- Email: [email protected]
67. Comparison of some secondary emission characteristics of single crystals and polycrystals
Classified
abstracts
56-66
graphite and pure graphite in vacuum. Experimental results are discussed. A P Kazantsev and T L Matskevich, Radiotekh Elekrron, 16 (4), 1971, 645-648 (in Russian). 18 56. Electron emission from single crystals of alkali halide compounds under bombardment with ions and atoms of inert gases. (USSR) The potential and kinetic emission of electrons from (100) faces of KBr, NaCl and LiF is investigated with bombardment by ions and atoms of He, Ne, Ar and Kr in the energy range 0.2 to 6 keV at sample temperatures of 350 to 380°C. The experimental vacuum apparatus contains an ion source with focusing lenses, a chargeexchange chamber, an electrostatic separator of ions and atoms and a detector of ions and atoms. The residual gas pressure was 1 Y lo-’ torr in the experimental apparatus. A monotonic increase of the coefficients of ion-electron and atom-electron emissions is found for increasing energy of primary particles. U A Arifov et al, Izv Akad Nauk SSSR Ser Fiz, 35 (3), 1971, 562-566 (in Russian).
18 57. Secondary electron emission of tungsten and molybdenum single crystals. (USSR) Secondary electron emission from the (111) and (110) faces of single crystal tungsten and the (100) and (110) faces of single crystal molybdenum is investigated in an experimental device at lo-’ torr, in the range of primary electron energies of 100 to 1500 eV, using the method of double modulation. The dependences of the total coefficient of secondary emission, the coefficient of true secondary electrons and the coefficients of elastically and inelastically reflected electrons on the primary electron energy are measured. U A Arifov et al, Izv Akad Nauk SSSR Ser Fiz, 35 (3), 1971, 56(r561 (in Russian). 18 58. Optical properties of modern multialkali photocathodes and their emission ability. (USSR) Optical properties of multialkali photocathodes are investigated and their influence on the photoelectron emission is discussed. V E Kondrashov et al, Izv Akad Nauk SSSR Ser Fiz, 35 (3), 1971,621623 (in Russian). 18 59. Investigation of photoelectron emission in vacuum ultraviolet
region. (USSR) Spectral distributions of the quantum yield in the region of 500 to 2500 A are measured for CuI, GaAs, CdS and Si, and the photoelectron work function of CuI is determined. Differential pumping in the vacuum monochromator gave a receiver chamber pressure of 1O-6 torr while in the chamber of the radiation source the pressure was 1 torr. Possible applications of the tested materials in radiation detectors are discussed. Zh Kh Khachatryan et al, Izv Akud Nauk SSSR Ser Fiz, 35 (3), 197 I, 624-626
(in Russian).
18 60. Energy distribution of photoelectrons and quantum yield of the
external photoeffect of barium and terbium films with different thicknesses. (USSR) Thickness dependences of the quantum yield of the external photoeffect, optical characteristics, and energy distribution of photoelectrons from barium and terbium films on quartz substrates are investigated. The pressure during Iayer deposition was 1 x lo--* torr and during measurement in a sealed glass experimental device the pressure was 2-3 x 1OW torr. It is found that the thickness dependences have maxima at the thickness of 50 A. The maxima are connected with optical properties of the layers and scattering of the photoelectrons. A R Shulman et al, Izv Akad Nuuk SSSR Ser Fir, 35 (3), 1971, 627631 (in Russian). 18 61. Thermionic emission of electrons on change of work function and formation of a surface double layer. (USSR) Thermionic emission from an insulated emitter is considered. A double electric layer is formed on its surface, the potential of which is determined in principle by the electron temperature. The surface emission layer causes the appearance of heavy ions moving with
32
ultrathermal velocities. Similar phenomena may arise at electric and laser explosions on boundary of solid or liquid phase/vacuum, and in some astrophysical processes. A K Musiu, Izv Akud Nuuk SSSR Ser Fiz, 35 (3), 1971, 636-640 (in Russian). 18 62. Imaging of a thermionic emitter in an emission microscope. (USSR)
Calculation of the redistribution of current density on the screen of an emission microscope due to contact microfields is performed. It is shown that this effect can cause considerable errors in the determination of local work function on the cathode surface from the image of a thermionic emitter in the emission microscope. N N Sedov, Izv Akud Nauk SSSR Ser Fiz, 35 (3), 1971, M-643 (in Russian). 18
(USSR) Electron emission from a tungsten sample excited by the radiation from a ruby laser, operated in the free generation regime, is investigated. The results indicate the possibility of a multiphoton mechanism of electron release for spike emission and a strong relation between integral heating of the target and losses of energy due to evaporation of material by spikes of radiation. U A Arifov et al, Izv Akud Nauk SSSR Ser Fiz, 35 (3), 197 I, 599-602 63. Integral and spike emissions excited by laser radiation.
