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754. Exo-electron emission of silicon and germanium after bombardment by protons of low energy
Classified
abstracts
‘747-160
laser welding arc shown in comparison with electrical contact welding. S G Bruk et al, t%c~ro/ric 7i~c~lrtrolo~~, Sciewt-Tech Collect, TechIW/CI~J~and Organizatim of’ Prodrrctiotl,No 3, 197 I, 9-17 (in Russian).
electron emission are observed after achange in direction of bombardment. 0 I Kapusta et al, Zzv AN SSSR Srr Fiz, 35 (2), 1971, 261-267 (i/r Russian).
31 747. Stability of photomultipliers. (Czechoslovakia) The results of an experimental investigation of stability of photomultiplier parameters.as dependent on &rrent load and temperature variations, are reported.. The stability of Sb-Na-K photocathode and that of the twelve-stage “Venetian blind” dynode system composed of AgMg alloy are treated separately. Causes of insufficient stability in photomultipliers are discussed in detail. M Jedlicka and J Raus, ‘Testa Electronics, 4 (4), 191 I, 99-106.
33 753. Secondary emission of some dielectric and semiconducting films (USSR) under bombardment by Na and K atoms and ions. Secondary electron emission, positive and negative ion emission are investieated for films of KCI. RbBr, Csl. Se and CdTe on MO and W. under bombardment by 30 tb 2500’eV ions and neutral atoms of Na and K. The measurements were performed by the oscillographic method of double modulation during the process of continuous deposition of the films. All three emissions have been observed simultaneously. The obtained results show that electron emission from dielectric films bombarded by atoms of alkali metals is higher than that when bombarded by ions of the same elements. U A Arifov et al, Izv AN SSSR Ser Fir, 35 (2), 1971, 248-251 (in Russian).
33. GENERAL
PHYSICS
AND ELECTRONICS 33
745. Field emission studies on clean symmetrical surfaces of cadmium sulphide. (Germany) Clean smooth symmetrical field emission patterns of CdS single crystals of about 2.6 x IO” ohm cm bulk resistivity are obtained by a cleaning procedure based upon hydrogen-promoted field evaporation at room temperature. A metallic cell equipped with a channel plate and with possibility of examination of four tips in one bake-out run is used. Besides the use as ion image intensifier, the channel plate allows, in a single cell, examination of ion and electron patterns. A residual gas pressure of lOm10 torr is attained in the cell before hydrogen admission. The best image voltage at 77°K is easily reproducible and by heating at about Il20”K, faceting occurs. The value 4.97 eV of the electron affinity is calculated from the Fowler-Nordheim equation modified for the case of a degenerate surface with field penetration. The Fowler-Nordheim plot shows a hysteresis at fields higher than 4 x IO’ V cm-‘; this could be explained among other interpretations by an adsorption starting at high fields. Under conditions of severe contamination, the work function increases to 1.59 eV. J Marien and J Loosveldt, Ph_~x Stat Sol (a), 8 (I). Nov I97 I, 213-22 I . 33 749. Investigation of photoelectron emission of low-molecular weight organic semiconductors. (USSR) Photoelectron emission from vacuum-deposited thin films of lowmolecular weight organic semiconductors is investigated in vacuum at IO-” to IO-* torr with the aid of a spherical capacitor. An analysis of influence of surface states on the photoelectron emission is given. The results are used to construct energy diagrams of the investigated materials. A I Belkind and S B Aleksandrov, IZV n N SSSR Seu Fiz, 35 (2), I97 I, 319-322 (in Russian). 33 750. Space and energy distributions of ions scattered by single crystal. (USSR) Changes in the character of the space and energy distributions of Rb+ ions scattered by W or MO single crystals are investigated as a function of orientation and temperature of the target, in the range of primary ion energies of 0.5 to 5 keV. Experimental results are discussed. U A Arifov and A A Aliev, IZVAN SSSR Ser Fiz, 35 (2), 1971, 384-388 (in Russian). 33 751. Anisotropy of secondary electron emission on transmission of Li+ ions through Cu single crystals. (USSR) Secondary ion-electron emission on transmission of lithium ions through oriented vacuum deposited thin films of copper on NaCl substrates is investigated in a vacuum apparatus. Experimental results are discussed. U A Arifov et al, Izr AN SSSR Ser Fiz, 35 (2), 1971, 252-254 (in Russia/?). 33 752. Angular and temperature dependences of the secondary emission from some single crystals bombarded by argon ions. (USSR) The results of an experimental investigation of the secondary ionelectron emission from single crystals of semiconductors and metals as a function of target temperature and incidence angle of argon ions, are reported. The experiments were performed in vacuum at residual gas pressure of 5 \\ IO-’ torr. Time changes in the coefficient of ion-
