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1481. Chamber pumping system for large-size electro-vacuum devices
Classified abstracts 1480-1492 of the X-ray diffraction method are presented. V D Grebenyuk et al, Fiz Elektron, 3, 1970, 86-88 (in Ukrainian).
II. Vacuum apparatus and auxiliaries 20. P U M P I N G SYSTEMS 20 1481). High-vacuum evaporators B30.1 and B30.2 new universal systems for research, teaching and small production. (Germany) New high-vacuum evaporators type B30.1 and B30.2 are described. Both apparatuses have vertical bell-jars with 300 mm diameter. Using additional arrangements, they can be used for performing different evaporation processes in research and small production. K Weber and N Solger, Vakuum Information, 3 Aug, 1971, 57-60 (in
German). 20 1481. Chamber pumping system for large-size electro-vacuum devices. (USSR) Construction and performance of a chamber pumping system for evacuation and hermetization of large-size electro-vacuum devices are described. K N Orlov et al, Elektron Prom, No 1, 1971, 99-102 (in Russian). 21. P U M P S AND P U M P FLUIDS 21 1482. The pumping speed of an ion-getter pump at very low temperatures. (Germany) Ultrahigh vacuum pumps for a superconducting particle accelerator have to operate at 1.8°K and be essentially effective in pumping helium. Tests were carried out on an 11 litre Ultek pump, with titanium/tantalum cathodes, mounted in a helium bath cryostat. The temperature dependence of the field strength in the gap of the ferrite magnet was determined. Results are discussed. P FiScher and R Vingon, Vakuum-Technik, 20 (5), July 1971, 135-138
(in German). 21 1483. Condensation method of forevacuum pumping lI. Forevacuum condensation pump with throughput 3 × 108 litre torr/sec. (USSR) Construction, principle of operation and results of examinations are described for a condensation pump with throughput of 3 × 108 litre torr/sec, intended for forevacuum pumping. A regulated hydraulic resistance is placed between the pumped volume and the pump. Continuous and pulsed regimes of the condensation pump are discussed. E S Borovik et al, Ukr Fiz Zh, 15 (12), 1970, 1968-1973 (in Russian). 21 1484. Experimental investigations on double nozzles in oil diffusion pumps. (Germany) Two different constructions of double nozzles with the variable clearance area are explored and compared with a simple nozzle in an oil diffusion pump. Behaviour of the pumping speed, oil vapour backstreaming and fore-pump effect are investigated. It is concluded that application of the double nozzles does not result in noticeable improvement of pump characteristics as compared to application of a simple nozzle. S Szyska, Vakuum Information, 3, 1971, 61-64 (in German). 22. GAUGES 22 1485. New ionization gauge for high pressures. (France) A triode ionization gauge with a measuring range from 1 × 10 6 to 5 × 10 1 torr is described. The shape of the gauge tube defines the electron path and the gauge will operate in oxidizing atmospheres. M Mareehal, Le Vide, 26 (152), March-April 1971, 55-57 (in French). 22 1486. Multipliers with continuous dynodes for recording of charged particles. (USSR) The basic parameters and characteristics of channel electron multipliers are presented which are used for recording of charged particles. M R Aynbund et al, Elektron Tekh Elektronluch Fotoelektr Prib, 4, 1970, 47-51 (in Russian). 22:31 1487. Vacuum measurement in sealed camera television tubes. (USSR) The residual pressure in sealed superorthicons, is measured by a controlled gas discharge in the region focusing electrode-multiplier
618
cylinder-anode immersed in a longitudinal magnetic field, or by ionization of the residual gas by an electron beam passing through electron multiplier. Circuit diagrams for both measuring methods are presented. The dependence of the discharge current on the gas pressure in a conventional sealed superorthicon is determined. The limits of the measuring method are analyzed. It is found that the method based on gas discharge changes the surface properties of first multiplier stage and causes leaks between electrodes. The method based on ionization of residual gas has a sensitivity 3 orders of magnitude lower but it can be used for reliable pressure measurement in the range 4× 10-7 to 1 × 10-5 torr in sealed superorthicons. No changes were observed in superorthicons even after 2 hours duration of measurement. An instrument for rapid measurement of residual gas pressure in superorthicons and other television camera tubes is described. A M Miukin, Elektron Tekh Elektronluch Fotoelektr Prib, 2, 1970, 80-86 (in Russian). 22 1488. The current efficiency of a radio-frequency mass spectrometer. (Czechoslovakia) The current efficiency, characterized by the ratio of the collector current to the ion current on the input of the spectrometer of a Bennett type radio-frequency mass spectrometer was measured as a function of the retarding potential. The disagreement between the experimental data and theory, observed by several authors, is discussed. This discrepancy is explained by the great spread in energy of ions at the ion source. A new experimental method has been used to study this problem and the experimental results obtained are shown to agree well with the theory. The Bennett radio-frequency mass spectrometer used in these studies is a 7--5 cycle, three-stage instrument. The measured spread in the energy of ions reached up to 27 eV. V Martisovits, Fyzik Cas, 20 (2), 1970, 110-115. 