- Email: [email protected]
1576. Mass spectrometric determination of the heats of formation and atomization of gaseous AuBO
Classified abstracts 1565-1578 systems intended for evacuation of travelling wave tubes. S G Bruk et al, Elektron Tekh Tekhnol OrganizProizv, 8, 1970, 11-16
(in Russian). 31 1565. Instrument for checking the inner configuration of envelope walls of cathode ray tubes. (USSR) An immersion method is described together with an instrument for observation of the inner configuration of the disc seal on the cone of a cathode ray envelope and also for the measurement of wall thickness in the seal zone. Yu I Vershinin et al, Optiko Mekh Prom, No 2, 1971, 62-63 (in
Russian). 31 1566. Electrostatic deposition of phosphors on glass substrates. (USSR) A method for electrostatic deposition of phosphors on glass substrates for electro-vacuum devices is described. It is shown that screens deposited with the aid of an electric field have by 35 to 45 per cent higher luminous intensity than those deposited by centrifuge. A P Androsov and T N Vasileva, Elektron Tekh Tekhnol Organ Proizv, 6, 1970, 28-31 (in Russian). 32. NUCLEONICS 32 1567. Investigation of ion current flowing from a two-lens accelerator. (USSR) The space distribution of ion currents of 1 kA magnitude and 2.5 keV energy, flowing out of a two-lens plasma accelerator, is investigated. The accelerator is intended as the first stage of an injector for thermonuclear purposes. The mass composition of the ion current is considered. I P Zubkov et al, Zh Tekh Fiz, 41 (5), 1971, 880-889 (in Russian). 32 1568. Approximate solution of electron motion in a linac. (Czechoslovakia) One of the possible design alternatives of a 5 MeV electron linear accelerator, with beam power of 800 W, is described. Electron dynamics are calculated using new simplifications and with the aid of a computer. Construction of the electron gun for the linac is illustrated. V Hlubucek, Tesla Electron, 4 (1), 1971, 8-15. 33. GENERAL PHYSICS AND ELECTRONICS 33 1569. Some characteristics of a Si target used as an image intensifier in an electron microscope. (Japan) The silicon diode array target is located inside an electron microscope column and directly bombarded with imaging electrons. A current gain of over 7000 is obtained when the target is bombarded with a high potential electron beam. Experimentally determined characteristics include: maximum value of current gain at the optimum beatn potential; with increasing target thickness, the optimum value of beam potential shifts to the higher potential region and the maximum current gain also increases while the resolution decreases; and the resolution may be restored by elevation of the beam potential. Television systems with the silicon target provide a large brightness intensification in the observed electron microscope image. The system is applicable over a wide range of beam potential (100-1000 kV) provided the optimum thickness is selected. H Todokoro et al, J Vae Soc Japan, 14 (5), 1971, 178-183 (in Japanese). 33 1570. Development of a high-speed mass spectrometer for ultrahigh vacuum studies of ion emission from metallic surfaces. (France) The experimental system is described in detail and results are presented for operation at pressures down to 10-9 torr. Mass spectra of negative ions and the energy spectrum of O - ions simultaneously emitted from several metallic targets are also presented. It is shown that a fine structure may be observed in energy distribution of the negative oxygen ion. S Paletto et al, Le Vide, 26 (I 52), March-April, 1971, 63-68 (in French). 33 1571. High-perveance three-electrode electron gun with prolonged life. (USSR) Increased life is obtained by utilization of barium-tungsten or impregnated cathodes which possess high emission and sufficient resis-
624
tance against ion bombardment. Fused silica insulating parts have good insulating properties at high temperatures. The life of this gun is 500 to 700 hours of continuous operation in ambient at pressure lower than 10-e tort. N S Zinchenko and I V Lopatin, Izv VUZ Radioelektron, 13 (11), 1970, 1379-1381 (in Russian). 33 1572. Field ion microscopic investigation of an intergranular streak in tungsten. (USSR) A transversal intergranular streak with relatively high stability has been observed during evaporation of a tungsten sample by an electric field in a field ion microscope. R I Garber et al, Izv VUZFiz, No 2, 1971, 122-123 (in Russian). 33 1573. The Compton effect and the absorption of power by space charge. (USSR) The Compton effect and the absorption of power from an electromagnetic wave by electrons forming space charge in a vacuum tube, are considered. The absorbed power and the increase in electron gas temperature are calculated. The possibility of measuring the intensity of powerful coherent light beams with the aid of a plane triode operating in the space charge region and evacuated to a pressure of 10 -e to 10-8 torr, is shown. O G Bokov and M V Yudovich, Izv VUZ Fiz, No 9, 1970, 95-99 (in