33 754. Exo-electron emission of silicon and germanium after bombardment by protons of low energy. (Germany) Exo-electron emission of silicon and germanium after bombardment by 500 keV protons is investigated in a vacuum chamber evacuated to 5 x 10e5 torr. Experimental results are discussed. (USSR) A G Zdanovich et al, Phys Stat Sol (a), 8 (I), Nov 1971, K27-K29. 33 755. Penetration of low-energy electrons and positrons in lead and aluminium. (USSR) The penetration of electrons and positrons, with energies of 285 to 435 keV, in lead and aluminium, are investigated. The experimental vacuum arrangement is described. It is found that positrons have higher penetration than electrons. E G Bertman et al, Zzv VUZ Fiz, No 8, 1971, 135-137 (in Russian). 33 756. Measurements of the electric field distribution on semiconductor surfaces using the electron mirror microscope. (Germany) A method of analysis of a surface field structure on semiconductor surfaces in vacuum using the electron mirror microscope is described. (Poland) T Warminski and I Glass, Phys Sfat Sol (a), 8 (i), Nov 1971, K l7-K20. 33 757. Production of electron-beam probes with the aid of an electron field emitter and magneto-optics. (USSR) Prospective utilization of field cathodes for producing electron probes are considered. The possibility of utilizing a tungsten field emitter for production of electron beams of 5 x IO-* A with a diameter of 1 /cm is demonstrated experimentally in a device with base pressure of 5 X lO-9 torr. I P Zhizhin et al, Izv AN SSSR Ser Fiz, 35 (2), 1971, 302-306 (i/f Russian). 33 758. Sensitive balance with remote recording. (USSR) Construction of an automatic quartz balance with an inductive sensor for measurement in vacuum or in a small gas flow is described. The sensitivity of the balance is 5 x 10e4 g. I Yu Babkin and D F Korobkin, Zavodsk Lab, 37 (6), 197 I, 743-744 (in Russian). 33 759. An arrangement for investigation of structure of microvolumes by Kossel reflection method. (USSR) A vacuum arrangement for investigating the structure of very small samples by the X-ray reflection Kossel method is described. Vacuum systems allow independent evacuation of the photographic chamber and the sample chamber to pressures of 10m4 to 10m5 torr. A I Pekarev et al, Zavodsk Lab, 37 (6), 197 I, 739-740 (in Russian). 33 760. Ion irradiation damage of silicon in the transmission electron microscope. (Germany) Ion irradiation damage of silicon samples in the transmission electron microscope operating at 100 kV is studied. It is shown that the studied defects in Si specimens are produced by high energy negative ions originating at the hot filament or in the anode-cathode space. (Switzerland). M J Hill, P& Stat Sol (a), 8 (I ), Nnv I97 1. 199-204. 245
abstracts
‘747-160
laser welding arc shown in comparison with electrical contact welding. S G Bruk et al, t%c~ro/ric 7i~c~lrtrolo~~, Sciewt-Tech Collect, TechIW/CI~J~and Organizatim of’ Prodrrctiotl,No 3, 197 I, 9-17 (in Russian).
electron emission are observed after achange in direction of bombardment. 0 I Kapusta et al, Zzv AN SSSR Srr Fiz, 35 (2), 1971, 261-267 (i/r Russian).
31 747. Stability of photomultipliers. (Czechoslovakia) The results of an experimental investigation of stability of photomultiplier parameters.as dependent on &rrent load and temperature variations, are reported.. The stability of Sb-Na-K photocathode and that of the twelve-stage “Venetian blind” dynode system composed of AgMg alloy are treated separately. Causes of insufficient stability in photomultipliers are discussed in detail. M Jedlicka and J Raus, ‘Testa Electronics, 4 (4), 191 I, 99-106.
33 753. Secondary emission of some dielectric and semiconducting films (USSR) under bombardment by Na and K atoms and ions. Secondary electron emission, positive and negative ion emission are investieated for films of KCI. RbBr, Csl. Se and CdTe on MO and W. under bombardment by 30 tb 2500’eV ions and neutral atoms of Na and K. The measurements were performed by the oscillographic method of double modulation during the process of continuous deposition of the films. All three emissions have been observed simultaneously. The obtained results show that electron emission from dielectric films bombarded by atoms of alkali metals is higher than that when bombarded by ions of the same elements. U A Arifov et al, Izv AN SSSR Ser Fir, 35 (2), 1971, 248-251 (in Russian).
