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720. Metastable transitions observed in a time-of-flight mass spectrometer
Classified
abstracts
712-723
31. EVACUATION AND SEALING 31 : 18 Gas discharge oscillator for intense oscillations at high and superhigh frequencies. See abstract number 646. 31 :23 Improved tee connections for vacuum-jacketed transfer lines. See abstract number 681. 31 127 Method of leak detection. See abstract number 695. 31 :37 712. High pressure consolidation of vacuum encapsulated tungsten compacts. (USA) The experimental details of the pressure and temperature calibration procedures and the apparatus employed are described. It was found that dispersion strengthening cannot be effected unless the dispersoid is present in submicron sizes. E V Clougherty and J Elling, Rep UCRL-13298, May 1967, 14 pages (Sci Tech Aerospace
Reps, 5 (22), 4079, N67-37897).
31 713. Study of methods to improve high power klystron life and reliability.
(USA) Studies have been conducted on cathodes and windows for high power klystrons. Cathodes were tested in a vacuum bell jar where their operation could be observed. After 1000 cycles of 30 minutes on and 30 minutes off there were no heater failures; however some mechanical changes were observed. J Brookshier, Rep ECOM-0228-l; AD-654779, May 1967, 37 pages (Sci Tech Aerospace Reps, 5 (21), 3814, N67-35556). 31 :34 714. Cryogenic research at the Los Alamos scientific laboratory. (USA) Facilities used in cryogenic research at the Los Alamos Scientific Laboratory for the development of high thrust nuclear propulsion systems for space exploration are discussed. The largest cryogenic test cell is described and cryogenic engineering items such as storage Dewars, vacuum jacketed transfer lines, and flow control systems are discussed. E F Hammel, Rep LA-DC-8725, 1967, 31 puges (Sci Tech Aerospace Reps, 5 (21), 3826, N67-35905). 31 :46 715. Evaluation tests of a low-sinter-temperature ceramic metallizing
process. (USA) A series of evaluation tests were made of a low-sinter-temperature, refractory-metal-oxide (MoO,/MnO,) ceramic metallizing suspension. The tests were made to determine what limitations, if any, exist for the application of the low-sinter-temperature (900 to 1100°C) metallizing suspension for electron tube fabrication. The metallizing suspension was found to be easy to handle, especially since ordinary brazing furnaces can be used. No overplating was needed to produce high-strength hermetic seals. The higher tensile strength were obtained when the maximum sinter temperature of 1100°C was used in conjunction with OFHC copper, Ni-Au eutectic and Au-Cu eutectic. S R Du Buske, Rep ECOM-2851, A D-656460, May 1967, 20 pages (Sci Tech Aerospace
Reps, 5 (22), 4014, N67-37473).
31 716. Contrast fluctuations induced by ionic feedback in image con-
verter tubes. (Poland) Molecules desorbed under electron bombardment from the screen and anode of a diode image converter tube, and positively ionized, are focused at the cathode. The secondary electron emission excited by these ions lowers the resolving power of the converter. A Fryszman and B Paszkowski, Bull Acad Polon Sci St+ Sci Tech, 15 (9), 1967, 817-821 (in English). 31 :45 717. Solder for electronic vacuum apparatus. (USSR) An improved form of solder for producing vacuum-tight joints in electronic vacuum apparatus is described. The solder comprises copper 80-90, germanium 8-12, and palladium 2-12 per cent. The effective melting range of the solder is 930-990°C; it spreads easily over copper, iron, and Kovar in a hydrogen atmosphere, and on effecting a joint between copper and Kovar has an ultimate tensile stress of 42 kg/mm’. The same solder may be used for joining metallized ceramics to copper, giving a vacuum-tight joint of high mechani-
cal strength. B E Kovalevskii, USSR Patent 31st Ott 1966.
186,836,
Appl
17th Nov 1965, Pub1
31 718. Method of treating (oxidizing) components of electronic vacuum apparatus. (USSR) The general principles of the accepted method of oxidizing components (eg electrical leads) of electronic vacuum apparatus by heating in an oxidizing atmosphere are described. An improved technique is proposed in which the oxidizing atmosphere is produced and oxidizing of the components is carried out in the same vessel by the decomposition of solid ammonium carbonate. This simplifies the technological process and improves its economy. The components are placed in a dry vessel together with the ammonium carbonate but not touching the latter. The vessel is heated in a furnace to 1000°C for 10 minutes and then withdrawn into the cold zone, where the oxidized components are allowed to cool to normal temperature. D 0 Veiber and E M Kobylkin, USSR Patent 190,497, Appll6th Sept 1965, Pub1 31sr Jan 1967. 32. NUCLEONICS 719. Some recent developments in vacuum techniques for acceleratog and storage rings. (USA) A review of ultrahigh vacuum problems peculiar to accelerators and storage rings is presented. Topics discussed are vacuum pumps, beam interaction with gases, pumpdown results, repairing of leaks during pump tests, recovery from accidents and malfunctions, weld and cut joints, and alumina beam tubes. N Milleron, Rep UCRL-17296, March 1967, 23 pages (Sci Tech Aerospace
Reps, 5 (21), 3829, N67-36617).
