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1862. Thin film capacitors
Classified abstracts 1852-1882 physical and electrical properties of the deposited material. Particular investigations determined: dielectric constant; loss factor; voltage breakdown strength; surface properties using the MOS technique; and material properties by monitoring infrared absorption, chemical etch rate and film growth rate. R C G Swann et al, J Electrochem Sot, 114 (i’), July 1967, 714-717. 30 1852. Sputtering.
(USA) Alloy targets were sputtered to determine the amount of sputtering required to reach equilibrium conditions, where material is removed in the same proportions as the bulk. In alloys of 55 per cent Cu and 45 per cent Ni and of 90 per cent Ni and 10 per cent Ti, it appears that an equivalent of 10-20 atomic layers must be removed before equilibrium conditions are reached at bombarding ion energies of 500-1000 eV. Experiments with simultaneous sputtering of two targets having widely different yields are discussed. G S Anderson et al, Rep AD-643920, 1966 (L&on Systems Inc, Minneapolis,
Minnesota).
1853. Sputtering intermediates on titanium electrodeposited chromium. (USA)
to improve
adhesion
30 of
Intermediate layers of chromium, nickel and/or iron have been sputtered on titanium substrates. In the latter cases, upon subsequent chromium electrodeposition, adhesion was localized and nonuniform. Chromium electrodeposits on chromium intermediate-sputtered layers, however, were uniform and adherent as indicated by bend tests. F X Hassion, chusetts).
Rep SA-TR18-1097,
1966 (Springfield
Armory,
30
films by cathodic sputtering. (USA) For values of x varying from 0.05 to 0.15, these films were sputtered on to single crystal substrates of sodium chloride, germanium and sapphire. The resultant films were amorphous but became crystalline on annealing. Optical transmission and electron probe analysis showed a slightly lower mercury concentration in the film than in the source material. Although cadmium telluride sputtered films are possible in polycrystalline form, it was not found possible to obtain films of sputtered mercury telluride. The vacuum chamber used was evacuated to 1OW torr and back-filled with oxygen-free argon. After several such cycles the system was evacuated to 10e6 torr and the pressure adjusted by increasing the argon pressure using a micrometer valve. The use of oxygen-free argon as discharge gas enhanced the disintegration rate of the source material and prevented undesirable reactions between the sputtered deposit and the residual gas. Sot, 114 (6), June 1967,616619.
1855. Tantalum oxide films prepared by oxygen plasma and reactive sputtering. (USA)
30 anodization
The processes of glow discharge anodization and dc diode reactive sputtering were investigated for the formation of tantalum oxide films for thin-film capacitors. The dc reactive sputtering was carried out at a cathode potential of 4 kV and in an argon pressure of 30 mtorr. At this potential, it was found that the deposition rate of tantalum oxide (in &min) could be expressed as : 6x 1O-3 divided by the oxygen partial pressure in the oxygen-argon gas mixture (for the pressure range of oxygen from 8 x 1O-6 to 1 x 1O-2 torr, and an electrode spacing 10 cm). The gas phase anodization was carried out at a cathode potential of 1 kV and a pressure of 50 mtorr of oxygen. For this purpose a tantalum film deposited by sputtering in pure argon was used. Dielectrics up to a maximum thickness of 3000 8, could be prepared by these methods. The first method (dc reactive sputtering) produces thickness variations over 50 cmB of 4 to 20 per cent compared with the second method (glow discharge) which gave variations of 4 to 1 per cent. F Vratny, J Am Ceram Sot, 50 (6), June 1967,283-287. 30 1856. On using the method of cathode sputtering for the preparation of semiconducting compound thin films. (Czechoslovakia)
Equipment is described for preparing TnSb thin films by cathode sputtering. The dependence between the film thickness and electrical characteristics on sputtering parameters is stated. Since, in a glow discharge, no decomposition into free components will take place, the suitability for preparing other compound thin films by this method is discussed. J Cervenak,
Slabopr
Obzor,
28 (7), July 1967, 442-447
barriers
made
by localized
(in Czech).
