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Extreme high vacuum chamber
Classified Abstracts 944--949 33 944. Demountable
field
emission
microscope
tube.
(Great
Britain) The design described permits rapid replacement of cathodes. Pyrex is the major construction material, the seal flange being rigidly clamped to a stainless steel stand. The system can be recycled readily after cathode installation and pumped to 1.0 -x° tort with a short bakeout, usually overnight and a brief operation of molybdenum getters. (U.S.A.) w.J.s. W. R. Savage, Vacuum, 13 (6), June 1963, 233. 33 : 16 Gas desorption efficiency under electron bombardment. See Abstr. No. 891. 33 : 1 1 : 3 1 Analysis of residual gases in T.V. picture tubes with the aid of an omegntron. See Abstr. No. 884. 33 : 18 Thermal recovery of inert gases ionicafly pumped into glass. See Abstr. No. 895. 33:22 The design and evaluation of a precision omegatron system. See Abstr. No. 915. 33 : 22 : 47 The omegatron versus a sector-type mass spectrometer for residual gas studies. See Abstr. No. 918. 33 : 30 : 41 Investigations of titanium sheets for sputtering-ion pumps. See Abstr. No. 924. 33 : 31 The analysis of residual gases in MgO cold cathode tube. See Abstr. No. 930. 33 : 31 Investigations on pressure variations of methane in an electronic valve and its influence on the emission of an oxide cathode. See Abstr. No. 932. 33 : 31 The influence of anode material on the cathode emission of low voltage valves having passive cathode cores. See Abstr. No. 934. 33 : 31 The effect of carbon in cathode metals on residual gases in electron tubes. See Abstr. No. 935. 33 : 36 : 42 Oxygen outgassing caused by electron bombardment of glass. See Abstr. No. 946. 33 : 11 : 31 Omegatron analysis of residual gases in receiving tube types. See Abstr. No. 883. Getter flashing with electrodes bombarding.
33 : 11 : 47 See Abstr. No. 882.
33 : 47 : 31 The influence of the gas ambient on the emission properties of oxide coated cathodes in receiving valves. See Abstr. No. 982. The measurement of residual gases in electron tubes. No. 970. 34.
33 : 47 : I2 See Abstr.
High Altitude and Space Technology
34 945. Extreme high vacuum chamber. (Great Britain) A brief description is given of a chamber capable of giving a vacuum of 10 -.5 torr, constructed by the N.R.C. (U.S.A.).
391
This pressure is equivalent to a gas density of 30 molecules/ cm a and was measured by a modified N.R.C.-Redhead cold cathode ion gauge, and also by a mass spectrometer. The chamber is constructed of mirror-finished stainless steel, and the extreme high vacuum chamber is surrounded by an ultra-high vacuum chamber to reduce leakage. The outer chamber measures 7 ft × 3 ft, the inner about half these dimensions. (U.S.A.) Anon., Elect. Engng., 81, Oct. 1962, 802. 36.
Drying, Degassing and Concentration
36 : 42 : 33 946. Oxygen outgassing caused by electron bombardment of glass.
(Italy) A system employing a mass spectrometer as a continuous flow gauge has been used to study the oxygen evolved from aluminum coated glass as a result of electron bombardment. The outgassing from most glasses is found to fit the empirical equation Q = Q oo ( 1 - - e x p - - t / K ) . In this equation, Q is the sum of the oxygen released during the bombardment time t and that evolved during a subsequent thermal outgas and Q oo is the maximum amount of oxygen expected from a sample bombarded for long times. Experimental results from Code 8603 glass indicate that Q oo is a measure of the range of I0 to 27 keV electrons in glass, K varies inversely with electron current per unit mass of glass affected and that electron current density may have a secondary effect on electron range in bulk glass. Oxygen outgassing data is presented from 12 commercial glasses subjected to 150/~A of 20 keV electrons bombarding a 3 × ] in. area. A mechanism of oxygen release is proposed which involves the dissipation of electron energy, the charge produced in the glass by the electrons, and the availability of non-bridging oxygen atoms in the glass structure. Data resulting from bombardment of two to four component glasses containing SiO, Na~O, K20, BaO, CaO, MgO, A120, and B2Oa are included. Results show that Na~O and K,O are the only oxides, of those studied, responsible for the oxygen release with AlcOa demonstrating a temporary effect in reducing this oxygen. (Great Britain) (Author) J. L. Lineweaver, 2nd Internat. Syrup. residual gases in electron tubes, Milan, (March 1963), Nuovo Cimento (in press). 36 947. Melted steel vacuum-degassing. (Great Britain) A review of the news reported in the literature for the last six years concerning a vacuum degassing process of melted steel is presented. After a short introductory review of gases generally present in steels and their problems, the theoretical ideas on which the process bases itself are briefly mentioned. The various methods of vacuum degassing are also described in regard to the principal construction and operation characteristics. The results and the advantages with a particular regard to the steel obtained are reported. (Italy) (Authors) C. Belvedere and A. Concina, Metallurg. ItaL, 17, (1962), 131. Volume and surface effects on metal outgnssing. No. 881. 37.
36 : 11 : 47 See Abstr.
Metallurgy, Inorganic Chemistry, Analytical Chemistry
37 948. Vacuum balance with magnetic suspension. (Great Britain) Anon., Engineer, 215 (5593), 5 April 1963, 645. 37 949. The determination of oxygen in zirconium by radio activation with 14 MeV neutrons. (Italy) The determination of oxygen in two zirconium specimens has been carried out by radioactivation with 14meV neutrons through the O x6 (n, p) N xe reaction. Fast neutrons have been
field
emission
microscope
tube.
