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648. Formation of secondary electron emission amplified by a field and the influence of internal and external suction fields on the emission
Classified
abstracts
647460
electron beam passing through trolling the gas pressure in the theory of this device, patented S D Gvozdover and V L Bulat, 154-l 55 (in Russian).
a gas discharge with tuning by conrange of lo+ to 1O-2 torr. The basic in USSR in 1947, is discussed. Radiotekh Elektron, 13 (l), Jan 1968,
18 647. Investigation of plasma microwave radiation in the process of beam instability development. (USSR) Radiation of 850 and 9,000 MHz was measured from a plasma produced by a pulse electron beam in a magnetic field at 5 x lO-3 torr. On both frequencies, after a single short pulse of intense radiation, irregular bursts with intensity lower by 30 dB were observed throughout the entire duration of the electron beam pulse. K P Kirdyashev et al, Radiotekh Elektron, 13 (I), Jan 1968, 155-157 (in Russian). 18 648. Formation of secondary electron emission amplified by a field and the influence of internal and external suction fields on the emission. (USSR) The secondary electron emission coefficient of KC1 was measured in the following system. At the distance of 4 mm from the backing, a grid-shaped collector was mounted and dc pulses of 24 V were applied between the collector and the backing. For pulses below 1O-3 set no influence was observed but for pulses longer than 3 set the emission was about 5 times more intense. N L Yasnolop’skiy and A P Balashova, Radiotekh Elektron, 13 (l), Jan 1968, 177-179 (in Russian). 18 649. Solid body secondary electron emission with the large angles of incidence of a primary beam. (USSR) The secondary electron emission of Al, Ti, Ni, Ge, Ag and Ba was measured for primary incidence angles of 0 to 89” and for voltages up to 5 keV. I M Bronshteyn and V A Dolinin, Radiotekh Elektron, 13 (l), Jan 1968, 179-181 (in Russian). 18 650. The energy distribution of secondary electrons for large incidence angles of primaries. (USSR) The secondary electron energy distribution of Al, Ni, Ge, Ag, Ba and Be was measured for primary incidence angles of 0 to 87”. It is shown that the secondary output zone is about 10 atomic layers and that maxima in the energetic spectrum are not shifted by varying the incidence angle of primaries. I M Bronshtevn and V A Dolinin. Radiotekh Elektron. , 13 (1). .I, Jan 1968. 181-182 (in I&an). 18 651. Multielectron ionization in close collisions of Ar and Kr ions and atoms. (USSR) The angular and energy dependence of the charge fractions in Ar+ and Kr+ ion beams, produced in collision with Ar and Kr atoms, were measured for ion energies of 200 to 1,700 keV at angles of I to 1 I”. L I Pivovar et al, Zh Eksper Teor Fiz, 53 (6), Dee 1967, 1872-1878 (in Russian). 18 652. Current-convective instability of an electron beam in a plasma. (USSR) The passage of an electron beam, with a current of 0.8 to IO A, through a neutral air atmosphere at lo-” to 5 x 1O-4 torr, in a uniform magnetic field, produces a plasma which may be, under certain conditions, unstable. Transition to the unstable stage is accompanied by a sharp decrease of the current at the collector and by an intensive microwave radiation. The magnetic field exerts a stabilizing effect. M D Rayzer et al, Zh Eksper Teor Fiz, 53 (6), Dee 1967, 1891.-1900 (in Russian). 18 653. Sliding discharge on the surface of solid dielectrics in vacuum. (USSR) The surface breakdown voltage of polyethylene insulators was measured in air and at 3 x 10m5torr, using dc and pulse voltages. The breakdown voltage in vacuum only slightly depends on the discharge path length: for 25 mm the breakdown voltage is 120 kV and for 100 mm is 135 kV. The use of sectional insulators is the only effective means for obtaining higher values of the breakdown voltages. P N Dashuk et al, Izv VUZ Fiz, 10 (12), 1967, 138-140 (in Russian).
