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Showing papers in "Vacuum in 1971"


Journal ArticleDOI
01 Oct 1971-Vacuum
TL;DR: Experiments show that an all fluorocarbon system is possible with both diffusion and rotary pumps charged with the fluid, such an arrangement would be of value for electron beam systems if fluorOCarbon radicals could be tolerated.

28 citations


Journal ArticleDOI
01 Jan 1971-Vacuum
TL;DR: In this paper, a review is made of current studies in the writer's laboratory of rotary mechanical and oil diffusion pumps using an hf crystal microbalance and magnetic sector mass spectrometer adapted for determining the rate and composition of backstreaming products.

24 citations


Journal ArticleDOI
01 Jan 1971-Vacuum
TL;DR: In this paper, the performance and limitations of the capacitance manometer and the quartz high precision pressure gauge are discussed, and a deadweight primary pressure standard for checking the absolute accuracy of the instruments is also described.

24 citations


Journal ArticleDOI
01 Sep 1971-Vacuum
TL;DR: In this paper, the influence of the underlying metal on adsorption has been studied using Ni/Cu alloy single crystals, and the results are discussed in terms of the d-band model and Grimley's MO-theory of adorption.

11 citations


Journal ArticleDOI
01 May 1971-Vacuum
TL;DR: The fine features of silicon and oxygen K X-ray emission spectra may be used to characterize thin film and bulk "SiO" as discussed by the authors, and the Si Kα satellites Kα3 and Kα4, Si Kβ and Kβ′, and the OK band are all very sensitive to chemical combination.

10 citations


Journal ArticleDOI
01 Jul 1971-Vacuum
TL;DR: In this article, the distribution of the molecular incidence rate over the shroud of the DFVLR space simulation chamber has been calculated and reported in previous articles, and the results are shown as polar diagrams with the capture probability of the shroud as parameter.

7 citations


Journal ArticleDOI
01 Sep 1971-Vacuum
TL;DR: The quadrupole mass spectrometer has gained in recent years much popularity due to favorable characteristics, such as high sensitivity, fast mass scan, small size and especially ease of operation.

7 citations


Journal ArticleDOI
01 Mar 1971-Vacuum
TL;DR: In this paper, a simple magnetic analyzer mass spectrometer with a sensitivity of 10 −2 |torr at a resolving power of 20 was described, and the use of a miniature Wien velocity filter preceding the magnetic analyzers allowed a sensitivity 5 × 10 −3 | torr to be achieved at a resolution power of 40.

7 citations


Journal ArticleDOI
01 Dec 1971-Vacuum
TL;DR: An all steel sputtering system has been built to operate at argon pressures as low as 2 × 10−4 torr as mentioned in this paper, where background gas pressures are held below 4 × 10 −8 torr using a liquid nitrogen cooled sublimation pump during all experiments.

7 citations


Journal ArticleDOI
G.J. Rushton1, RK Fitch1
01 Oct 1971-Vacuum
TL;DR: In this article, the performance of the twin wire electrostatic charged particle oscillator is analyzed and its performance is shown to be affected by such parameters as the anode diameter, anode separation and the presence of stray magnetic fields.

6 citations


Journal ArticleDOI
01 Jan 1971-Vacuum
TL;DR: Vacuum metallurgical techniques have been used to expand the traditional areas of research and processing as discussed by the authors, and a brief history of their development can be found in the introduction.

Journal ArticleDOI
01 Oct 1971-Vacuum
TL;DR: Freeze-etching is a method which allows the internal structure of biological specimens to be studied by electron microscopy after minimal chemical pre-treatment; thus the problem of artifacts is, to some extent, reduced.

Journal ArticleDOI
RK Fitch1, G.J. Rushton1
01 Oct 1971-Vacuum
TL;DR: The electron-orbit ion gauge is a radial field thermionic ionization gauge with a sensitivity greater than 105 torr−1 as mentioned in this paper, and it is shown that below a pressure of about 10−7 torr it is necessary to operate at an emission of 10− 7 amp in order to reduce the effects of electron space charge.

Journal ArticleDOI
01 Nov 1971-Vacuum
TL;DR: To improve the performance of a vacuum pump, means are required to increase the pumping speed and to reduce the final pressure the pump can attain this article, which is required to improve the efficiency of the pump.