30 sputtering
A device is described for the fabrication of fast diodes. Si-Au potential barriers are produced by the following method: on a Si plate a layer of SiO, is produced and a metal foil mask with a hole is attached. Then SiO, is removed under argon at 1O-3 torr by ionic etching, localized to the holes at the mask, Subsequently the apparatus is evacuated and Au film is evaporated through the same mask. In this way, Si-Au contacts with diameters as small as 100 microns have been made. Z Majewski, Bull Acad Polon Sci Sir Sci Tech, 15 (4), 1967, 343-346 (in English). 30 1858. Vacuum processes for the deposition of thin films.
(Germany) The similarities and characteristic differences of evaporation and condensation processes in high vacuum evaporation, cathodic sputtering, and plasma sputtering are explained. Applications of these techniques and the associated vacuum systems are described. Cathodic sputtering is considered as most suitable for the deposition of “high-boiling” materials, at rates of up to 10 &sec on small surfaces. High vacuum evaporation can be used for the de osition of most elements and compounds, at rates of 10e-lo3 1 /sec. The applications of these techniques include a very large field from microcircuits to plating of plastics and metals. KG Gunther, Chem Zng Tech, 39 (ll), June 1967,641~648 (in German).
Massa-
1854. Cd,Hg,,Te
H Kraus et al, J Electrochem
1857. Silicon-gold potential method. (Poland)
1859. Process for the vapour deposition (USA) radiation of the substrate.
of material
30 without thermal
The process consists of separating the vapour waves coming from the vapour source from the accompanying heat waves, by decomposing both types of waves simultaneously into impulses of definite length. The more rapid and therefore preceding heat wave impulses are caught by a moving screen system, while the relatively slower vapour wave impulses are allowed to pass through unhindered. A F Horn and A F Aldrian, US Patent 3,333,982, Patent Ofice, 841 (l), 1st Aug 1967, 230.
Official Gaz US
30 (USA) 1860. Reduction of oxides by ion bombardment. The deposition of a metal coating on a surface of an oxide body, such as barium titanate, copper oxide, iron oxide, silicon oxide, tantalum oxide and titanium oxide, comprises mounting the oxide body and a piece of metal within the chamber. Argon, helium, krypton, mercury, neon or xenon can be fed into the chamber for ionisation. A radio frequency signal is applied to the oxide body for bombarding and selectively removing oxygen from the surface. The bombarded surface is then coated with particles from the metal. Litton O&e,
Systems Inc, US Patent 3,336,211, 841 (3), 15th Aug 1967, 921.
Oficial
Gaz
US Patent
30
1861. Metal-film production. (Great Britain) Suitable for producing a thin metallic film on a substrate by vacuum deposition, a number of substrates are caused to be tumbled together while being subjected to the metal vapour under the required conditions of heat and vacuum, the proximity of the source of metal vapour to the overall volumetric space occupied by the substrates while they are being tumbled being variable to permit control of this process. In a preferred procedure, the specified volumetric space is shielded from the metal-vapour source, and the vapour is only permitted to reach the space via a special access area of variable predeterminable dimensions. American Components Inc, Brit Patent 1,074,901, Patent Abstr, 7 (30) part 5, 28th July 1967. 30
(Great Britain) Capacitors having stable capacitance, low dissipation factors and stable temperature coefficient for use in microminiaturized circuits are made by building up alternate layers of metal and vapourdeposited void-free poly-p-xylylene film. Films of at least 100 8, may be deposited on gold, silver, copper, aluminium, lead or selenium foil or wire with a bulk resistivity less than 100 and preferably less than 10 pohm cm. The resulting capacitors are self-healing in that any electrical breakdown or arcing may be removed by burning through 1862. Thin film capacitors.