18 654. Acceleration of charged particles in plasma. (USSR) This review article deals with the excitation of waves in plasma by means of an electron beam as it is used in high-energy particle accelerators. Ya B Faynberg, Uspekhi Fiz Nauk, 93 (4), Dee 1967, 617-631 (in Russian). 18
655. Characteristics of a reflex discharge in hydrogen in a magnetic field. (Czechoslovakia1 The properties of an extensive reflex discharge with one heated and one cold cathode, in a magnetic field up to 1,500 G, in hydrogen at lO-3 to 1Oe1 torr, were determined. Special interest was taken in the origin of low-frequency rotational instability and of hf oscillations in the frequency band up to 30 MHz. J Datlov et al, Czech J Phys, B 18 (l), 1968, 75-85 (in English). I8 656. Microwave investigation of acoustic waves in low-pressure plasma. (Czechoslovakia1 kcoustic waves with a frequency of 172 Hz were mechanically excited in the weakly ionized plasma of air and neon discharge and the periodic charges in electron distribution were measured by the microwave method. M Sicha et al, Czech J Phys, B 18 (l), 1968, 86-90 (in English). 18 657. Electron emission from sandwich cathodes with mica dielectric layer. (Czechoslovakia) The leakage and emission currents were measured for sandwich cathodes with a mica layer thickness of 0.6 to 11 microns and an upper gold electrode thickness of 200 A. The leakage characteristics were readily reproducible but the field emission currents were unstable and at higher voltages slow oscillations were observed. L Eckertova and J Jiskra, Czech J Phys, B 18 (I), 1968, 131-137 (in English).
II. Vacuum
apparatus
and auxiliaries
20. PUMPING SYSTEMS 20 : 34 Space applications of cryogenic technology. See abstract number 747. 20 : 62 658. Versatile vacuum apparatus for student practical work. (USSR) A simple glass apparatus is described containing mechanical. sorption and diffusion pumps, McLeod, Pirani and ionization gauges, iraps, artificial leaks and a bell jar, At Kazan State University, USSR, these systems are used for training students in high vacuum practical work. R B Tagirov et al, fzv VUZ Fiz, 10 (12), 1967, 120-121 (in Russian). 20 659. A multistage vacuum system. (USSR) A new form of multistage vacuum system (ejecting the evacuated gas into the atmosphere and containing pumps of the steam-jet type) is described. In the new system, the steam-jet pumps are connected in parallel to a built-in boiler supplied with condensate from the condenser of the final stage. This arrangement raises the economic level of the equipment and enables the whole operation to be carried out in a single closed cycle. The use of a built-in boiler makes the apparatus fully autonomous under laboratory and industrial conditions. The short pipelines required, the low over-all weight, and the possibility of introducing automatic control make this system particularly economic for large-scale use. A B Tseitlin, USSR Patent 189508, Appl22nd Ott 1965, Pub1 10th Jan 1967. 21. PUMPS AND PUMP FLUIDS 21 660. Method of measuring the backstreaming from mechanical drives in oil diffusion pumps, using a radioactive tracer. (Germany) Current literature on the backstreaming from mechanical drive mechanisms are reviewed and the problems associated with incor295
abstracts
647460
electron beam passing through trolling the gas pressure in the theory of this device, patented S D Gvozdover and V L Bulat, 154-l 55 (in Russian).
a gas discharge with tuning by conrange of lo+ to 1O-2 torr. The basic in USSR in 1947, is discussed. Radiotekh Elektron, 13 (l), Jan 1968,
18 647. Investigation of plasma microwave radiation in the process of beam instability development. (USSR) Radiation of 850 and 9,000 MHz was measured from a plasma produced by a pulse electron beam in a magnetic field at 5 x lO-3 torr. On both frequencies, after a single short pulse of intense radiation, irregular bursts with intensity lower by 30 dB were observed throughout the entire duration of the electron beam pulse. K P Kirdyashev et al, Radiotekh Elektron, 13 (I), Jan 1968, 155-157 (in Russian). 18 648. Formation of secondary electron emission amplified by a field and the influence of internal and external suction fields on the emission. (USSR) The secondary electron emission coefficient of KC1 was measured in the following system. At the distance of 4 mm from the backing, a grid-shaped collector was mounted and dc pulses of 24 V were applied between the collector and the backing. For pulses below 1O-3 set no influence was observed but for pulses longer than 3 set the emission was about 5 times more intense. N L Yasnolop’skiy and A P Balashova, Radiotekh Elektron, 13 (l), Jan 1968, 177-179 (in Russian). 18 649. Solid body secondary electron emission with the large angles of incidence of a primary beam. (USSR) The secondary electron emission of Al, Ti, Ni, Ge, Ag and Ba was measured for primary incidence angles of 0 to 89” and for voltages up to 5 keV. I M Bronshteyn and V A Dolinin, Radiotekh Elektron, 13 (l), Jan 1968, 179-181 (in Russian). 