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58. Magnetic electrical discharge pumps with cold cathodes. (Review)
Classified abstracts 46-60 pumps is presented in tabular form. The authors suggest that cryopumps are particularly advantageous when pressures below 10 -3 tort must be maintained. (France) J Ronssel et al, Le Vide, 20 (118), July-August 1965, 249-280. 21 46. Experimenting with a travelling-wave pump. (France) Travelling magnetic fields can be used for accelerating conductive fluids. In this manner the electrodes can be eliminated as well as the phenomenon of polarization and corrosion. Devices based on this principle also provide analog set-ups for travelling-wave plasma accelerators, and their design allows a better understanding of the working conditions of these accelerators. The experimental study of a Hg pump shows the good agreement between theoretical predictions and the experimental results. (France) J Paulon, Recherches A&ospatiale, 106, May-June 1965, 11-20,
(in French). 21 47. Orbitron pump. (USA) The performance of " o r b i t r o n " ion-sublimation vacuum pumps for pumping plasma vacuum chambers is tested. I Henins et al, Los Alamos Scientific Lab, Univ of California, New
Mexico, 1965. 21 48. Vacuum pumps. (USA) This article describes different types of pumps that have been developed, and the degree of vacuum that can be obtained by their use. F Marton, Instrums Control Syst, 38 (9), Sept 1965, 106-112. 21 49. Design and overall performance of an axial-flow pump rotor with a blade-tip diffusion factor of 0.66. (USA) M J Miller and J E Crouse, NASA, TN/D3024, Sept 1965, 1-27. 21 50. Liquid helium GSE for centaur turbopump chilldown. (USA) J J Gilbean et al, AIAA, July 1965, 65-523. 21 51. Cryogenic vacuum pumps. (USA) A new family of cryogenic pumps capable of evacuating huge chamber volumes to pressures in the ultra-high vacuum range is described. G F Hagenbach, Industrial Research, Sept 1965, 67-75. 21 52. Cross-stresses in the flow of different pumps. (Netherlands) Investigation by means of a centripetal vacuum pump of the crossstresses effect discovered by Reiner in the lamina flow of air for the case of different gases. It was found that monatomic gases as well as diatomic and triatomic gases show the same effect with the same order of magnitude, dependent on the ambient pressure and temperature only. (Israel) A Fonx and M Reiner, Topics in Applied Mechanics, Elsevier Publ,
(Amsterdam), 1965, 159-168. 21 : 37 53. Pump improves spark source technique. (USA) A cryosorption pump developed by the authors has enabled them to improve markedly the quantitative determination of parts-permillion levels of impurities in metals by spark source mass spectrometry. H Murrison, Chem Engng News, 25 Oct 1965, 36-37. 21 : 41 54. The performance of a high-speed getter pump using a cooled titanium film. (GreatBritain) A practical getter pump using evaporated titanium on a liquid nitrogen cooled surface is described. The complete vacuum system is made of stainless steel using gold wire gaskets and is bakeable to 400°C. An ultimate pressure of 2 × 10 -x° tort is regularly obtained when used in conjunction with a sputter ion pump. The principal feature of the pump is the use of 85 per cent Ti, 15 per cent Mo alloy as the evaporating filament. Details of the performance of this type o f filament are given. Measurements of the pumping speed for hydrogen were made using a surface area of 3650 cm 2 with an average titanium coverage of 5/~gm/cm 2. Initial speeds of up to 50,000 l./sec were obtained and ,~1 torr-litre of hydrogen was sorbed by the time the speed had fallen to 15,000 1./sec. The initial pumping speeds are higher than the conductance limit of the pump. The curves of pumping speed vs time, moreover, show no sign of being conductance limited. This and other evidence indicates that adsorption-desorption processes are taking place on the liquid-
46
nitrogen cooled stainless steel, apart from the pumping action of the titanium film. (Great Britain) (Author) G M MeCracken, Vacuum, 15 (9), Sept 1965, 433-436. 21 55. Zeolite vacuum units for continuously operated oil-free evacuation.