33. GENERAL PHYSICS AND ELECTRONICS 33 : 30 Experiments with liquid and solid caesium on a rhenium substrate. See abstract number 703. 33 720. Metastable transitions observed in a time-of-flight mass spectrometer. (USA) A time-of-flight mass spectrometer has been employed in the investigation of metastable transitions by using a retarding potential technique. Expressions have been developed which permit a simple, nearly quantitative determination of the masses of the daughter ions arising from the transitions. In addition, equations are derived which permit the identification of charge exchange reactions An+t-B+AD++B(*D’-‘-. The approach has the unique feature of permitting the observation of new metastable transitions not observed in magnetic instruments. D L Dugger and R W Kiser, J Chem Phys, 47 (12), I5 Dee 1967, 5054-5061. 33 : 63 721. Bubble chambers bibliography; Supplement I. (USA) A number of 188 references are presented on bubble chambers components and applications. The references are arranged in chronological order and an author index is included. M Cornstock, Rep BNL-8083, Sup1 I, May 1967, 33 pages (Sci Tech Aerospace Reps, 5 (21), 3951, N67-35839). 33
(USSR) The ion beam gun described produces positive hydrogen or deuterium ion beams of 80 A intensity, density 3 A/cm”, and 100 keV energy, in pulses of about 1O-Bsec. The gun is based on the extraction of ions from a plasmoid produced by a spark source. S G Alikhanov et al, Pribory Tekh Ekspor, 12 (6). Nov-Dee 1967, 20-22 (in Rassian).
722. Obtaining short pulses of intense ion beams.
33 723. Injector for stationary ion beams of hydrogen with 0.5 A current
and 115 keV energy and for helium at 0.15 A and 75 keV. (USSR) The design of an injector for hydrogen and helium ions, using magnetic focusing, is described in detail. Ions are extracted from an arc discharge and the magnetic field distribution of the first focusing lens is designed to keep the electrons from the arc discharge oscillating in the space between discharge cathode and anode. The ion beam volt-ampere characteristics may be described by the 3/2 law. N V Pleshivtsev et al, Pribory Tekh Eksper. 12 (6). Nov-Dee 1967, 23-28 (in Russian). 3Of
abstracts
712-723
31. EVACUATION AND SEALING 31 : 18 Gas discharge oscillator for intense oscillations at high and superhigh frequencies. See abstract number 646. 31 :23 Improved tee connections for vacuum-jacketed transfer lines. See abstract number 681. 31 127 Method of leak detection. See abstract number 695. 31 :37 712. High pressure consolidation of vacuum encapsulated tungsten compacts. (USA) The experimental details of the pressure and temperature calibration procedures and the apparatus employed are described. It was found that dispersion strengthening cannot be effected unless the dispersoid is present in submicron sizes. E V Clougherty and J Elling, Rep UCRL-13298, May 1967, 14 pages (Sci Tech Aerospace
Reps, 5 (22), 4079, N67-37897).
31 713. Study of methods to improve high power klystron life and reliability.
(USA) Studies have been conducted on cathodes and windows for high power klystrons. Cathodes were tested in a vacuum bell jar where their operation could be observed. After 1000 cycles of 30 minutes on and 30 minutes off there were no heater failures; however some mechanical changes were observed. J Brookshier, Rep ECOM-0228-l; AD-654779, May 1967, 37 pages (Sci Tech Aerospace Reps, 5 (21), 3814, N67-35556). 31 :34 714. Cryogenic research at the Los Alamos scientific laboratory. (USA) Facilities used in cryogenic research at the Los Alamos Scientific Laboratory for the development of high thrust nuclear propulsion systems for space exploration are discussed. The largest cryogenic test cell is described and cryogenic engineering items such as storage Dewars, vacuum jacketed transfer lines, and flow control systems are discussed. E F Hammel, Rep LA-DC-8725, 1967, 31 puges (Sci Tech Aerospace Reps, 5 (21), 3826, N67-35905). 31 :46 715. Evaluation tests of a low-sinter-temperature ceramic metallizing
process. (USA) A series of evaluation tests were made of a low-sinter-temperature, refractory-metal-oxide (MoO,/MnO,) ceramic metallizing suspension. The tests were made to determine what limitations, if any, exist for the application of the low-sinter-temperature (900 to 1100°C) metallizing suspension for electron tube fabrication. The metallizing suspension was found to be easy to handle, especially since ordinary brazing furnaces can be used. No overplating was needed to produce high-strength hermetic seals. The higher tensile strength were obtained when the maximum sinter temperature of 1100°C was used in conjunction with OFHC copper, Ni-Au eutectic and Au-Cu eutectic. S R Du Buske, Rep ECOM-2851, A D-656460, May 1967, 20 pages (Sci Tech Aerospace
Reps, 5 (22), 4014, N67-37473).