18 650. The energy distribution of secondary electrons for large incidence angles of primaries. (USSR) The secondary electron energy distribution of Al, Ni, Ge, Ag, Ba and Be was measured for primary incidence angles of 0 to 87”. It is shown that the secondary output zone is about 10 atomic layers and that maxima in the energetic spectrum are not shifted by varying the incidence angle of primaries. I M Bronshtevn and V A Dolinin. Radiotekh Elektron. , 13 (1). .I, Jan 1968. 181-182 (in I&an). 18 651. Multielectron ionization in close collisions of Ar and Kr ions and atoms. (USSR) The angular and energy dependence of the charge fractions in Ar+ and Kr+ ion beams, produced in collision with Ar and Kr atoms, were measured for ion energies of 200 to 1,700 keV at angles of I to 1 I”. L I Pivovar et al, Zh Eksper Teor Fiz, 53 (6), Dee 1967, 1872-1878 (in Russian). 18 652. Current-convective instability of an electron beam in a plasma. (USSR) The passage of an electron beam, with a current of 0.8 to IO A, through a neutral air atmosphere at lo-” to 5 x 1O-4 torr, in a uniform magnetic field, produces a plasma which may be, under certain conditions, unstable. Transition to the unstable stage is accompanied by a sharp decrease of the current at the collector and by an intensive microwave radiation. The magnetic field exerts a stabilizing effect. M D Rayzer et al, Zh Eksper Teor Fiz, 53 (6), Dee 1967, 1891.-1900 (in Russian). 18 653. Sliding discharge on the surface of solid dielectrics in vacuum. (USSR) The surface breakdown voltage of polyethylene insulators was measured in air and at 3 x 10m5torr, using dc and pulse voltages. The breakdown voltage in vacuum only slightly depends on the discharge path length: for 25 mm the breakdown voltage is 120 kV and for 100 mm is 135 kV. The use of sectional insulators is the only effective means for obtaining higher values of the breakdown voltages. P N Dashuk et al, Izv VUZ Fiz, 10 (12), 1967, 138-140 (in Russian).
18 654. Acceleration of charged particles in plasma. (USSR) This review article deals with the excitation of waves in plasma by means of an electron beam as it is used in high-energy particle accelerators. Ya B Faynberg, Uspekhi Fiz Nauk, 93 (4), Dee 1967, 617-631 (in Russian). 18
655. Characteristics of a reflex discharge in hydrogen in a magnetic field. (Czechoslovakia1 The properties of an extensive reflex discharge with one heated and one cold cathode, in a magnetic field up to 1,500 G, in hydrogen at lO-3 to 1Oe1 torr, were determined. Special interest was taken in the origin of low-frequency rotational instability and of hf oscillations in the frequency band up to 30 MHz. J Datlov et al, Czech J Phys, B 18 (l), 1968, 75-85 (in English). I8 656. Microwave investigation of acoustic waves in low-pressure plasma. (Czechoslovakia1 kcoustic waves with a frequency of 172 Hz were mechanically excited in the weakly ionized plasma of air and neon discharge and the periodic charges in electron distribution were measured by the microwave method. M Sicha et al, Czech J Phys, B 18 (l), 1968, 86-90 (in English). 18 657. Electron emission from sandwich cathodes with mica dielectric layer. (Czechoslovakia) The leakage and emission currents were measured for sandwich cathodes with a mica layer thickness of 0.6 to 11 microns and an upper gold electrode thickness of 200 A. The leakage characteristics were readily reproducible but the field emission currents were unstable and at higher voltages slow oscillations were observed. L Eckertova and J Jiskra, Czech J Phys, B 18 (I), 1968, 131-137 (in English).
II. Vacuum
apparatus
and auxiliaries
20. PUMPING SYSTEMS 20 : 34 Space applications of cryogenic technology. See abstract number 747. 20 : 62 658. Versatile vacuum apparatus for student practical work. (USSR) A simple glass apparatus is described containing mechanical. sorption and diffusion pumps, McLeod, Pirani and ionization gauges, iraps, artificial leaks and a bell jar, At Kazan State University, USSR, these systems are used for training students in high vacuum practical work. R B Tagirov et al, fzv VUZ Fiz, 10 (12), 1967, 120-121 (in Russian). 20 659. A multistage vacuum system. (USSR) A new form of multistage vacuum system (ejecting the evacuated gas into the atmosphere and containing pumps of the steam-jet type) is described. In the new system, the steam-jet pumps are connected in parallel to a built-in boiler supplied with condensate from the condenser of the final stage. This arrangement raises the economic level of the equipment and enables the whole operation to be carried out in a single closed cycle. The use of a built-in boiler makes the apparatus fully autonomous under laboratory and industrial conditions. The short pipelines required, the low over-all weight, and the possibility of introducing automatic control make this system particularly economic for large-scale use. A B Tseitlin, USSR Patent 189508, Appl22nd Ott 1965, Pub1 10th Jan 1967. 21. PUMPS AND PUMP FLUIDS 21 660. Method of measuring the backstreaming from mechanical drives in oil diffusion pumps, using a radioactive tracer. (Germany) Current literature on the backstreaming from mechanical drive mechanisms are reviewed and the problems associated with incor295