(Great
Britain) The design described permits rapid replacement of cathodes. Pyrex is the major construction material, the seal flange being rigidly clamped to a stainless steel stand. The system can be recycled readily after cathode installation and pumped to 1.0 -x° tort with a short bakeout, usually overnight and a brief operation of molybdenum getters. (U.S.A.) w.J.s. W. R. Savage, Vacuum, 13 (6), June 1963, 233. 33 : 16 Gas desorption efficiency under electron bombardment. See Abstr. No. 891. 33 : 1 1 : 3 1 Analysis of residual gases in T.V. picture tubes with the aid of an omegntron. See Abstr. No. 884. 33 : 18 Thermal recovery of inert gases ionicafly pumped into glass. See Abstr. No. 895. 33:22 The design and evaluation of a precision omegatron system. See Abstr. No. 915. 33 : 22 : 47 The omegatron versus a sector-type mass spectrometer for residual gas studies. See Abstr. No. 918. 33 : 30 : 41 Investigations of titanium sheets for sputtering-ion pumps. See Abstr. No. 924. 33 : 31 The analysis of residual gases in MgO cold cathode tube. See Abstr. No. 930. 33 : 31 Investigations on pressure variations of methane in an electronic valve and its influence on the emission of an oxide cathode. See Abstr. No. 932. 33 : 31 The influence of anode material on the cathode emission of low voltage valves having passive cathode cores. See Abstr. No. 934. 33 : 31 The effect of carbon in cathode metals on residual gases in electron tubes. See Abstr. No. 935. 33 : 36 : 42 Oxygen outgassing caused by electron bombardment of glass. See Abstr. No. 946. 33 : 11 : 31 Omegatron analysis of residual gases in receiving tube types. See Abstr. No. 883. Getter flashing with electrodes bombarding.
33 : 11 : 47 See Abstr. No. 882.
33 : 47 : 31 The influence of the gas ambient on the emission properties of oxide coated cathodes in receiving valves. See Abstr. No. 982. The measurement of residual gases in electron tubes. No. 970. 34.
33 : 47 : I2 See Abstr.
High Altitude and Space Technology
34 945. Extreme high vacuum chamber. (Great Britain) A brief description is given of a chamber capable of giving a vacuum of 10 -.5 torr, constructed by the N.R.C. (U.S.A.).
391
This pressure is equivalent to a gas density of 30 molecules/ cm a and was measured by a modified N.R.C.-Redhead cold cathode ion gauge, and also by a mass spectrometer. The chamber is constructed of mirror-finished stainless steel, and the extreme high vacuum chamber is surrounded by an ultra-high vacuum chamber to reduce leakage. The outer chamber measures 7 ft × 3 ft, the inner about half these dimensions. (U.S.A.) Anon., Elect. Engng., 81, Oct. 1962, 802. 36.
Drying, Degassing and Concentration
36 : 42 : 33 946. Oxygen outgassing caused by electron bombardment of glass.
(Italy) A system employing a mass spectrometer as a continuous flow gauge has been used to study the oxygen evolved from aluminum coated glass as a result of electron bombardment. The outgassing from most glasses is found to fit the empirical equation Q = Q oo ( 1 - - e x p - - t / K ) . In this equation, Q is the sum of the oxygen released during the bombardment time t and that evolved during a subsequent thermal outgas and Q oo is the maximum amount of oxygen expected from a sample bombarded for long times. Experimental results from Code 8603 glass indicate that Q oo is a measure of the range of I0 to 27 keV electrons in glass, K varies inversely with electron current per unit mass of glass affected and that electron current density may have a secondary effect on electron range in bulk glass. Oxygen outgassing data is presented from 12 commercial glasses subjected to 150/~A of 20 keV electrons bombarding a 3 × ] in. area. A mechanism of oxygen release is proposed which involves the dissipation of electron energy, the charge produced in the glass by the electrons, and the availability of non-bridging oxygen atoms in the glass structure. Data resulting from bombardment of two to four component glasses containing SiO, Na~O, K20, BaO, CaO, MgO, A120, and B2Oa are included. Results show that Na~O and K,O are the only oxides, of those studied, responsible for the oxygen release with AlcOa demonstrating a temporary effect in reducing this oxygen. (Great Britain) (Author) J. L. Lineweaver, 2nd Internat. Syrup. residual gases in electron tubes, Milan, (March 1963), Nuovo Cimento (in press). 36 947. Melted steel vacuum-degassing. (Great Britain) A review of the news reported in the literature for the last six years concerning a vacuum degassing process of melted steel is presented. After a short introductory review of gases generally present in steels and their problems, the theoretical ideas on which the process bases itself are briefly mentioned. The various methods of vacuum degassing are also described in regard to the principal construction and operation characteristics. The results and the advantages with a particular regard to the steel obtained are reported. (Italy) (Authors) C. Belvedere and A. Concina, Metallurg. ItaL, 17, (1962), 131. Volume and surface effects on metal outgnssing. No. 881. 37.
36 : 11 : 47 See Abstr.
Metallurgy, Inorganic Chemistry, Analytical Chemistry
37 948. Vacuum balance with magnetic suspension. (Great Britain) Anon., Engineer, 215 (5593), 5 April 1963, 645. 37 949. The determination of oxygen in zirconium by radio activation with 14 MeV neutrons. (Italy) The determination of oxygen in two zirconium specimens has been carried out by radioactivation with 14meV neutrons through the O x6 (n, p) N xe reaction. Fast neutrons have been