Russian). 33 1574. Laboratory technique of experimental arrangements for investigation of powerful electron beams. (Germany) Demountable envelopes and electron sources used in ultrahigh vacuum experimental arrangements for investigation of powerful electron beams are described. Large-size high-vacuum furnaces used for sealing ceramics to copper and high-temperature high-vacuum furnaces are dealt with. J Fisch et al, Wiss Z Techn Hochsch Ilmenau, 16 (4), 1970, 3 5 4 9 (in
German). 33 1575. Equipment for ion puncture of diaphragm apertures in the electron guns of television camera tubes. (USSR) Principle of action, construction and basic technical data of a new vacuum system are described which is used for ion puncture of diaphragm apertures in the electron guns of television camera tubes. A A Gurlev and A M Minkin, Elektron Tekh Elektronluch Fotoelektr Prib, 3, 1970, 75-80 (in Russian). 33 1576. Mass spectrometric determination of the heats of formation and atomization of gaseous AuBO. (USA) Mass spectrometric analysis was used to detect AuBO(g) during evaporation of Ce and Au from a boron nitride Knudsen cell. The heat of formation was determined by a third law method, for which the reaction equilibria are listed. The heats of formation and atomization calculated from the reaction enthalpies are listed. K A Gingerich and C Pupp, J Chem Phys, 54 (9), 1st May 1971, 37133716. 33 1577. Dynamics of the reaction of N + wi h H2. (USA) The reaction N + (H2,H)NH + was studied by measuring the velocity vector distribution of product ions formed when a collimated, massanalyzed beam of reactant ions impinges on a target gas. A magnetic mass spectrometer was used to produce the collimated beam. In the 2.5-8.1 eV range of initial relative energies, the reaction proceeds by a direct interaction mechanism with predominant forward scattering. The forward scattered N H ÷ is more excited internally than would be expected from the spectator stripping model, and the internal excitation markedly decreases as the scattering angle increases. E A Gislason et al, J Chem Phys, 54 (9), 1st May 1971, 3897-3901. 33 1578. Energy loss spectra of low-energy electrons scattered from thin solid molecular films. (USA) The electron impact spectrometer used in these measurements is described in some detail. The spectrometer operates as low as 1 eV and can monitor dynamic changes in electronic excitation crosssections in the important threshold region. Excitation of benzene to optically forbidden states, while highly probable near threshold, show a rapid fall-off in excitation probability at higher impact energies as compared to the optically allowed transition. In studies
(in Russian). 31 1565. Instrument for checking the inner configuration of envelope walls of cathode ray tubes. (USSR) An immersion method is described together with an instrument for observation of the inner configuration of the disc seal on the cone of a cathode ray envelope and also for the measurement of wall thickness in the seal zone. Yu I Vershinin et al, Optiko Mekh Prom, No 2, 1971, 62-63 (in
Russian). 31 1566. Electrostatic deposition of phosphors on glass substrates. (USSR) A method for electrostatic deposition of phosphors on glass substrates for electro-vacuum devices is described. It is shown that screens deposited with the aid of an electric field have by 35 to 45 per cent higher luminous intensity than those deposited by centrifuge. A P Androsov and T N Vasileva, Elektron Tekh Tekhnol Organ Proizv, 6, 1970, 28-31 (in Russian). 32. NUCLEONICS 32 1567. Investigation of ion current flowing from a two-lens accelerator. (USSR) The space distribution of ion currents of 1 kA magnitude and 2.5 keV energy, flowing out of a two-lens plasma accelerator, is investigated. The accelerator is intended as the first stage of an injector for thermonuclear purposes. The mass composition of the ion current is considered. I P Zubkov et al, Zh Tekh Fiz, 41 (5), 1971, 880-889 (in Russian). 32 1568. Approximate solution of electron motion in a linac. (Czechoslovakia) One of the possible design alternatives of a 5 MeV electron linear accelerator, with beam power of 800 W, is described. Electron dynamics are calculated using new simplifications and with the aid of a computer. Construction of the electron gun for the linac is illustrated. V Hlubucek, Tesla Electron, 4 (1), 1971, 8-15. 33. GENERAL PHYSICS AND ELECTRONICS 33 1569. Some characteristics of a Si target used as an image intensifier in an electron microscope. (Japan) The silicon diode array target is located inside an electron microscope column and directly bombarded with imaging electrons. A current gain of over 7000 is obtained when the target is bombarded with a high potential electron beam. Experimentally determined characteristics include: maximum value of current gain at the optimum beatn potential; with increasing target thickness, the optimum value of beam potential shifts to the higher potential region and the maximum current gain also increases while the resolution decreases; and the resolution may be restored by elevation of the beam potential. Television systems with the silicon target provide a large brightness intensification in the observed electron microscope image. The system is applicable over a wide range of beam potential (100-1000 kV) provided the optimum thickness is selected. H Todokoro et al, J Vae Soc Japan, 14 (5), 1971, 178-183 (in Japanese). 