced for and used by the government

The principles and practice of the Xylophone Bar Magnetometer

PhD ThesisThis thesis reports on work undertaken to analyse, design, optimise, and fabricate a high-Quality factor mechanical resonant magnetometer, based on a Xylophone Bar Resonator (XBR). The principle of operation is based on the use of nodal supports to mechanically isolate a transverse beam vibrating in its fundamental mode. A control model is developed for the device, incorporating the effect of electromechanical parametric amplification. The device response and performance is shown to be strongly dependent on the Q factor of the sense element. The need for a quantitative model of XBR dynamics in order to design an optimal XBR is thus established. Using a Rayleigh-Ritz based approach, a model of the modal dynamics of an XBR is developed for the first time. In order to examine the efficacy of the nodal supports, a new model for support loss for resonators with two supports is developed and presented. Analytical models for other sources of dissipation are adapted for the first time to the XBR case. Combining these developments with a system level model allows for the development of a quantitative predictor of the fundamental and electronic noise limits on performance for an XBR. The model is solved over the operational range of geometric parameters, yielding optimisation criteria for the geometry. Corresponding predictions for the force and magnetic field sensitivity are presented. Based on the results, an optimised XBR design is exhibited for a macroscopic metal flexural XBM to be fabricated via Wire EDM. The fabricated devices are characterised, constituting the first demonstration of a macroscopic flexural XBR. The resulting Q factors and sensitivities are shown to be in agreement with the predictions. Fruitful directions for further work are suggested throughout the thesis and summarised in the conclusions. The original contribution to knowledge made by the thesis can be summarised as the development of an original and detailed theory of the principles of XBR optimisation for high Q, and demonstration of an operational macroscopic flexural XBM for the first time

Temperature effects in thin films of silicon oxide

Imperial Users onl

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

Dielectrics - Digest of literature, volume 28, 1964

Dielectric constants, dipole moments, relaxation times, conduction phenomena, insulating films, breakdown, materials, and applications of dielectrics - annotated bibliograph