Showing papers in "Vacuum in 1978"

TL;DR: Machinable glass-ceramic is a new class of ceramic material which is capable of being machined to precise tolerances using conventional metal-working tools and equipment as discussed by the authors.

TL;DR: In this paper, a series of experiments on the trapping and release of the inert gases neon and argon at low energies (low energies) were reported. But these experiments were performed in a controlled environment.

TL;DR: In this paper, a simple model is outlined in order to describe the observed effect in terms of incoming flux of hydrocarbon fragments and sputter yields of the substrate and the formed disordered carbon film.

TL;DR: In this article, the electrical characteristics of sputtering induced defects were studied using DLTS measurements and a band of defect states located at 0.3 eV to 0.5 eV was found.

TL;DR: In this article, a theoretical analysis of conductances and transmission probabilities in the molecular flow regime has revealed large discrepancies with published formulae (increasing with ellipticity) and the widely used Knudsen-Dushman relation, involving the ratio of cross-sectional area to length of perimeter, was demonstrated to have no physical significance.

TL;DR: In this article, a description of an apparatus used at the National Physical Laboratory for the calibration of vacuum gauges in the range 10−4-10 Pa by the orifice flow method is given.

TL;DR: In this article, an apparatus for dynamic recoil implantation which utilizes two ion sources: a broad-beam low-energy source for the sputter deposition of the dopant material onto the substrate and a high energy source was described.

TL;DR: In this paper, a two-layer model was proposed to describe the conduction in the upper layer and allow an experimental determination of the carrier reflection coefficients at grain-boundaries and film surfaces.

TL;DR: In this article, the main sources of contamination are directly attributable to these pumps, the construction materials used in the equipment and the processing of these materials, and remedies are suggested based on practical experience gained in design and operation of vacuum systems.

TL;DR: In this paper, the effect of the interaction of active gas and ion energy on the chemical sputtering of carbon was discussed, and it was shown that the potential drop V o across an insulator resting on a biased probe is given by V o = V a + V f - V r, where V a is the applied potential between probe and anode reference electrode, and V r is the anode potential with respect to the plasma; if the anodes is abnormally small then the relation can become V oÕÕ+V f + V rÕ

TL;DR: In this article, the beam stability is closely related to the cathode condition and it is shown that the beam output is determined by secondary electron emission from the cathodes surface and this can be controlled under certain conditions, by taking appropriate measures.

TL;DR: In this article, a positive correlation was found between the occurrence of a discharge flare and breakdown of the gap, and it was suggested that breakdown was initiated by a trigger discharge at an impurity that had become charged by electron emission from its surface.

TL;DR: The Daresbury Synchrotron as discussed by the authors is a 2 GeV 1 A electron storage ring of about 30 m dia, which can accommodate up to 12 beam lines radiating tangentially from it.

TL;DR: In this paper, the authors describe a pumping group with an additional liquid nitrogen cooled baffle or plate primarily to cryopump water vapour arising from the system, and compare the performance for air and other gases when charged with polyphenyl ether fluid compared to those obtained with perfluoro polyether fluids with particular reference to their pumping stability for air, hydrogen and helium.

TL;DR: In this article, the superconducting critical temperature T c is lowered irreversibly, until an annealing temperature T t is reached at which the overlay film fractures because of the occurrence of the abnormal-to-ordinary structure transformation.

TL;DR: In this article, the lattice constant of thin heteroepitaxial layers composed of single crystal Si-Ge solid solutions various compositions grown on silicon substracts were measured by X-ray diffraction method.

TL;DR: In this article, the role of glow discharge treatment in the preparation of stainless steel surfaces has been extended to the study of electron stimulated desorption with copper surfaces in an ultra-high vacuum environment.

TL;DR: In this paper, a system for the preparation of thin films of different materials and their analysis was designed in order to enable the preparation and analysis of these materials and to enable fast transfer of prepared films and new substrates.

TL;DR: An 800 MeV synchrotron is to be built at the Rutherford Laboratory to provide intense pulsed beams of thermal neutrons as discussed by the authors, where ion pumps will be used in an ultra-high vacuum system containing no organic material.

TL;DR: In this paper, the flux of ambient particles backscattered by emissions from spacecraft surfaces is modelled for an idealized Long Duration Exposure Facility spacecraft structure in an orbit of 550 km altitude.

TL;DR: In this paper, the effects of ion bombardment on composition and surface structure of stainless steel EN58B using a dc glow discharge in Ar and a (50% Ar50% O 2 ) mixture at pressure 10 −1 torr.

TL;DR: In this paper, a numerical analysis has been performed to determine the form of evolution rate transients resulting from detrapping and diffusion of gas implanted into a solid substrate (so-called substitutional pop-out) during a linear tempering schedule of the form T = T0 + at.

TL;DR: In this article, a modified dc planar-magnetron system for cathode sputtering with an extended central magnetic pole is described, which possesses considerable advantages at least for laboratory scale dimensions (diameter less than 100 mm).

TL;DR: In this article, simple empirical expressions are given to calculate the transmission probability W (Clausing factor) of cylindrical orifices and tubes and the error is within ± 0.5% with respect to the exact values from Nawyn and Meyer 5.

TL;DR: In this article, the authors discuss the origins of back-migration of rotary pump working fluid and survey methods used to prevent and control such contamination, which can be attributed to back migration of working fluid.

TL;DR: The SRS is an electron storage ring at present under construction at the Daresbury Laboratory, Cheshire as discussed by the authors, which is an all-metal, bakeable system with a design base pressure better than 10 −10 torr.