33. GENERAL
PHYSICS
AND ELECTRONICS 33
745. Field emission studies on clean symmetrical surfaces of cadmium sulphide. (Germany) Clean smooth symmetrical field emission patterns of CdS single crystals of about 2.6 x IO” ohm cm bulk resistivity are obtained by a cleaning procedure based upon hydrogen-promoted field evaporation at room temperature. A metallic cell equipped with a channel plate and with possibility of examination of four tips in one bake-out run is used. Besides the use as ion image intensifier, the channel plate allows, in a single cell, examination of ion and electron patterns. A residual gas pressure of lOm10 torr is attained in the cell before hydrogen admission. The best image voltage at 77°K is easily reproducible and by heating at about Il20”K, faceting occurs. The value 4.97 eV of the electron affinity is calculated from the Fowler-Nordheim equation modified for the case of a degenerate surface with field penetration. The Fowler-Nordheim plot shows a hysteresis at fields higher than 4 x IO’ V cm-‘; this could be explained among other interpretations by an adsorption starting at high fields. Under conditions of severe contamination, the work function increases to 1.59 eV. J Marien and J Loosveldt, Ph_~x Stat Sol (a), 8 (I). Nov I97 I, 213-22 I . 33 749. Investigation of photoelectron emission of low-molecular weight organic semiconductors. (USSR) Photoelectron emission from vacuum-deposited thin films of lowmolecular weight organic semiconductors is investigated in vacuum at IO-” to IO-* torr with the aid of a spherical capacitor. An analysis of influence of surface states on the photoelectron emission is given. The results are used to construct energy diagrams of the investigated materials. A I Belkind and S B Aleksandrov, IZV n N SSSR Seu Fiz, 35 (2), I97 I, 319-322 (in Russian). 33 750. Space and energy distributions of ions scattered by single crystal. (USSR) Changes in the character of the space and energy distributions of Rb+ ions scattered by W or MO single crystals are investigated as a function of orientation and temperature of the target, in the range of primary ion energies of 0.5 to 5 keV. Experimental results are discussed. U A Arifov and A A Aliev, IZVAN SSSR Ser Fiz, 35 (2), 1971, 384-388 (in Russian). 33 751. Anisotropy of secondary electron emission on transmission of Li+ ions through Cu single crystals. (USSR) Secondary ion-electron emission on transmission of lithium ions through oriented vacuum deposited thin films of copper on NaCl substrates is investigated in a vacuum apparatus. Experimental results are discussed. U A Arifov et al, Izr AN SSSR Ser Fiz, 35 (2), 1971, 252-254 (in Russia/?). 33 752. Angular and temperature dependences of the secondary emission from some single crystals bombarded by argon ions. (USSR) The results of an experimental investigation of the secondary ionelectron emission from single crystals of semiconductors and metals as a function of target temperature and incidence angle of argon ions, are reported. The experiments were performed in vacuum at residual gas pressure of 5 \\ IO-’ torr. Time changes in the coefficient of ion-
33 754. Exo-electron emission of silicon and germanium after bombardment by protons of low energy. (Germany) Exo-electron emission of silicon and germanium after bombardment by 500 keV protons is investigated in a vacuum chamber evacuated to 5 x 10e5 torr. Experimental results are discussed. (USSR) A G Zdanovich et al, Phys Stat Sol (a), 8 (I), Nov 1971, K27-K29. 33 755. Penetration of low-energy electrons and positrons in lead and aluminium. (USSR) The penetration of electrons and positrons, with energies of 285 to 435 keV, in lead and aluminium, are investigated. The experimental vacuum arrangement is described. It is found that positrons have higher penetration than electrons. E G Bertman et al, Zzv VUZ Fiz, No 8, 1971, 135-137 (in Russian). 33 756. Measurements of the electric field distribution on semiconductor surfaces using the electron mirror microscope. (Germany) A method of analysis of a surface field structure on semiconductor surfaces in vacuum using the electron mirror microscope is described. (Poland) T Warminski and I Glass, Phys Sfat Sol (a), 8 (i), Nov 1971, K l7-K20. 33 757. Production of electron-beam probes with the aid of an electron field emitter and magneto-optics. (USSR) Prospective utilization of field cathodes for producing electron probes are considered. The possibility of utilizing a tungsten field emitter for production of electron beams of 5 x IO-* A with a diameter of 1 /cm is demonstrated experimentally in a device with base pressure of 5 X lO-9 torr. I P Zhizhin et al, Izv AN SSSR Ser Fiz, 35 (2), 1971, 302-306 (i/f Russian). 33 758. Sensitive balance with remote recording. (USSR) Construction of an automatic quartz balance with an inductive sensor for measurement in vacuum or in a small gas flow is described. The sensitivity of the balance is 5 x 10e4 g. I Yu Babkin and D F Korobkin, Zavodsk Lab, 37 (6), 197 I, 743-744 (in Russian). 33 759. An arrangement for investigation of structure of microvolumes by Kossel reflection method. (USSR) A vacuum arrangement for investigating the structure of very small samples by the X-ray reflection Kossel method is described. Vacuum systems allow independent evacuation of the photographic chamber and the sample chamber to pressures of 10m4 to 10m5 torr. A I Pekarev et al, Zavodsk Lab, 37 (6), 197 I, 739-740 (in Russian). 33 760. Ion irradiation damage of silicon in the transmission electron microscope. (Germany) Ion irradiation damage of silicon samples in the transmission electron microscope operating at 100 kV is studied. It is shown that the studied defects in Si specimens are produced by high energy negative ions originating at the hot filament or in the anode-cathode space. (Switzerland). M J Hill, P& Stat Sol (a), 8 (I ), Nnv I97 1. 199-204. 245