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1492. Ion density in electron beams
Classified
abstracts
1483-1499
In the apparatus described, the tungsten cathode is heated by the electron beam. Particulars are given of the electrodes used and of the beam currents and current densities obtainable with an emission surface temperature of 2900°K. An ion-separating electron gun is used which can be attached to the welding chamber at any angle. Examples of the various welds that can be produced are illustrated and discussed. Optical viewing of the welding operation is possible. E B Bas et al, Schweiz Arch, 31 (2), 1965, 40-49. 33 : 37 1483. Electron beam in modem vacuum metallurgy. (USSR) B E Paton and B A Movchan, Vest An SSR, 34 (I), 1965, 25-29, (in Russian). 33
1484. Low temperature Physics. J G Daunt. et al. (Editors). Proceed&s on Low Temper&re Phy&s, Columbus, Plenum Press, New York, 1965.
9th International Conference Ohio, 1964, Published by 33
1485. Description of invention 171471. Cathode of electrovacuum apparatus. (USSR) A new “sandwich” cathode for electronic vacuum systems is described. This comprises a metal base covered with a dielectric film, above which a thin conducting layer is deposited. The thickness of the conducting film is so chosen to allow electrons to pass through it from the dielectric. The conducting film is held at a negative potential with respect to the metal base. This cathode gives a high current density suitable for beam-type systems operating at UHF; the noise level is low and the lifetime substantial. A typical example uses an aluminium base, bearing its normal oxide film, with another metal deposited on top of this. V V Shcherbakov, Class Zld, 1304, MPK H 01 j, (in Russian). 33 1486. Description of invention 168371. Field-emission photocathode. (USSR)
A new photocathode composed of a germanium-nickel alloy and operating on the basis of field-emission photoconductivity is described. In this the distribution of the field between cathode and vacuum gap is affected by incoming light. Features of this photocathode include a spectral characteristic extending to 3.3 p, high sensitivity, and a non-linear lux/ampere characteristic, enabling the cathode to be used under very strong illumination. The cathode is made in the form of a sharp point in order to create a strong electric field; it operates stably and for long periods at a pressure of lo+’ torr. P G Borzyak, et al, Class 2ld, 29a0, MPK H 01 I, (in Russian). 33
1487. Handbook for electron tube and vacuum techniques. F Roseburg, Addison- WesIey Pub1 Co, Znc, USA, 1965, 597 pages, $17.50. 33 : 37 1488. High vacuum electron beam furnace for the production of very pure metals. (Germany)
A high vacuum compartmented furnace and purification of all types of metals, continuous manner, without damage to electron-beam generator. C D Hunt, German Patent 1,204,415 USA Appl30
Mar 1962,
design permits the melting from Cu to Hf or W in a the heat-source, which is an (Cl
C22b),
4 Nov
1965,
16pages.
33 1489. Apparatus for electron-beam vacuum vaporization of wide metal
strips. The transverse electron guns are separated by comb-like projections of the pole plates. W C Heraeus, German Patent 1,206,260 (Cl C23c), 2 Dee 1965, Appl II Dee German).
1962,
4 pages,
Add to German
1490. A low energy nitrogen ion beam.
Patent
I,I99,097,
33 1492. Ion density in electron beams. (Netherlands) The charge trapped in electron or ion beams at pressures below breakdown may be determined from a genera1 integro-differential equation. An approximation method to solve the latter is given. D K Callebaut, Physica, 31 (8), 1965, 1177-1192. 33 1493. The effects of ion bombardment on molybdenite. (Japan) The effects of ion bombardment on MO& were studied by means of
transmission electron microscope. The bombardment is carried out by air or argon ions of 7 kV. K Mihama, Jap J Appl Phys, 5, March 1966, 202-207. 33 1494. An electron bombardment evaporation source for Ni-Fe alloys. (Germany)
Apparatus for evaporation of Fe-Ni alloy films is described in detail. A ceramic tile is heated in a MO container to melt the alloy using electron bombardment heating. A magnetic field alters the composition and the radial thickness distribution of the evaporated film. J C Brice and U Pick, Schleif-u Poliertechnik, 11, 1965, 351, (in German). 33 1495. Measurement of cathode temperature by the retarding-potential method. (USSR) The measurement of indirectly-heated oxide-cathode temperatures in
industrial valves by the retarding-potential method is described. The retarding-potential method is based on Schottky’s law and is capable of giving the temperature of the oxide surface to an accuracy of 0.5 per cent. The temperature drop across the oxide layer was determined for typical cases by this method; for a layer 50 p thick the drop was 20°C. The method is readily applicable to ordinary commercial valves (especially triodes) and is of particular importance in determining the causes of failure and in estimating changes in emission during the life of the valve. 0 M Nilov, Collection “Electronic Equipment” (Elektron pribostroenie),
Moscow-Leningrad,
“Energiya”,
1965,
1 O-16, (in Russian). 33 1496. Initial stage in the heating of exploding wires. (USSR)
The electron emission of tungsten wires constituting the filaments of vacuum diodes was studied when the wires were heated and finally exploded by high-density current pulses. Even when the voltage drop in the diode was several times less than the ionisation potential of tungsten vapour, there was an anomalously large anode current (higher than the characteristic Langmuir value). The anomalous rise in the anode current began when the temperature of the tungsten was substantially below its melting point. The additional emission was apparently due to an abnormal state of the metal surface; the main bulk of the metal remained in the normal state. S V Lebedev, Zh Eksper Teor Fiz, 50, 1966, 3, (in Russian). 33 1497. Depths of low-energy ion-bombardment damage in germanium.