31 716. Contrast fluctuations induced by ionic feedback in image con-
verter tubes. (Poland) Molecules desorbed under electron bombardment from the screen and anode of a diode image converter tube, and positively ionized, are focused at the cathode. The secondary electron emission excited by these ions lowers the resolving power of the converter. A Fryszman and B Paszkowski, Bull Acad Polon Sci St+ Sci Tech, 15 (9), 1967, 817-821 (in English). 31 :45 717. Solder for electronic vacuum apparatus. (USSR) An improved form of solder for producing vacuum-tight joints in electronic vacuum apparatus is described. The solder comprises copper 80-90, germanium 8-12, and palladium 2-12 per cent. The effective melting range of the solder is 930-990°C; it spreads easily over copper, iron, and Kovar in a hydrogen atmosphere, and on effecting a joint between copper and Kovar has an ultimate tensile stress of 42 kg/mm’. The same solder may be used for joining metallized ceramics to copper, giving a vacuum-tight joint of high mechani-
cal strength. B E Kovalevskii, USSR Patent 31st Ott 1966.
186,836,
Appl
17th Nov 1965, Pub1
31 718. Method of treating (oxidizing) components of electronic vacuum apparatus. (USSR) The general principles of the accepted method of oxidizing components (eg electrical leads) of electronic vacuum apparatus by heating in an oxidizing atmosphere are described. An improved technique is proposed in which the oxidizing atmosphere is produced and oxidizing of the components is carried out in the same vessel by the decomposition of solid ammonium carbonate. This simplifies the technological process and improves its economy. The components are placed in a dry vessel together with the ammonium carbonate but not touching the latter. The vessel is heated in a furnace to 1000°C for 10 minutes and then withdrawn into the cold zone, where the oxidized components are allowed to cool to normal temperature. D 0 Veiber and E M Kobylkin, USSR Patent 190,497, Appll6th Sept 1965, Pub1 31sr Jan 1967. 32. NUCLEONICS 719. Some recent developments in vacuum techniques for acceleratog and storage rings. (USA) A review of ultrahigh vacuum problems peculiar to accelerators and storage rings is presented. Topics discussed are vacuum pumps, beam interaction with gases, pumpdown results, repairing of leaks during pump tests, recovery from accidents and malfunctions, weld and cut joints, and alumina beam tubes. N Milleron, Rep UCRL-17296, March 1967, 23 pages (Sci Tech Aerospace
Reps, 5 (21), 3829, N67-36617).
33. GENERAL PHYSICS AND ELECTRONICS 33 : 30 Experiments with liquid and solid caesium on a rhenium substrate. See abstract number 703. 33 720. Metastable transitions observed in a time-of-flight mass spectrometer. (USA) A time-of-flight mass spectrometer has been employed in the investigation of metastable transitions by using a retarding potential technique. Expressions have been developed which permit a simple, nearly quantitative determination of the masses of the daughter ions arising from the transitions. In addition, equations are derived which permit the identification of charge exchange reactions An+t-B+AD++B(*D’-‘-. The approach has the unique feature of permitting the observation of new metastable transitions not observed in magnetic instruments. D L Dugger and R W Kiser, J Chem Phys, 47 (12), I5 Dee 1967, 5054-5061. 33 : 63 721. Bubble chambers bibliography; Supplement I. (USA) A number of 188 references are presented on bubble chambers components and applications. The references are arranged in chronological order and an author index is included. M Cornstock, Rep BNL-8083, Sup1 I, May 1967, 33 pages (Sci Tech Aerospace Reps, 5 (21), 3951, N67-35839). 33
(USSR) The ion beam gun described produces positive hydrogen or deuterium ion beams of 80 A intensity, density 3 A/cm”, and 100 keV energy, in pulses of about 1O-Bsec. The gun is based on the extraction of ions from a plasmoid produced by a spark source. S G Alikhanov et al, Pribory Tekh Ekspor, 12 (6). Nov-Dee 1967, 20-22 (in Rassian).
722. Obtaining short pulses of intense ion beams.
33 723. Injector for stationary ion beams of hydrogen with 0.5 A current
and 115 keV energy and for helium at 0.15 A and 75 keV. (USSR) The design of an injector for hydrogen and helium ions, using magnetic focusing, is described in detail. Ions are extracted from an arc discharge and the magnetic field distribution of the first focusing lens is designed to keep the electrons from the arc discharge oscillating in the space between discharge cathode and anode. The ion beam volt-ampere characteristics may be described by the 3/2 law. N V Pleshivtsev et al, Pribory Tekh Eksper. 12 (6). Nov-Dee 1967, 23-28 (in Russian). 3Of