Showing papers in "Vacuum in 1973"

TL;DR: In this paper, the behavior of impurity atoms and adsorbed oxygen atoms on a (001) iron face were studied by a four-grid type LEED-AES system.

TL;DR: In this paper, it is shown that for most purposes, a capillary is best operated at an input pressure giving a mean free path which is less than 10% of the tube length.

TL;DR: In this article, the surface cleaning of the CERN intersecting storage rings, in which the pressure is below 10 −10 torr over a 2 km length of mostly elliptical pipe (160 X 52 mm), ion bombardment during a glow discharge has been utilized.

TL;DR: In this paper, a simple glow discharge ion source is described which has been designed to etch specimens by selective sputtering Output ion currents of up to 07 mA for argon and 2 mA of hydrogen have been achieved at 8 kV.

TL;DR: In this article, the boundary conditions are formulated from the analysis of the gas balance equations on a metal surface and in a gas volume, which is taken as a foundation of the theory of gas-metal interaction in high vacuum.

TL;DR: In this article, the VCM test is used for screening and selection of materials without seriously limiting the scope of instrument designers, and the internal pressures within compartments of an instrument may be higher, depending on venting ports and the outgassing rates of materials.

TL;DR: In this paper, an internal calibration method for Auger spectra of binary alloys is proposed, which comprises the in situ breaking of pre-notched, homogenized, alloys rods in ultrahigh vacuum and the immediate analysis of the fracture surface.

TL;DR: In this paper, it is shown that the theory of the Penning discharge essentially involves taking into account the collective interaction of the electrons in the near-anode region, and empirical formulae are proposed for calculating the pumping speed and the minimum operating pressures of getter-ion pumps.

TL;DR: In this article, Monte Carlo calculations were performed for the transmission probability of cylindrical neutron guides and for the angular distribution of neutrons leaving the guide, the directions of motion of entering neutrons being assumed to obey the cosine law.

TL;DR: In this paper, preliminary electron microscopic and diffraction studies of ion implanted and recoil atom implanted thin films are described, and it is shown that the recoil implanted material forms discrete clusters within the substrate and that argon entering the silicon oxide forms bubbles.

TL;DR: In this article, the present status of AES, XPS (ESCA), APS, UPS, field emission energy analysis, LEED and RHEED is briefly surveyed, and three topics are examined in more detail: (1) electron and photon induced core level ionization, and subsequent Auger processes, measurement of electron energy distributions using retarding and bandpass analysers (CMA and hemispherical) and quantitative interpretation of Auger and photoelectron line intensities.

TL;DR: In this paper, an apparatus for ion bombardment in the energy range of 5 − 20 keV is described, where the ion beam, produced by a duoplasmatron ion source, is purified by a magnetic sector field and directed into a target chamber 60 cm in diameter.

TL;DR: In this article, a getter is mounted with an integral filamentary heater which allows activation of the porous mass, and a brief comparison with existing getters is made to indicate the fields of application of the new device.

TL;DR: In this article, various methods have been proposed for extending thermal conductivity gauges beyond their normal sensitive range in the direction of atmospheric pressure, in which both forced and natural convection have been used to extend the pressure sensitive range into the region of small Knudsen numbers.

TL;DR: In this paper, a simple extension of the long tube formula is given whereby the pressure profile may be determined along a uniformly outgassing pipe pumped at both ends of the pipe.

TL;DR: The physical background to the metallurgy of ion implantation is discussed in this article, where the fate of implanted atoms is considered in the content of the precipitation processes which occur as a consequence of exceeding the solubility limit during implantation.

TL;DR: In this article, a design for the accurate alignment of high voltage plane parallel electrodes used in an ultra-high vacuum assembly is described, which is shown to be relatively simple to fabricate.

TL;DR: In this paper, the rate of oxygen by zirconium at very low pressures of 4 ×10 −6 to 4×10 −4 torr has been investigated in the temperature range 500 −850°C using a microbalance.

TL;DR: The theory of viscosity gauges of the moving ribbon or fibre type for operation at low pressure (in the region of large mean free paths) is reviewed in this paper.

TL;DR: In this paper, preliminary surface studies using work function techniques are reported for the (110) face of the refractory metals tantalum, niobium, molybdenum and tungsten, both in the clean state and during the introduction of pure oxygen gas at room temperature.

TL;DR: In this article, a simple vacuum bubble device for visualizing gas flows is described and the parameters controlling its sensitivity are examined from a physical viewpoint, and expressed in algebraic form for experimental testing.

TL;DR: In this article, the authors used a residual gas analyzer to lower the limit of detection of oxygen by mass spectrometric analysis to about 700 pPa.l (5 × 10−12 torr.l).

TL;DR: In this article, the authors extend these recipes to a general criterion for high vacuum sealing: a contact pressure at the rubber-metal interface of 13 kg/cm2, which is the minimum required compression force and the maximum allowed gap (if required) between mating flanges.

TL;DR: In this paper, the twin anode electrostatic ion source has been modified to produce two separate ion beams of equal intensity, which can be used to ion etch two specimens at the same time under identical conditions of beam density, ion energy and pressure.

TL;DR: The accuracy and repeatability of pressure measurement of the Moser and Poltz McLeod gauge have been studied in this article, where it is estimated that the accuracy and sensitivity of the conventional optical method used for measurement is insufficient.

TL;DR: In this article, the experimental difficulties of heating a relatively large area of a highly reactive material like silicon in ultra high vacuum to temperatures near its melting point have been considered and various methods of heating are investigated and a design with multiple substrate heating facility is described.