( USSR) Descriptions are given of various zeolite sorption units, suitable for continuous operation, which are capable of maintaining pressures of 10 -3 to 10 -4 torr in volumes of 10 to 100 litres. Two types are designed for evacuation from atmospheric pressure down to 10 -2 tort; two other designs enable lower pressures of 10 -4 torr to be reached after a preliminary evacuation with a water-jet pump. Prior to use, the zeolite is activated by heating for 20 hours at a temperature of about 500°C. The results of experiments show that a named grade of zeolite is satisfactor~ for the absorption of Xe, Kr, At, N2 and 02, but the absorption of hydrogen is weak, and absorption of He and Ne is very slight. It is noted that air is absorbed better by certain grades of zeolite than by either silica-gel or activated charcoal. Some technical characteristics of zeolite units are presented together with diagrams and descriptions of experimental work. An application of a zeolite pump for evacuating the jacket of a Dewar flask is discussed. (USSR) E N Martinson et al, Pribory i Tekh Eksper, 4, 1965,154, (in Russian). 21 : 33 : 34 56. Several considerations for environmental testing under simulated space environments. (USA) Discussion of thermal-vacuum facilities and methods for testing in simulated space environments. Considerations for achieving high vacuum are discussed and the cryopumping mechanism is reviewed. H W Lekuch, Symposium on Manned Space Reliability, Anaheim,
California 1964, Western Periodicals Co, 1964, 49-79. 21 : 34 57. Design of a large ion-getter pumped space simulation facility.
(USA) Description of an ion-getter pumped facility which has two large chambers with an ultimate pressure in the 10-11 tort range. M Barron, Proc Inst Environmental Sciences, 1965, 257-261. 21 58. Magnetic electrical discharge pumps with cold cathodes. (Review). ( USSR) The authors consider the evacuation mechanism, characteristics, design (with particular reference to Russian pumps), operation and application of this type of pump. A summary lists nine advantages and five disadvantages. ( a r t T) Yu A Kurpnv et al, Instrum & Exper Tech, Nov 1964, 269-279. Translated from Pribory i Tekh Eksper, 2, March-April 1964. 21 59. Hydrogen pressure fluctuations in vacuum bodies evacuated by oilvapour pumps. (USSR) In the metal chamber of a pulse mass spectrometer evacuated by an oil diffusion pump, the residual gas (total pressure 5 × 10 -9 torr) was found to be mainly hydrogen with small amounts of H=O, CO and COs. The pressure of H2 (but not of the other gases) fluctuated by 20-30 per cent about a mean value, the frequency of fluctuation being about 1 cps. Increasing the voltage on the pump heater from 127 to 140 volts reduced the amplitude of these fluctuations by almost one order of magnitude without affecting the ultimate pressure or the pump speed. (A H T) V N Ageev and Yu K Ustinov, lnstrum & Exper Tech, August 1965, 225. Translated from Pribory i Tekh Eksper , 1, Jan-Feb 1965. 21 60. The effective evacuation rate of an electrical-discharge pump.
(USSR) The effect on pumping speed of the cell arrangement in an electricaldischarge (Penning) pump is considered. (A H T) G A Vasil'ev, Instrum & Exper Tech, August 1965, 146-148. Translated from Pribory i Tekh Eksper, 1, Jan-Feb 1965.
22. Gauges 22:14 Kinetic theory of the mercury drag effect in vacuum measurements with a McLeod gauge. See abstract number 17. 22:16 Mass spectrometer method for investigating the hydrogen permeability of thermally stable materials. See abstract number 23.
(in French). 21 47. Orbitron pump. (USA) The performance of " o r b i t r o n " ion-sublimation vacuum pumps for pumping plasma vacuum chambers is tested. I Henins et al, Los Alamos Scientific Lab, Univ of California, New
Mexico, 1965. 21 48. Vacuum pumps. (USA) This article describes different types of pumps that have been developed, and the degree of vacuum that can be obtained by their use. F Marton, Instrums Control Syst, 38 (9), Sept 1965, 106-112. 21 49. Design and overall performance of an axial-flow pump rotor with a blade-tip diffusion factor of 0.66. (USA) M J Miller and J E Crouse, NASA, TN/D3024, Sept 1965, 1-27. 21 50. Liquid helium GSE for centaur turbopump chilldown. (USA) J J Gilbean et al, AIAA, July 1965, 65-523. 21 51. Cryogenic vacuum pumps. (USA) A new family of cryogenic pumps capable of evacuating huge chamber volumes to pressures in the ultra-high vacuum range is described. G F Hagenbach, Industrial Research, Sept 1965, 67-75. 21 52. Cross-stresses in the flow of different pumps. (Netherlands) Investigation by means of a centripetal vacuum pump of the crossstresses effect discovered by Reiner in the lamina flow of air for the case of different gases. It was found that monatomic gases as well as diatomic and triatomic gases show the same effect with the same order of magnitude, dependent on the ambient pressure and temperature only. (Israel) A Fonx and M Reiner, Topics in Applied Mechanics, Elsevier Publ,
(Amsterdam), 1965, 159-168. 21 : 37 53. Pump improves spark source technique. (USA) A cryosorption pump developed by the authors has enabled them to improve markedly the quantitative determination of parts-permillion levels of impurities in metals by spark source mass spectrometry. H Murrison, Chem Engng News, 25 Oct 1965, 36-37. 21 : 41 54. The performance of a high-speed getter pump using a cooled titanium film. (GreatBritain) A practical getter pump using evaporated titanium on a liquid nitrogen cooled surface is described. The complete vacuum system is made of stainless steel using gold wire gaskets and is bakeable to 400°C. An ultimate pressure of 2 × 10 -x° tort is regularly obtained when used in conjunction with a sputter ion pump. The principal feature of the pump is the use of 85 per cent Ti, 15 per cent Mo alloy as the evaporating filament. Details of the performance of this type o f filament are given. Measurements of the pumping speed for hydrogen were made using a surface area of 3650 cm 2 with an average titanium coverage of 5/~gm/cm 2. Initial speeds of up to 50,000 l./sec were obtained and ,~1 torr-litre of hydrogen was sorbed by the time the speed had fallen to 15,000 1./sec. The initial pumping speeds are higher than the conductance limit of the pump. The curves of pumping speed vs time, moreover, show no sign of being conductance limited. This and other evidence indicates that adsorption-desorption processes are taking place on the liquid-
46
nitrogen cooled stainless steel, apart from the pumping action of the titanium film. (Great Britain) (Author) G M MeCracken, Vacuum, 15 (9), Sept 1965, 433-436. 21 55. Zeolite vacuum units for continuously operated oil-free evacuation.
