933. Vacuum-tight hose fastening

Classified abstracts 932-945 gas pressures. A flat member is rotatable about an axis passing through its plane. An optical system measures any rotation. A tube surrounding the member is the source of heat and a screen is placed between this heated tube and the rotatable member. As infra-red radiation may strike the member to produce any mechanical couple, the screen enables the accelerated gas molecules to strike the member and produce the mechanical couple to be measured. Labs D'Eiectronique et de Physique Appliquees L E P, Brit Patent 1.055,508, Patent ,4bstr, 7 (7) part D, 8th Feb 1967, 8. 23. P L U M B I N G 23 932. The force cycle of vacuum gasket seals. (Great Britain) A recently developed method of seal assessment has shown that an appropriate representation of the force cycle of a vacuum gasket seal gives multilateral information on the factors influencing it. The various types of force cycle are discussed and the analytical correlation between the shape of the cycle and the phenomena determining the sealing effect is demonstrated. A graphical procedure is described for plotting the releasing path of the cycle from the tightening path, and vice versa, and experimental values are compared with calculated values. Standard parameters are proposed for describing the force cycle and the most characteristic shapes are presented. Applications of the force cycle shapes in establishing the suitability of seals for special purposes (repeated opening, baking, cryogenics etc) are also discussed. A Roth and A Inbar, Vacuum, 17 (1), Jan 1967, 5-14. 23 933. Vacuum-tight hose fastening. (Germany) To secure a metal connecting piece to the end of a metal hose, a cylindrical filler piece is inserted between the roughly cylindrical sleeve of the connecting piece and the metal hose. The sleeve of the connecting piece and the filler piece are pressed onto the hose so as to fill the grooves in the hose. The filler piece is of electrically conductive material and the sleeve and filler piece are pressed onto the hose by electromagnetic effect. (Author) Metalischlauch-Fah Pforzbeim, German Patent 1,231,978, Patent Abstr, 7 (6) part A, 9th Feb 1967, 2. 25. BAFFLES, TRAPS AND REFRIGERATION E Q U I P M E N T 25 934. A liquid He cooled trap for ultrahigh vacuum systems. (Great Britain) An all-Pyrex liquid He trap has been designed and tested on a Venema and Bandringa type of ultrahigh vacuum system incorporating a mass spectrometer. An overall reduction in total pressure of about one order was achieved, the remaining gases being H~ and water vapour. B J Hopkins and K R Pender, J Sci lnstrum, 44, 1967, 73-74. 25 935. Cryogenic devices using the continuous flow principle. (Great Britain) This is an extended abstract of a previously published paper. The design and construction of a continuous flow cryostat is illustrated diagrammatically and the operating principles summarized. Applications of the device include cryopumps, cold fingers, miniature liquefiers and small experimental chambers. H J Forth, Vacuum, 17 (1), Jan 1967, 21-22. 26. AUTOMATIC PROTECTIVE AND CONTROL E Q U I P M E N T 26 936. Control of temperature and liquid height in cryostats below 4.2°K. (Germany) An automatic liquid He cryostat is described in which temperature is continuously kept constant at below 4.2°K by maintaining a constant reduced pressure with a vacuum pump, pressure regulator and regulating valve, while a fixed liquid level is continuously maintained by a liquid-level sensor and regulator which controls the introduction of liquid He from a reservoir via a cold He gas-jacketed siphon. A Eisner et al, Kaelteteehnik, 18, 1966, 233-237. 26 937. Cryogenic irradiation testing. (USA) Material specimens and electrical and mechanical components having potential space applications were exposed to various combinations of radiations, vacuum and cryogenic environments. The effects on the operating characteristics of components were determined. The facility set-up is described and illustrated. E T Smith, Cryog Eng News, 1, 1966, 20-25.

26 938. A cryopump for use in low temperature control, (Great Britain) An apparatus for obtaining controlled low temperatures using a specially designed cryopump is described. The apparatus is a closed system which reduces the hazards connected with explosion or toxic refrigerants. C C Lira et al, J Sci, Instrum, 44, 1967, 68-69. 26 939. Precision temperature control. (Great Britain) Problems associated with accurate control of temperature and the examination of the various types of temperature-sensitive elements are discussed. It is shown that the thermistor offers greatest sensitivity and stability. The criteria underlying the design of a temperaturesensitive bridge using a thermistor are analyzed. E C Bell and L N Hulley, Inst Elec Eng, 113, 1966, 1671-1677. 27. LEAK DETECTORS AND LEAK DETECTION 27 940. Methods and apparatus for leak detection and location. (Germany) A review of the methods and apparatus employed for the detection of leaks in vacuum systems is given. G Kienel, Glas-lnstrum-Tech, 10, 1966, 761-766 and 769-770 (in German). 28. HEATING E Q U I P M E N T AND T H E R M O M E T E R S 28 941. An improved electron bombardment evaporation source for powdered materials. (Great Britain) The construction of an electron bombardment evaporation source, mainly for use in the evaporation of powdered materials, is described and its advantages enumerated. As an example, results of evaporation of silicon monoxide are presented. J Pick, J Sci Instrum, 44, 1967, 70-71. 28 942. Electron beam gun. (Great Britain) The gun is intended for use in ion gauges, electrometer tubes, amplifying devices and ion-getter pumps. The anode is long and cylindrical and is surrounded by a boundary electrode with elongated cathode in the vacuum space between. The cathode is parallel to the anode and set towards one end to modify the electric field. With the aid of a magnetic field, the electrons are given sufficient angular momentum to go into spiral orbit around the anode. Wisconsin Alumini Res Foundation, Brit Patent 1,054,133, Patent Abstr, 7 (5), part D, 26th Jan 1967, 11.

III. Vacuum applications 30. EVAPORATION AND SPUTTERING 30:15 Adsorption and desorption of hydrogen by evaporated molybdenum films at low temperatures. See abstract number 891. 30 : 45 Microwelding of vacuum deposited thin films. See abstract number 1036. 3O 943. Epitaxial growth of silicon by vacuum deposition. (Japan) Single crystal silicon films were grown on ruby substratcs by vacuum evaporation. Apparatus and experimental procedure are described. Epitaxial temperature was lower than that for chemical deposition. The (11 I) silicon plane was parallel to the (0001) ruby substrate. With a substrate temperature of 900°C and an evaporation rate of 26 micrograms/see, p-type silicon films were obtained whose mobility of 200 cm2/volt-sec was almost half the value for bulk silicon. T Itoh et al, J Vac Soe Japan, 9 (12), 1966, 472-479 (in Japanese). 3O 944. Vapour growth of SiO2 and TiO= films. (Japan) The vapour phase growth of SiO~ and TiO2 films on Si substrates and the characteristics of these films are described. Apparatus, materials and deposition processes of SlOe by the SiCI4--CO~ system are shown in detail. H Teshima et al, Electrotech Lab Bull, 30, 1966, 45-48 (in Japanese). 3O 945. Stress in vacuum deposited films of silver. (Japan) Measurements have been made of the tensile stress in Ag films evaporated in a vacuum of 1-2 × 10-5 torr on to mica strips, with

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