22 1489. Thermal gauge for high vacuum to 10 6 torr. (USSR) Construction of a heat-conductivity vacuum gauge is described which can be used for measurement of pressure down to high vacuum range. B P Kozyrev, IzvLeningr Elektrotekh lust, 94, 1970, 20-23 (in Russian). 22 : 30 1490. Arrangement for mass-spectroscopic composition analysis of molecular beams of condensing materials with the aid of instrument KM 1. (USSR) An arrangement for investigating the composition of molecular beams, bombarding a substrate during vacuum evaporation, is described which contains a quadrupole mass spectrometer and a vacuum evaporator. The cross beam ion source of the mass spectrometer is placed above the evaporator in the vacuum chamber. A shield, controlled electromagnetically, is placed between the evaporator and the ion source. Calibration of the mass spectrometer for determination of the evaporation rate from the signal of the quadrupole is performed with the aid of a microinterferometer. The microinterferometer is used for determination of thickness of the deposited layers. In the evaporation of complex materials, which have a greater number of isotopes, and for condensation coefficients considerably differing from unity, the relationship between the output signal of the quadrupole and the evaporation rate is complex. Mass spectra obtained for evaporation of copper from a molybdenum boat at 1.8× 10-5 torr are presented. The minimum detectable evaporation rate for copper was 4 × 10-2 A./sec. It is demonstrated that the quadrupole mass spectrometer can be used for measurement of molecular beam intensities in a broad range of 0.04 to above 100 /~/sec of copper. G I Slobodenyuk et al, Zavodsk Lab, 37 (4), 1971,492-494 (in Russian). 22 1491. Manometric glass vessel with plane diaphragm. (USSR) A manometric glass vessel separated into two parts by a plane diaphragm is described. It is suitable for pressure measurement in systems placed in a thermostat. A P Alekseev et al, Zavodsk Lab, 37 (5), 1971, 627 (in Russian). 22 1492. Simple diaphragm gauge. (USSR) Construction of a simple diaphragm vacuum gauge is described. The stationary electrode is coated by a thin polymer film, less than 1 micron thick deposited in glow discharge plasma. The circuit diagram of the gauge is presented. L S Tuzov and A B Lipatov, Zavodsk Lab, 37 (5), 1971, 625-626 (in
Russian).
II. Vacuum apparatus and auxiliaries 20. P U M P I N G SYSTEMS 20 1481). High-vacuum evaporators B30.1 and B30.2 new universal systems for research, teaching and small production. (Germany) New high-vacuum evaporators type B30.1 and B30.2 are described. Both apparatuses have vertical bell-jars with 300 mm diameter. Using additional arrangements, they can be used for performing different evaporation processes in research and small production. K Weber and N Solger, Vakuum Information, 3 Aug, 1971, 57-60 (in
German). 20 1481. Chamber pumping system for large-size electro-vacuum devices. (USSR) Construction and performance of a chamber pumping system for evacuation and hermetization of large-size electro-vacuum devices are described. K N Orlov et al, Elektron Prom, No 1, 1971, 99-102 (in Russian). 21. P U M P S AND P U M P FLUIDS 21 1482. The pumping speed of an ion-getter pump at very low temperatures. (Germany) Ultrahigh vacuum pumps for a superconducting particle accelerator have to operate at 1.8°K and be essentially effective in pumping helium. Tests were carried out on an 11 litre Ultek pump, with titanium/tantalum cathodes, mounted in a helium bath cryostat. The temperature dependence of the field strength in the gap of the ferrite magnet was determined. Results are discussed. P FiScher and R Vingon, Vakuum-Technik, 20 (5), July 1971, 135-138
(in German). 21 1483. Condensation method of forevacuum pumping lI. Forevacuum condensation pump with throughput 3 × 108 litre torr/sec. (USSR) Construction, principle of operation and results of examinations are described for a condensation pump with throughput of 3 × 108 litre torr/sec, intended for forevacuum pumping. A regulated hydraulic resistance is placed between the pumped volume and the pump. Continuous and pulsed regimes of the condensation pump are discussed. E S Borovik et al, Ukr Fiz Zh, 15 (12), 1970, 1968-1973 (in Russian). 21 1484. Experimental investigations on double nozzles in oil diffusion pumps. (Germany) Two different constructions of double nozzles with the variable clearance area are explored and compared with a simple nozzle in an oil diffusion pump. Behaviour of the pumping speed, oil vapour backstreaming and fore-pump effect are investigated. It is concluded that application of the double nozzles does not result in noticeable improvement of pump characteristics as compared to application of a simple nozzle. S Szyska, Vakuum Information, 3, 1971, 61-64 (in German). 