( USSR) Descriptions are given of various zeolite sorption units, suitable for continuous operation, which are capable of maintaining pressures of 10 -3 to 10 -4 torr in volumes of 10 to 100 litres. Two types are designed for evacuation from atmospheric pressure down to 10 -2 tort; two other designs enable lower pressures of 10 -4 torr to be reached after a preliminary evacuation with a water-jet pump. Prior to use, the zeolite is activated by heating for 20 hours at a temperature of about 500°C. The results of experiments show that a named grade of zeolite is satisfactor~ for the absorption of Xe, Kr, At, N2 and 02, but the absorption of hydrogen is weak, and absorption of He and Ne is very slight. It is noted that air is absorbed better by certain grades of zeolite than by either silica-gel or activated charcoal. Some technical characteristics of zeolite units are presented together with diagrams and descriptions of experimental work. An application of a zeolite pump for evacuating the jacket of a Dewar flask is discussed. (USSR) E N Martinson et al, Pribory i Tekh Eksper, 4, 1965,154, (in Russian). 21 : 33 : 34 56. Several considerations for environmental testing under simulated space environments. (USA) Discussion of thermal-vacuum facilities and methods for testing in simulated space environments. Considerations for achieving high vacuum are discussed and the cryopumping mechanism is reviewed. H W Lekuch, Symposium on Manned Space Reliability, Anaheim,
California 1964, Western Periodicals Co, 1964, 49-79. 21 : 34 57. Design of a large ion-getter pumped space simulation facility.
(USA) Description of an ion-getter pumped facility which has two large chambers with an ultimate pressure in the 10-11 tort range. M Barron, Proc Inst Environmental Sciences, 1965, 257-261. 21 58. Magnetic electrical discharge pumps with cold cathodes. (Review). ( USSR) The authors consider the evacuation mechanism, characteristics, design (with particular reference to Russian pumps), operation and application of this type of pump. A summary lists nine advantages and five disadvantages. ( a r t T) Yu A Kurpnv et al, Instrum & Exper Tech, Nov 1964, 269-279. Translated from Pribory i Tekh Eksper, 2, March-April 1964. 21 59. Hydrogen pressure fluctuations in vacuum bodies evacuated by oilvapour pumps. (USSR) In the metal chamber of a pulse mass spectrometer evacuated by an oil diffusion pump, the residual gas (total pressure 5 × 10 -9 torr) was found to be mainly hydrogen with small amounts of H=O, CO and COs. The pressure of H2 (but not of the other gases) fluctuated by 20-30 per cent about a mean value, the frequency of fluctuation being about 1 cps. Increasing the voltage on the pump heater from 127 to 140 volts reduced the amplitude of these fluctuations by almost one order of magnitude without affecting the ultimate pressure or the pump speed. (A H T) V N Ageev and Yu K Ustinov, lnstrum & Exper Tech, August 1965, 225. Translated from Pribory i Tekh Eksper , 1, Jan-Feb 1965. 21 60. The effective evacuation rate of an electrical-discharge pump.
(USSR) The effect on pumping speed of the cell arrangement in an electricaldischarge (Penning) pump is considered. (A H T) G A Vasil'ev, Instrum & Exper Tech, August 1965, 146-148. Translated from Pribory i Tekh Eksper, 1, Jan-Feb 1965.
22. Gauges 22:14 Kinetic theory of the mercury drag effect in vacuum measurements with a McLeod gauge. See abstract number 17. 22:16 Mass spectrometer method for investigating the hydrogen permeability of thermally stable materials. See abstract number 23.