623
Classified abstracts
1863-1874
the metal layer at the point of breakdown with a current surge. (Author) Union Carbide Corp, Brif Patent 1,075,094, Patent Abstr, 7 (31) (part 6), 4th Aug 1967, 1. 31. EVACUATION AND SEALING 31 : 18 Porosity effects in the ionization of caesium on tungsten. See abstract number 1779. 31 : 18 Thermionic emitters consisting of BaO-UO, dispersed in a tungsten matrix. See abstract number 1791. 31 ~46 1863. Cryostat for magneto-optical investigations. (USSR) A design of a laboratory cryostat for investigations at liquid helium temperatures is described. A quartz window is sealed to metal walls by epoxy resin containing 66 per cent of ED-6 epoxy, 6 per cent of hexamethylenediamide and 28 per cent of Al powder. This resin is vacuum-tight and also usable for quick temperature changes from 300 to 4°K. V N Pavlov and V V Eremenko, Pribory Tekh Eksper, 12 (3), May-June 1967, 208-210 (in Russian). 31 1864. Physical chemistry of cleaning. (USA) The effects of contaminants on the properties of materials important to electronic devices and to related vacuum processes are discussed. Modern methods of testing and maintaining cleanliness are described. G L Krieger et al, Rep SC-TM-66-428 (Sandia Carp, Albuquerque, New Mexico). 31 1865. A glass/metal liquid helium Dewar. (USA) Helium Dewars are usually made either of glass or of metal, each with its merits and drawbacks. The Dewar described retains the merits of both types Dewars, the inside being made of glass and the outside of metal. The two parts are connected by an O-ring seal. C Bickart and C R Viswanathan, Cryogenic Technol, 3 (3), 1967,96-98. 31 1866. Electron discharge device having a vacuum sealing member and mechanical support means between the tube main body and the collector. (USA) This high frequency discharge device includes a beam forming and projecting means coupled at the upstream end and a metal beam collector member coupled to the body at the downstream end. It has an annular dielectric insulating member, vacuum sealed between the tube main body and metal beam collector, The tube forms a vacuum envelope in conjunction with the metal collector member, beam forming and projecting means. It is mechanically supported but insulated from the tube. Varian Associates, US Patent 3,336,491, Official Gaz USPatent Office, 841 (3), 15th Aug 1967, 988. 31 1867. Cryostat. (Germany) This has thermal vacuum insulation for operation with liquid coolants, such as liquid nitrogen, has a coolant container, an outer jacket and athermal shield consisting of two coaxial walls forming a vacuum tight space between container and jacket, whereby the latter has a cover in which are provided openings for insertion of coolant, removal of vapour and other purposes. A vacuum-tight connection is provided in each case between the upper edges of the container and the inner wall and the upper edges of the jacket and the outer wall. The two walls have a vacuum tight seal to each other only at their lower edges and form a jacketing space which is open towards the vapour chamber in the container and in which an insert of low thermal conductivity and fixed to the cover is arranged coaxially, whereby the the opening for vapour removal lies between this insert and the outer wall. (Author) V E Keijlin, German Patent 1,242,898, Patent Abstr, 7 (30) part D, 2nd Aug 1967, 3. 32. NUCLEONICS
32 : 20 Mechanical design of the baseball coil and plasma-trapping chamber. See abstract number 1797. 32 : 21 Liquid helium cryopumps for a large plasma research machine. See abstract number 1807. 624
32 : 18 1868. Plasma sources of ions of high-melting point materials. (USSR) Recent methods of producing a beam of high-melting point material ions by means of a discharge in the material vapours are summarized and compared. Typical designs of ion sources for electromagnetic isotope separators are discussed. M D Gabovich, Pribory Tekh Eksper, 12 (3), May-June 1967, 5-19 (in Russian). 32 1869. Deflection of an accelerated beam to the internal target in a
strong-focusing Synchrotron. (USSR) Equations are derived to illustrate a method of achieving an azimuthally symmetric local orbit perturbation with respect to the target. This method can be used to deflect the beam from the vacuum chamber in accelerators which use laminated electromagnets, when the perturbation increases quickly enough. I A Shukeilo, Elec Instr High-Energy Phys, (Collection of Papers), No 1, Rep AEC-TR-6636, Dee 1966, l-5 (Israel Programme for Scientific
Translations
Ltd, Jerusalem).
