Classified abstracts 1549-1564

M R Aynbund et al, Elektron Tekh Elektronluch Fotoelektr Prib, 2, 1970, 11-15 (in Russian).

31 1549. Protection of ion gun electrodes against destruction on vacuum breakdown. (USSR) The conditions for instability in the operation of an ion gun with gas discharge, are considered. Utilization of a vacuum diode with a pro- nounced saturation region with lanthanum bexaboride cathode instead of a protective resistance in the ion gun circuit allows broaden- ing of the stable region of the ion gun operation. V F Kuzovlev and M M Bachmanov, Prib Tekh Eksper, No 1, 1971, 188-190 (in Russian).

31 1550. Investigation of the mechanism of electrical breakdown in high voltage pulsed modulator devices and ways of increasing the electrical strength of these devices. (USSR) The results of investigation of the mechanism of breakdown in pulsed high-voltage modulator vacuum devices are presented and the ways of increasing the electrical strength of these devices based on destruction of deposits on the anode by electron bombardment or utilization of anodes with ribs of molybdenum and tantalum, are discussed. P V Poshekhonov et al, Elektron Tekh Gener Modul Rentgen Prib, 3, 1969, 33-42 (in Russian).

31 1551. Influence of a transverse magnetic field on an electron beam at the initial stage of vacuum breakdown. (USSR) The influence of a transverse magnetic field on the conductivity growth processes arising at the breakdown of vacuum gaps is investi- gated. The experimental arrangement is described. The experiments were carried out in nonuniform field with a point cathode and plane anode at a pressure of 10 -n torr. The interelectrode gap was varied from 0.5 to 1.2 ram. Voltage pulses with amplitude of 20 to 50 kV, duration of 150 x 10 -9 sec and front of 10 -9 sec were used. It is found that magnetic field increases current oscillations in the gap during breakdown. R B Baksht and G A Mesyats, lzv VUZ Fiz, No 7, 1970, 144-146 (in Russian).

31 1552. Method for checking the evaporation rate of getters in ultrahigh frequency tubes type 6D13D and 6C50D. (USSR) In ultrahigh frequency electron tubes (type 6D13D and 6C50D) the evaporation-type getter is heated by passage of current through an iron-nickel holder, to which a capsule of the getter is welded. Since the getter is inside a metallic cathode cylinder, it is not possible to check getter temperature during degassing and flashing. During evaporation, barium is deposited on the metallic cathode cylinder and the process of barium evaporation is not monitored. The possibility of utilizing the thermionic emission from the getter to check the evaporation process is explored. To automate the getter evaporation process, an instrument containing a stabilizer for the thermionic emission of the heated getter has been developed. The stabilizer can maintain the thermionic emission at a determined level in the range of 10 -9 to 10 6 A. The evaporation time can be controlled by choice of the thermionic emission level. For the electron tubes tested, the evapo- ration time of the getter was 30 to 60 seconds. The monitoring method utilizes the variation of barium ion current produced by thermal ionization. The described technique enables improved processing of vacuum tubes. A A Sokolov, Elektron Tekh Priemno Usilit Lampy, 2, 1970, 88-91 (in Russian).

31 1553. Method for testing the adhesive strength of a porous component to a cathode core. (USSR) A method for testing the adhesive strength of a porous component to the cathode core of vacuum devices is described. N G Telezhkin et al, Elektron Tekh Priemno Usilit Lampy, 2, 1970, 87- 88 (in Russian).

31 1554. Chemical treatment of parts of ultrahigh devices after electric- spark operation. (USSR) The chemical cleaning of parts of vacuum devices, contaminated with pyrolysis products of petrol and metal carbides after electric-spark operation, is described. L A Dubenko and N S Sytilina, Elektron Tekh Elektron SVCh, 2, 1971, 106-110 (in Russian).

31 1555. Influence of anode processes on development of breakdown in oxide cathode devices. (USSR) The results of investigations on the electrical strength of vacuum devices with oxide cathodes are analyzed and the role of anode pro- cesses in breakdown development is considered. P V Poshekhonov and V I Melter, Elektron Tekh Gener Modul Rentgen Prib, 1, 1970, 5-17 (in Russian).

31 1556. Calculation of power incident on a screen grid of a beam tetrode due to radiation from cathode. (USSR) Using a computer, the portion of the power radiated from the cathode incident on the screen grid of a power tetrode, is calculated. M S Epshteyn, Elektron Tekh Gener Modul Rentgen Prib, 1, 1970, 43- 47 (in Russian).

31 1557. To the problem of high efficiency laser welding and treatment of parts of electro-vacuum devices. (USSR) Application of lasers for high efficiency technological operations in vacuum device manufacture is considered. A A Klimov and L A Radcbenko, Elektron Tekh Gener Modul Rentgen Prib, 1, 1970, 81-87 (in Russian).

31 1558. Stem-less pumping of medium-power transmitting tubes. (USSR) An equipment for stem-less pumping of medium-power vacuum tubes is described. Technological processes of evacuation and hermetization of devices are considered. Advantages of stem-less pumping are discussed. M N Pechatnikov et al, Elketron Tekh Gener Modul Rentgen Prib, 1, 1970, 88-93 (in Russian).

31 1559. Electron multiplier with continuous dynodes for detection of charged particles. (USSR) Construction of a channel electron multiplier consisting of two bent plates with distributed resistance, grid and anode is described. M A Ryabinina et al, Elektron Tekh Elektronluch Fotoelektr Prib, 4, 1970, 52-56 (in Russian).

31 1560. Influence of dissociation on inversion in pulsed CO= laser. (USSR) Inversion dynamics in pulsed CO2 laser is investigated. It is found that dissociation of CO2 molecules can significantly change the composition of the laser medium. An increase in the helium partial pressure reduces the influences of dissociation in gas flow lasers and decreases the inversion in sealed lasers. S S AIinpiev et al, Radiotekh Elektron, 15 (I1), 1970, 2361-2367 (in Russian).

31 1561. Anode electron currents in the firing stage of a pulsed discharge in high vacuum. (USSR) A method and results of calculation of the maximum density of the electron current which can flow to the anode in firing stage of a pulsed discharge in high vacuum, in a system containing a cold cathode with firing arrangement, are presented. A B Boym et al, Radiotekh Elektron, 15 (11), 1970, 2415-2417 (in Russian).

31 1562. Thermal treatment of glass by radiant heat, using an elliptical reflector. (USSR) Application of glass heat treatment, by thermal radiation with utilization of an elliptical reflector, in the manufacture of electro- vacuum devices, is examined. O G Smirnov et al, Elektron Tekh Tekhnol Organiz Proiz, 8, 1970, 60- 67 (in Russian).

31 1563. Choice of diameter of vacuum chamber for stem-less pumping of electro-vacuum devices. (USSR) Factors influencing the choice of the diameter of the vacuum chamber for stem-less pumping and hermetization of electro-vacuum devices are considered. S F Budnikov and V A Antonov, Elektron Tekh Tekhnol Organ Proizv, 8, 1970, 7-10 (in Russian).

31 1564. Utilization of vacuum systems with sorption traps for evacuation of travelling wave tubes. (USSR) It is shown that it is advantageous to use sorption traps in vacuum

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