Journal ArticleDOI
E Fromm1
01 Dec 1971-Vacuum
TL;DR: In this article, the maximum rate attainable in sorption and degassing reactions of metals in vacuum chambers is determined by the transport in the gas phase, and the consequences resulting from this fact are discussed.

Journal ArticleDOI
01 Jul 1971-Vacuum
TL;DR: In this article, a simple theory has been formulated to account for the experimental results, which show good agreement with vapour pressure measurements by Lee 2, and indicate binding energies higher than the thick layer sublimation energy for coverages ≤ 10 16 mole/cm 2.

Journal ArticleDOI
01 Aug 1971-Vacuum
TL;DR: In this article, the behavior of metallic O-rings used under static loads for vacuum sealing is discussed, and formulae for the leak rate vs the applied loads are derived.

Journal ArticleDOI
01 Oct 1971-Vacuum
TL;DR: In this article, a time of flight mass spectrometer suitable for residual gas analysis in UHV systems is described, where the main disadvantage is the great length of the flight path, but this has been reduced to 100 mm in this instrument.


Journal ArticleDOI
01 Dec 1971-Vacuum
TL;DR: In this article, the authors investigated the pumping speeds of a set of cryosorption pumps of usual size at 77° K in the pressure range from 10−6 to 10−3 torr and were found to be about 10 /sec−1 for air.

Journal ArticleDOI
01 May 1971-Vacuum
TL;DR: In this article, the design and performance characteristics of two types of refrigerated molecular sieve sorption pumps are described and compared. But the main feature of this method of pumping is its freedom from pumping fluids.

Journal ArticleDOI
01 Sep 1971-Vacuum
TL;DR: In this article, the improvement in heat transfer properties obtained by use of Multi-Layer Insulation (MLI) is reviewed, and the importance of cleanliness during installation of MLI, of the use of heating and getter materials is demonstrated.

Journal ArticleDOI
01 Jun 1971-Vacuum
TL;DR: In this article, it is shown that a significant saving in pump-down time of large vacuum systems can be obtained with Roots pumps which are normally employed for their high pumping speed in the medium vacuum region, by driving the Roots pumps with hydrokinetic couplings which permit operation of the pumps throughout the vacuum range from atmosphere.

Journal ArticleDOI
01 Mar 1971-Vacuum

Journal ArticleDOI
01 Jun 1971-Vacuum
TL;DR: In this article, it was shown that preferential reduction in gas atom densities from different trapping centres below the target surface may be effected by bombardment with a suitable secondary ion type and energy.

Journal ArticleDOI
01 Sep 1971-Vacuum
TL;DR: In this paper, the mathematical aspect of the measure of the outgassing rate by means of the variable conductance method is investigated and the designed and built equipment is described and the results of the calculations and measurements are discussed.

Journal ArticleDOI
01 Jan 1971-Vacuum
TL;DR: In this paper, a technique for gas analysis using an MS10 has been developed whereby a continuous flow sampling calibration is set up, which avoids the need for the sophisticated equipment and time consumption of absolute pressure calibration, and provides analyses which are adequate for many applications.

Journal ArticleDOI
Hjr Perdijk1
01 Jun 1971-Vacuum
TL;DR: In this paper, the authors derived two principal equations which in the average may apply for four chemically active gases in well-functioning radio valves, which are obtained by making use of a chemical model, where a barium oxide cathode and a deposit of evaporation products on the anode are present together with low pressures of hydrogen, carbon monoxide, water vapour and carbon dioxide.

Journal ArticleDOI
A Gedanken1, B Raz1
01 Sep 1971-Vacuum
TL;DR: In this article, the authors observed continuous emission in mixtures of low concentrations (1 torr) of Xe in Argon and showed that the emission spectrum of this mixture has almost the same features as the pure Xe molecular emission spectrum, with the following differences: 1 (a) The peak's maximum is shifted 20 A towards low energy 2 (b) The amount of XE required is 025 torr while the commercially available lamps operate on 200 torr Xe 3 (c) Intensification of the emitted light was obtained by diluting the XE in

Journal ArticleDOI
01 Nov 1971-Vacuum
TL;DR: In this article, a method is proposed which permits the range of leak measurements to be extended by a factor of 10 −5 over the actual limit of mass spectrometer leak measurements.