32 1870. Ion-optical system computation for direct action accelerators
taking into account space charge. (USSR) General relations between beam parameters at the entrance and exit of the accelerator tube are derived, and a method of computing optimum beam input parameters is given. Shaping of the charged particle beam at the entrance of the accelerator tube by electrostatic focusing systems is discussed. V S Kuznetzov, Elec Instr, High-Energy Phys, (Collection of Papers), No 1, Rep AEC-TR-6636, Dee 1966, 66-77 (Israel Programme for Scientific
Translations
Ltd, Jerusalem). 32
1871. A high-current pulsed ion course.
(USSR) The ion source and measurement apparatus are described; experimental procedures and results are discussed. Emphasis in the description is placed on the selection system and the displacement of the plasma emission opening in the region of maximum intensity of the magnetic field. It was found that: (1) the cover plate-extracting electrode with grid selection system affords stable ion beams with currents up to 1.5 A ; (2) it is possible to obtain focused ion beams of 70 KeV; (3) further increase of the ion current is possible through increase of the size of the source and a corresponding increase of the operational parameters. The most promising means of obtaining both pulsed and continuous ion beams with a current considerably in excess of 1 A is by using multijet plasma sources which create a large, dense plasma surface in the selection region. M A Abroyan and V L Komarov, Elec Instr High-Energy Phys (Collection ofPapers), No 1, Rep AEC-TR-6636,97-109 (Israel Programme for Scientific
Translations
Ltd, Jerusalem). 32
: 33
1872. A high voltage trielectrode electron gun.
(USSR) The effect on beam focusing and other gun parameters of a cathode placed along the axis of an electron gun with Pierce optics, and a tri-electrode electron gun design based on the Pierce gun are discussed. A description is given of the tri-electrode gun, for pulsed operation at 80 kV with beam currents of up to 5A, in which it is possible to alter the beam current without affecting the angle of divergence and beam energy. The gun is completely demountable. K P Rybas and A T Ermolaev, Elec Znstr High-Energy Phys, (Collection of Papers), No 1, Rep AEC-TR-6636, Dee 1966, 110-l 17 (Israel Programme for Scientific
Translations
Ltd, Jerusalem).
32 1873. A high frequency ion source for direct action accelerators.
(USSR) An ion source design for electrostatic and neutron generators is described which provides compactness, simplicity and reliability of construction, low supply power and small gas discharge. The source was checked in a scale model of a 2 MeV electrostatic generator. L I Ivanova and A I Solnyshkov, Elec Znstr High-Energy Phys (Collection of Papers) No 1, 1966, Rep AEC-TR-6636, 118-122 (Israel Programme for Scientific Translations Ltd, Jerusalem). 32 1874. Vacuum chambers of strong-focusing synchrotrons.
(USSR) The requirements and designs for accelerator vacuum chambers are reviewed. The chamber material and thickness, the effects of pressure difference on inside and outside of walls, and the effects of particle bombardment are considered. Details are presented on chamber
(USA) Alloy targets were sputtered to determine the amount of sputtering required to reach equilibrium conditions, where material is removed in the same proportions as the bulk. In alloys of 55 per cent Cu and 45 per cent Ni and of 90 per cent Ni and 10 per cent Ti, it appears that an equivalent of 10-20 atomic layers must be removed before equilibrium conditions are reached at bombarding ion energies of 500-1000 eV. Experiments with simultaneous sputtering of two targets having widely different yields are discussed. G S Anderson et al, Rep AD-643920, 1966 (L&on Systems Inc, Minneapolis,
Minnesota).
1853. Sputtering intermediates on titanium electrodeposited chromium. (USA)
to improve
adhesion
30 of
Intermediate layers of chromium, nickel and/or iron have been sputtered on titanium substrates. In the latter cases, upon subsequent chromium electrodeposition, adhesion was localized and nonuniform. Chromium electrodeposits on chromium intermediate-sputtered layers, however, were uniform and adherent as indicated by bend tests. F X Hassion, chusetts).
Rep SA-TR18-1097,
1966 (Springfield
Armory,
30
films by cathodic sputtering. (USA) For values of x varying from 0.05 to 0.15, these films were sputtered on to single crystal substrates of sodium chloride, germanium and sapphire. The resultant films were amorphous but became crystalline on annealing. Optical transmission and electron probe analysis showed a slightly lower mercury concentration in the film than in the source material. Although cadmium telluride sputtered films are possible in polycrystalline form, it was not found possible to obtain films of sputtered mercury telluride. The vacuum chamber used was evacuated to 1OW torr and back-filled with oxygen-free argon. After several such cycles the system was evacuated to 10e6 torr and the pressure adjusted by increasing the argon pressure using a micrometer valve. The use of oxygen-free argon as discharge gas enhanced the disintegration rate of the source material and prevented undesirable reactions between the sputtered deposit and the residual gas. Sot, 114 (6), June 1967,616619.