(in Russian). IX 64. On the problem of emission uniformity of an oxide cathode in a
longitudinal magnetic field. (USSR) Uniformity of electron emission in a magnetic field at different regimes of oxide cathode operation is investigated in an experimental diode. It is found that irregularities in geometry of the oxide cathode surface considerably influences the uniformity of the emission current in the saturated current region. M V Krasinkova et al. Izv Akad Nuuk SSSR Ser Fiz. 35 (3). 1971. 603-606 (in Russian). 18 65. Comparison of variations in oxide cathode emission on drawing
direct current with variations in potential gradient in the oxide coating. (USSR) Regularities in time variations of potential gradient in dependence on temperature, cathode current and state of activation of the coating are investigated and compared with regularities in emission current decay to elucidate the mechanism of emission current decay in electron devices with oxide cathodes. Experimental results are discussed. V N Dudkin et al, Izv Akud Nuuk SSSR Ser Fiz, 35 (3), I97 I, 607.-6 I I (in Russinn). 18 66. Variations of the coefficient of secondary electron emission of
oxides under prolonged irradiation by electron beam. (USSR) Variation of the coefficient of secondary electron emission of alkalineearth metal oxides under prolonged bombardment by an electron beam is investigated in an experimental device at pressure of lo--’ to lo-* torr. Experimental results are discussed. A M Tyutitkov and M N Toiseva, Izv Akad Nuuk SSSR Ser Fiz, 35 (3), 1971, 571-577 (in Russian). 18 67. Comparison of some secondary emission characteristics of single
crystals and polycrystals. (USSR) It is shown that ordering of crystalline structure has a significant influence on the dependences of the coefficients of secondary emission of inelastically and elastically reflected electrons on the primary electron energy. A R Shulman et al, Izv Akud Nauk SSSR Ser Fiz, 35 (5), 1971, 10601063 (in Russian). 18 68. Role of defects in secondarv electron emission of efficient cathodes.
(USSR) Shape of the secondary electron current pulse is explored in the frequency range 50 Hz to 120 kHz while varying the urimarv nulsed current density from I to 100 mA/cmZ. Factois influencing the magnitude of the coefficient of secondary electron emission of efficient emitters are studied. V L Borisov and V N Lepeshinskaya, Izv Akud Nuuk SSSR Ser Fi:, 35 (5),1971, 1056-1059 (in Russiun).
abstracts
56-66
graphite and pure graphite in vacuum. Experimental results are discussed. A P Kazantsev and T L Matskevich, Radiotekh Elekrron, 16 (4), 1971, 645-648 (in Russian). 18 56. Electron emission from single crystals of alkali halide compounds under bombardment with ions and atoms of inert gases. (USSR) The potential and kinetic emission of electrons from (100) faces of KBr, NaCl and LiF is investigated with bombardment by ions and atoms of He, Ne, Ar and Kr in the energy range 0.2 to 6 keV at sample temperatures of 350 to 380°C. The experimental vacuum apparatus contains an ion source with focusing lenses, a chargeexchange chamber, an electrostatic separator of ions and atoms and a detector of ions and atoms. The residual gas pressure was 1 Y lo-’ torr in the experimental apparatus. A monotonic increase of the coefficients of ion-electron and atom-electron emissions is found for increasing energy of primary particles. U A Arifov et al, Izv Akad Nauk SSSR Ser Fiz, 35 (3), 1971, 562-566 (in Russian).
18 57. Secondary electron emission of tungsten and molybdenum single crystals. (USSR) Secondary electron emission from the (111) and (110) faces of single crystal tungsten and the (100) and (110) faces of single crystal molybdenum is investigated in an experimental device at lo-’ torr, in the range of primary electron energies of 100 to 1500 eV, using the method of double modulation. The dependences of the total coefficient of secondary emission, the coefficient of true secondary electrons and the coefficients of elastically and inelastically reflected electrons on the primary electron energy are measured. U A Arifov et al, Izv Akad Nauk SSSR Ser Fiz, 35 (3), 1971, 56(r561 (in Russian). 18 58. Optical properties of modern multialkali photocathodes and their emission ability. (USSR) Optical properties of multialkali photocathodes are investigated and their influence on the photoelectron emission is discussed. V E Kondrashov et al, Izv Akad Nauk SSSR Ser Fiz, 35 (3), 1971,621623 (in Russian). 18 59. Investigation of photoelectron emission in vacuum ultraviolet
region. (USSR) Spectral distributions of the quantum yield in the region of 500 to 2500 A are measured for CuI, GaAs, CdS and Si, and the photoelectron work function of CuI is determined. Differential pumping in the vacuum monochromator gave a receiver chamber pressure of 1O-6 torr while in the chamber of the radiation source the pressure was 1 torr. Possible applications of the tested materials in radiation detectors are discussed. Zh Kh Khachatryan et al, Izv Akud Nauk SSSR Ser Fiz, 35 (3), 197 I, 624-626
(in Russian).