(USA) R J MacDonald and D Haneman, J AppI Phys, 37, 1966,1609-1613. 33
: 45
Tungsten-barium cathode hermetization by electron-beam welding. (USSR) Normally produced tungsten-barium cathodes have a short life. In this paper a device for electron-beam welding of W-BaCO, cathodes is described. By this method prepared cathodes are hermetized and stable and different cathode geometries (eg rings) are possible. 1498.
G N Zinchenko, et al, Prib 209-210, (in Russian).
(in
Tekh Eksper,
I1 (I),
Jan-Feb
(USSR) 1966, 33
: 37
Some notes on ultrasoft X-ray fluorescence analysis, 10 to lOOAregion. (USA) Methods and instrumentation were developed to extend the range of X-ray fluorescence analysis to the light metals magnesium through beryllium. Current values for the minimum detectable limits for these elements and the associated instrumentation parameters are presented. Specific procedures are described for the use of an ultrasoft X-ray vacuum spectrograph. The development of large d-spacing multilayer analyzers and the construction of thin window systems are also covered. B L Henke, Advances in X-ray Analysis, 8, 1965, 269-284. 1499.
33 (Canada)
Apparatus has been constructed for the production of a nitrogen ion beam N,+ within the energy ranges S-30 eV. R H Prince, Toronto University, Ontario, Canada, May 1965, 70 pages. 33 1491. An electron beam technique for visualization of charge distribution. (Japan) H Saito, Jap J Appl Phys, 4 (II), Nov 1965, 886-895.
467
abstracts
1483-1499
In the apparatus described, the tungsten cathode is heated by the electron beam. Particulars are given of the electrodes used and of the beam currents and current densities obtainable with an emission surface temperature of 2900°K. An ion-separating electron gun is used which can be attached to the welding chamber at any angle. Examples of the various welds that can be produced are illustrated and discussed. Optical viewing of the welding operation is possible. E B Bas et al, Schweiz Arch, 31 (2), 1965, 40-49. 33 : 37 1483. Electron beam in modem vacuum metallurgy. (USSR) B E Paton and B A Movchan, Vest An SSR, 34 (I), 1965, 25-29, (in Russian). 33
1484. Low temperature Physics. J G Daunt. et al. (Editors). Proceed&s on Low Temper&re Phy&s, Columbus, Plenum Press, New York, 1965.
9th International Conference Ohio, 1964, Published by 33
1485. Description of invention 171471. Cathode of electrovacuum apparatus. (USSR) A new “sandwich” cathode for electronic vacuum systems is described. This comprises a metal base covered with a dielectric film, above which a thin conducting layer is deposited. The thickness of the conducting film is so chosen to allow electrons to pass through it from the dielectric. The conducting film is held at a negative potential with respect to the metal base. This cathode gives a high current density suitable for beam-type systems operating at UHF; the noise level is low and the lifetime substantial. A typical example uses an aluminium base, bearing its normal oxide film, with another metal deposited on top of this. V V Shcherbakov, Class Zld, 1304, MPK H 01 j, (in Russian). 33 1486. Description of invention 168371. Field-emission photocathode. (USSR)
A new photocathode composed of a germanium-nickel alloy and operating on the basis of field-emission photoconductivity is described. In this the distribution of the field between cathode and vacuum gap is affected by incoming light. Features of this photocathode include a spectral characteristic extending to 3.3 p, high sensitivity, and a non-linear lux/ampere characteristic, enabling the cathode to be used under very strong illumination. The cathode is made in the form of a sharp point in order to create a strong electric field; it operates stably and for long periods at a pressure of lo+’ torr. P G Borzyak, et al, Class 2ld, 29a0, MPK H 01 I, (in Russian). 33
1487. Handbook for electron tube and vacuum techniques. F Roseburg, Addison- WesIey Pub1 Co, Znc, USA, 1965, 597 pages, $17.50. 33 : 37 1488. High vacuum electron beam furnace for the production of very pure metals. (Germany)
A high vacuum compartmented furnace and purification of all types of metals, continuous manner, without damage to electron-beam generator. C D Hunt, German Patent 1,204,415 USA Appl30
Mar 1962,
design permits the melting from Cu to Hf or W in a the heat-source, which is an (Cl
C22b),
4 Nov
1965,
16pages.