1855. Tantalum oxide films prepared by oxygen plasma and reactive sputtering. (USA)
30 anodization
The processes of glow discharge anodization and dc diode reactive sputtering were investigated for the formation of tantalum oxide films for thin-film capacitors. The dc reactive sputtering was carried out at a cathode potential of 4 kV and in an argon pressure of 30 mtorr. At this potential, it was found that the deposition rate of tantalum oxide (in &min) could be expressed as : 6x 1O-3 divided by the oxygen partial pressure in the oxygen-argon gas mixture (for the pressure range of oxygen from 8 x 1O-6 to 1 x 1O-2 torr, and an electrode spacing 10 cm). The gas phase anodization was carried out at a cathode potential of 1 kV and a pressure of 50 mtorr of oxygen. For this purpose a tantalum film deposited by sputtering in pure argon was used. Dielectrics up to a maximum thickness of 3000 8, could be prepared by these methods. The first method (dc reactive sputtering) produces thickness variations over 50 cmB of 4 to 20 per cent compared with the second method (glow discharge) which gave variations of 4 to 1 per cent. F Vratny, J Am Ceram Sot, 50 (6), June 1967,283-287. 30 1856. On using the method of cathode sputtering for the preparation of semiconducting compound thin films. (Czechoslovakia)
Equipment is described for preparing TnSb thin films by cathode sputtering. The dependence between the film thickness and electrical characteristics on sputtering parameters is stated. Since, in a glow discharge, no decomposition into free components will take place, the suitability for preparing other compound thin films by this method is discussed. J Cervenak,
Slabopr
Obzor,
28 (7), July 1967, 442-447
barriers
made
by localized
(in Czech).
30 sputtering
A device is described for the fabrication of fast diodes. Si-Au potential barriers are produced by the following method: on a Si plate a layer of SiO, is produced and a metal foil mask with a hole is attached. Then SiO, is removed under argon at 1O-3 torr by ionic etching, localized to the holes at the mask, Subsequently the apparatus is evacuated and Au film is evaporated through the same mask. In this way, Si-Au contacts with diameters as small as 100 microns have been made. Z Majewski, Bull Acad Polon Sci Sir Sci Tech, 15 (4), 1967, 343-346 (in English). 30 1858. Vacuum processes for the deposition of thin films.
(Germany) The similarities and characteristic differences of evaporation and condensation processes in high vacuum evaporation, cathodic sputtering, and plasma sputtering are explained. Applications of these techniques and the associated vacuum systems are described. Cathodic sputtering is considered as most suitable for the deposition of “high-boiling” materials, at rates of up to 10 &sec on small surfaces. High vacuum evaporation can be used for the de osition of most elements and compounds, at rates of 10e-lo3 1 /sec. The applications of these techniques include a very large field from microcircuits to plating of plastics and metals. KG Gunther, Chem Zng Tech, 39 (ll), June 1967,641~648 (in German).
Massa-
1854. Cd,Hg,,Te
H Kraus et al, J Electrochem
1857. Silicon-gold potential method. (Poland)
1859. Process for the vapour deposition (USA) radiation of the substrate.
of material
30 without thermal
The process consists of separating the vapour waves coming from the vapour source from the accompanying heat waves, by decomposing both types of waves simultaneously into impulses of definite length. The more rapid and therefore preceding heat wave impulses are caught by a moving screen system, while the relatively slower vapour wave impulses are allowed to pass through unhindered. A F Horn and A F Aldrian, US Patent 3,333,982, Patent Ofice, 841 (l), 1st Aug 1967, 230.
Official Gaz US
30 (USA) 1860. Reduction of oxides by ion bombardment. The deposition of a metal coating on a surface of an oxide body, such as barium titanate, copper oxide, iron oxide, silicon oxide, tantalum oxide and titanium oxide, comprises mounting the oxide body and a piece of metal within the chamber. Argon, helium, krypton, mercury, neon or xenon can be fed into the chamber for ionisation. A radio frequency signal is applied to the oxide body for bombarding and selectively removing oxygen from the surface. The bombarded surface is then coated with particles from the metal. Litton O&e,
Systems Inc, US Patent 3,336,211, 841 (3), 15th Aug 1967, 921.