18 60. Energy distribution of photoelectrons and quantum yield of the
external photoeffect of barium and terbium films with different thicknesses. (USSR) Thickness dependences of the quantum yield of the external photoeffect, optical characteristics, and energy distribution of photoelectrons from barium and terbium films on quartz substrates are investigated. The pressure during Iayer deposition was 1 x lo--* torr and during measurement in a sealed glass experimental device the pressure was 2-3 x 1OW torr. It is found that the thickness dependences have maxima at the thickness of 50 A. The maxima are connected with optical properties of the layers and scattering of the photoelectrons. A R Shulman et al, Izv Akad Nuuk SSSR Ser Fir, 35 (3), 1971, 627631 (in Russian). 18 61. Thermionic emission of electrons on change of work function and formation of a surface double layer. (USSR) Thermionic emission from an insulated emitter is considered. A double electric layer is formed on its surface, the potential of which is determined in principle by the electron temperature. The surface emission layer causes the appearance of heavy ions moving with
32
ultrathermal velocities. Similar phenomena may arise at electric and laser explosions on boundary of solid or liquid phase/vacuum, and in some astrophysical processes. A K Musiu, Izv Akud Nuuk SSSR Ser Fiz, 35 (3), 1971, 636-640 (in Russian). 18 62. Imaging of a thermionic emitter in an emission microscope. (USSR)
Calculation of the redistribution of current density on the screen of an emission microscope due to contact microfields is performed. It is shown that this effect can cause considerable errors in the determination of local work function on the cathode surface from the image of a thermionic emitter in the emission microscope. N N Sedov, Izv Akud Nauk SSSR Ser Fiz, 35 (3), 1971, M-643 (in Russian). 18
(USSR) Electron emission from a tungsten sample excited by the radiation from a ruby laser, operated in the free generation regime, is investigated. The results indicate the possibility of a multiphoton mechanism of electron release for spike emission and a strong relation between integral heating of the target and losses of energy due to evaporation of material by spikes of radiation. U A Arifov et al, Izv Akud Nauk SSSR Ser Fiz, 35 (3), 197 I, 599-602 63. Integral and spike emissions excited by laser radiation.
(in Russian). IX 64. On the problem of emission uniformity of an oxide cathode in a
longitudinal magnetic field. (USSR) Uniformity of electron emission in a magnetic field at different regimes of oxide cathode operation is investigated in an experimental diode. It is found that irregularities in geometry of the oxide cathode surface considerably influences the uniformity of the emission current in the saturated current region. M V Krasinkova et al. Izv Akad Nuuk SSSR Ser Fiz. 35 (3). 1971. 603-606 (in Russian). 18 65. Comparison of variations in oxide cathode emission on drawing
direct current with variations in potential gradient in the oxide coating. (USSR) Regularities in time variations of potential gradient in dependence on temperature, cathode current and state of activation of the coating are investigated and compared with regularities in emission current decay to elucidate the mechanism of emission current decay in electron devices with oxide cathodes. Experimental results are discussed. V N Dudkin et al, Izv Akud Nuuk SSSR Ser Fiz, 35 (3), I97 I, 607.-6 I I (in Russinn). 18 66. Variations of the coefficient of secondary electron emission of
oxides under prolonged irradiation by electron beam. (USSR) Variation of the coefficient of secondary electron emission of alkalineearth metal oxides under prolonged bombardment by an electron beam is investigated in an experimental device at pressure of lo--’ to lo-* torr. Experimental results are discussed. A M Tyutitkov and M N Toiseva, Izv Akad Nuuk SSSR Ser Fiz, 35 (3), 1971, 571-577 (in Russian). 18 67. Comparison of some secondary emission characteristics of single
crystals and polycrystals. (USSR) It is shown that ordering of crystalline structure has a significant influence on the dependences of the coefficients of secondary emission of inelastically and elastically reflected electrons on the primary electron energy. A R Shulman et al, Izv Akud Nauk SSSR Ser Fiz, 35 (5), 1971, 10601063 (in Russian). 18 68. Role of defects in secondarv electron emission of efficient cathodes.
(USSR) Shape of the secondary electron current pulse is explored in the frequency range 50 Hz to 120 kHz while varying the urimarv nulsed current density from I to 100 mA/cmZ. Factois influencing the magnitude of the coefficient of secondary electron emission of efficient emitters are studied. V L Borisov and V N Lepeshinskaya, Izv Akud Nuuk SSSR Ser Fi:, 35 (5),1971, 1056-1059 (in Russiun).