33 1489. Apparatus for electron-beam vacuum vaporization of wide metal
strips. The transverse electron guns are separated by comb-like projections of the pole plates. W C Heraeus, German Patent 1,206,260 (Cl C23c), 2 Dee 1965, Appl II Dee German).
1962,
4 pages,
Add to German
1490. A low energy nitrogen ion beam.
Patent
I,I99,097,
33 1492. Ion density in electron beams. (Netherlands) The charge trapped in electron or ion beams at pressures below breakdown may be determined from a genera1 integro-differential equation. An approximation method to solve the latter is given. D K Callebaut, Physica, 31 (8), 1965, 1177-1192. 33 1493. The effects of ion bombardment on molybdenite. (Japan) The effects of ion bombardment on MO& were studied by means of
transmission electron microscope. The bombardment is carried out by air or argon ions of 7 kV. K Mihama, Jap J Appl Phys, 5, March 1966, 202-207. 33 1494. An electron bombardment evaporation source for Ni-Fe alloys. (Germany)
Apparatus for evaporation of Fe-Ni alloy films is described in detail. A ceramic tile is heated in a MO container to melt the alloy using electron bombardment heating. A magnetic field alters the composition and the radial thickness distribution of the evaporated film. J C Brice and U Pick, Schleif-u Poliertechnik, 11, 1965, 351, (in German). 33 1495. Measurement of cathode temperature by the retarding-potential method. (USSR) The measurement of indirectly-heated oxide-cathode temperatures in
industrial valves by the retarding-potential method is described. The retarding-potential method is based on Schottky’s law and is capable of giving the temperature of the oxide surface to an accuracy of 0.5 per cent. The temperature drop across the oxide layer was determined for typical cases by this method; for a layer 50 p thick the drop was 20°C. The method is readily applicable to ordinary commercial valves (especially triodes) and is of particular importance in determining the causes of failure and in estimating changes in emission during the life of the valve. 0 M Nilov, Collection “Electronic Equipment” (Elektron pribostroenie),
Moscow-Leningrad,
“Energiya”,
1965,
1 O-16, (in Russian). 33 1496. Initial stage in the heating of exploding wires. (USSR)
The electron emission of tungsten wires constituting the filaments of vacuum diodes was studied when the wires were heated and finally exploded by high-density current pulses. Even when the voltage drop in the diode was several times less than the ionisation potential of tungsten vapour, there was an anomalously large anode current (higher than the characteristic Langmuir value). The anomalous rise in the anode current began when the temperature of the tungsten was substantially below its melting point. The additional emission was apparently due to an abnormal state of the metal surface; the main bulk of the metal remained in the normal state. S V Lebedev, Zh Eksper Teor Fiz, 50, 1966, 3, (in Russian). 33 1497. Depths of low-energy ion-bombardment damage in germanium.
(USA) R J MacDonald and D Haneman, J AppI Phys, 37, 1966,1609-1613. 33
: 45
Tungsten-barium cathode hermetization by electron-beam welding. (USSR) Normally produced tungsten-barium cathodes have a short life. In this paper a device for electron-beam welding of W-BaCO, cathodes is described. By this method prepared cathodes are hermetized and stable and different cathode geometries (eg rings) are possible. 1498.
G N Zinchenko, et al, Prib 209-210, (in Russian).
(in
Tekh Eksper,
I1 (I),
Jan-Feb
(USSR) 1966, 33
: 37
Some notes on ultrasoft X-ray fluorescence analysis, 10 to lOOAregion. (USA) Methods and instrumentation were developed to extend the range of X-ray fluorescence analysis to the light metals magnesium through beryllium. Current values for the minimum detectable limits for these elements and the associated instrumentation parameters are presented. Specific procedures are described for the use of an ultrasoft X-ray vacuum spectrograph. The development of large d-spacing multilayer analyzers and the construction of thin window systems are also covered. B L Henke, Advances in X-ray Analysis, 8, 1965, 269-284. 1499.
33 (Canada)
Apparatus has been constructed for the production of a nitrogen ion beam N,+ within the energy ranges S-30 eV. R H Prince, Toronto University, Ontario, Canada, May 1965, 70 pages. 33 1491. An electron beam technique for visualization of charge distribution. (Japan) H Saito, Jap J Appl Phys, 4 (II), Nov 1965, 886-895.
467