33 1570. Development of a high-speed mass spectrometer for ultrahigh vacuum studies of ion emission from metallic surfaces. (France) The experimental system is described in detail and results are presented for operation at pressures down to 10-9 torr. Mass spectra of negative ions and the energy spectrum of O - ions simultaneously emitted from several metallic targets are also presented. It is shown that a fine structure may be observed in energy distribution of the negative oxygen ion. S Paletto et al, Le Vide, 26 (I 52), March-April, 1971, 63-68 (in French). 33 1571. High-perveance three-electrode electron gun with prolonged life. (USSR) Increased life is obtained by utilization of barium-tungsten or impregnated cathodes which possess high emission and sufficient resis-
624
tance against ion bombardment. Fused silica insulating parts have good insulating properties at high temperatures. The life of this gun is 500 to 700 hours of continuous operation in ambient at pressure lower than 10-e tort. N S Zinchenko and I V Lopatin, Izv VUZ Radioelektron, 13 (11), 1970, 1379-1381 (in Russian). 33 1572. Field ion microscopic investigation of an intergranular streak in tungsten. (USSR) A transversal intergranular streak with relatively high stability has been observed during evaporation of a tungsten sample by an electric field in a field ion microscope. R I Garber et al, Izv VUZFiz, No 2, 1971, 122-123 (in Russian). 33 1573. The Compton effect and the absorption of power by space charge. (USSR) The Compton effect and the absorption of power from an electromagnetic wave by electrons forming space charge in a vacuum tube, are considered. The absorbed power and the increase in electron gas temperature are calculated. The possibility of measuring the intensity of powerful coherent light beams with the aid of a plane triode operating in the space charge region and evacuated to a pressure of 10 -e to 10-8 torr, is shown. O G Bokov and M V Yudovich, Izv VUZ Fiz, No 9, 1970, 95-99 (in
Russian). 33 1574. Laboratory technique of experimental arrangements for investigation of powerful electron beams. (Germany) Demountable envelopes and electron sources used in ultrahigh vacuum experimental arrangements for investigation of powerful electron beams are described. Large-size high-vacuum furnaces used for sealing ceramics to copper and high-temperature high-vacuum furnaces are dealt with. J Fisch et al, Wiss Z Techn Hochsch Ilmenau, 16 (4), 1970, 3 5 4 9 (in
German). 33 1575. Equipment for ion puncture of diaphragm apertures in the electron guns of television camera tubes. (USSR) Principle of action, construction and basic technical data of a new vacuum system are described which is used for ion puncture of diaphragm apertures in the electron guns of television camera tubes. A A Gurlev and A M Minkin, Elektron Tekh Elektronluch Fotoelektr Prib, 3, 1970, 75-80 (in Russian). 33 1576. Mass spectrometric determination of the heats of formation and atomization of gaseous AuBO. (USA) Mass spectrometric analysis was used to detect AuBO(g) during evaporation of Ce and Au from a boron nitride Knudsen cell. The heat of formation was determined by a third law method, for which the reaction equilibria are listed. The heats of formation and atomization calculated from the reaction enthalpies are listed. K A Gingerich and C Pupp, J Chem Phys, 54 (9), 1st May 1971, 37133716. 33 1577. Dynamics of the reaction of N + wi h H2. (USA) The reaction N + (H2,H)NH + was studied by measuring the velocity vector distribution of product ions formed when a collimated, massanalyzed beam of reactant ions impinges on a target gas. A magnetic mass spectrometer was used to produce the collimated beam. In the 2.5-8.1 eV range of initial relative energies, the reaction proceeds by a direct interaction mechanism with predominant forward scattering. The forward scattered N H ÷ is more excited internally than would be expected from the spectator stripping model, and the internal excitation markedly decreases as the scattering angle increases. E A Gislason et al, J Chem Phys, 54 (9), 1st May 1971, 3897-3901. 33 1578. Energy loss spectra of low-energy electrons scattered from thin solid molecular films. (USA) The electron impact spectrometer used in these measurements is described in some detail. The spectrometer operates as low as 1 eV and can monitor dynamic changes in electronic excitation crosssections in the important threshold region. Excitation of benzene to optically forbidden states, while highly probable near threshold, show a rapid fall-off in excitation probability at higher impact energies as compared to the optically allowed transition. In studies