22. GAUGES 22 1485. New ionization gauge for high pressures. (France) A triode ionization gauge with a measuring range from 1 × 10 6 to 5 × 10 1 torr is described. The shape of the gauge tube defines the electron path and the gauge will operate in oxidizing atmospheres. M Mareehal, Le Vide, 26 (152), March-April 1971, 55-57 (in French). 22 1486. Multipliers with continuous dynodes for recording of charged particles. (USSR) The basic parameters and characteristics of channel electron multipliers are presented which are used for recording of charged particles. M R Aynbund et al, Elektron Tekh Elektronluch Fotoelektr Prib, 4, 1970, 47-51 (in Russian). 22:31 1487. Vacuum measurement in sealed camera television tubes. (USSR) The residual pressure in sealed superorthicons, is measured by a controlled gas discharge in the region focusing electrode-multiplier
618
cylinder-anode immersed in a longitudinal magnetic field, or by ionization of the residual gas by an electron beam passing through electron multiplier. Circuit diagrams for both measuring methods are presented. The dependence of the discharge current on the gas pressure in a conventional sealed superorthicon is determined. The limits of the measuring method are analyzed. It is found that the method based on gas discharge changes the surface properties of first multiplier stage and causes leaks between electrodes. The method based on ionization of residual gas has a sensitivity 3 orders of magnitude lower but it can be used for reliable pressure measurement in the range 4× 10-7 to 1 × 10-5 torr in sealed superorthicons. No changes were observed in superorthicons even after 2 hours duration of measurement. An instrument for rapid measurement of residual gas pressure in superorthicons and other television camera tubes is described. A M Miukin, Elektron Tekh Elektronluch Fotoelektr Prib, 2, 1970, 80-86 (in Russian). 22 1488. The current efficiency of a radio-frequency mass spectrometer. (Czechoslovakia) The current efficiency, characterized by the ratio of the collector current to the ion current on the input of the spectrometer of a Bennett type radio-frequency mass spectrometer was measured as a function of the retarding potential. The disagreement between the experimental data and theory, observed by several authors, is discussed. This discrepancy is explained by the great spread in energy of ions at the ion source. A new experimental method has been used to study this problem and the experimental results obtained are shown to agree well with the theory. The Bennett radio-frequency mass spectrometer used in these studies is a 7--5 cycle, three-stage instrument. The measured spread in the energy of ions reached up to 27 eV. V Martisovits, Fyzik Cas, 20 (2), 1970, 110-115. 22 1489. Thermal gauge for high vacuum to 10 6 torr. (USSR) Construction of a heat-conductivity vacuum gauge is described which can be used for measurement of pressure down to high vacuum range. B P Kozyrev, IzvLeningr Elektrotekh lust, 94, 1970, 20-23 (in Russian). 22 : 30 1490. Arrangement for mass-spectroscopic composition analysis of molecular beams of condensing materials with the aid of instrument KM 1. (USSR) An arrangement for investigating the composition of molecular beams, bombarding a substrate during vacuum evaporation, is described which contains a quadrupole mass spectrometer and a vacuum evaporator. The cross beam ion source of the mass spectrometer is placed above the evaporator in the vacuum chamber. A shield, controlled electromagnetically, is placed between the evaporator and the ion source. Calibration of the mass spectrometer for determination of the evaporation rate from the signal of the quadrupole is performed with the aid of a microinterferometer. The microinterferometer is used for determination of thickness of the deposited layers. In the evaporation of complex materials, which have a greater number of isotopes, and for condensation coefficients considerably differing from unity, the relationship between the output signal of the quadrupole and the evaporation rate is complex. Mass spectra obtained for evaporation of copper from a molybdenum boat at 1.8× 10-5 torr are presented. The minimum detectable evaporation rate for copper was 4 × 10-2 A./sec. It is demonstrated that the quadrupole mass spectrometer can be used for measurement of molecular beam intensities in a broad range of 0.04 to above 100 /~/sec of copper. G I Slobodenyuk et al, Zavodsk Lab, 37 (4), 1971,492-494 (in Russian). 22 1491. Manometric glass vessel with plane diaphragm. (USSR) A manometric glass vessel separated into two parts by a plane diaphragm is described. It is suitable for pressure measurement in systems placed in a thermostat. A P Alekseev et al, Zavodsk Lab, 37 (5), 1971, 627 (in Russian). 22 1492. Simple diaphragm gauge. (USSR) Construction of a simple diaphragm vacuum gauge is described. The stationary electrode is coated by a thin polymer film, less than 1 micron thick deposited in glow discharge plasma. The circuit diagram of the gauge is presented. L S Tuzov and A B Lipatov, Zavodsk Lab, 37 (5), 1971, 625-626 (in
Russian).