Oficial
Gaz
US Patent
30
1861. Metal-film production. (Great Britain) Suitable for producing a thin metallic film on a substrate by vacuum deposition, a number of substrates are caused to be tumbled together while being subjected to the metal vapour under the required conditions of heat and vacuum, the proximity of the source of metal vapour to the overall volumetric space occupied by the substrates while they are being tumbled being variable to permit control of this process. In a preferred procedure, the specified volumetric space is shielded from the metal-vapour source, and the vapour is only permitted to reach the space via a special access area of variable predeterminable dimensions. American Components Inc, Brit Patent 1,074,901, Patent Abstr, 7 (30) part 5, 28th July 1967. 30
(Great Britain) Capacitors having stable capacitance, low dissipation factors and stable temperature coefficient for use in microminiaturized circuits are made by building up alternate layers of metal and vapourdeposited void-free poly-p-xylylene film. Films of at least 100 8, may be deposited on gold, silver, copper, aluminium, lead or selenium foil or wire with a bulk resistivity less than 100 and preferably less than 10 pohm cm. The resulting capacitors are self-healing in that any electrical breakdown or arcing may be removed by burning through 1862. Thin film capacitors.
623
Classified abstracts
1863-1874
the metal layer at the point of breakdown with a current surge. (Author) Union Carbide Corp, Brif Patent 1,075,094, Patent Abstr, 7 (31) (part 6), 4th Aug 1967, 1. 31. EVACUATION AND SEALING 31 : 18 Porosity effects in the ionization of caesium on tungsten. See abstract number 1779. 31 : 18 Thermionic emitters consisting of BaO-UO, dispersed in a tungsten matrix. See abstract number 1791. 31 ~46 1863. Cryostat for magneto-optical investigations. (USSR) A design of a laboratory cryostat for investigations at liquid helium temperatures is described. A quartz window is sealed to metal walls by epoxy resin containing 66 per cent of ED-6 epoxy, 6 per cent of hexamethylenediamide and 28 per cent of Al powder. This resin is vacuum-tight and also usable for quick temperature changes from 300 to 4°K. V N Pavlov and V V Eremenko, Pribory Tekh Eksper, 12 (3), May-June 1967, 208-210 (in Russian). 31 1864. Physical chemistry of cleaning. (USA) The effects of contaminants on the properties of materials important to electronic devices and to related vacuum processes are discussed. Modern methods of testing and maintaining cleanliness are described. G L Krieger et al, Rep SC-TM-66-428 (Sandia Carp, Albuquerque, New Mexico). 31 1865. A glass/metal liquid helium Dewar. (USA) Helium Dewars are usually made either of glass or of metal, each with its merits and drawbacks. The Dewar described retains the merits of both types Dewars, the inside being made of glass and the outside of metal. The two parts are connected by an O-ring seal. C Bickart and C R Viswanathan, Cryogenic Technol, 3 (3), 1967,96-98. 31 1866. Electron discharge device having a vacuum sealing member and mechanical support means between the tube main body and the collector. (USA) This high frequency discharge device includes a beam forming and projecting means coupled at the upstream end and a metal beam collector member coupled to the body at the downstream end. It has an annular dielectric insulating member, vacuum sealed between the tube main body and metal beam collector, The tube forms a vacuum envelope in conjunction with the metal collector member, beam forming and projecting means. It is mechanically supported but insulated from the tube. Varian Associates, US Patent 3,336,491, Official Gaz USPatent Office, 841 (3), 15th Aug 1967, 988. 31 1867. Cryostat. (Germany) This has thermal vacuum insulation for operation with liquid coolants, such as liquid nitrogen, has a coolant container, an outer jacket and athermal shield consisting of two coaxial walls forming a vacuum tight space between container and jacket, whereby the latter has a cover in which are provided openings for insertion of coolant, removal of vapour and other purposes. A vacuum-tight connection is provided in each case between the upper edges of the container and the inner wall and the upper edges of the jacket and the outer wall. The two walls have a vacuum tight seal to each other only at their lower edges and form a jacketing space which is open towards the vapour chamber in the container and in which an insert of low thermal conductivity and fixed to the cover is arranged coaxially, whereby the the opening for vapour removal lies between this insert and the outer wall. (Author) V E Keijlin, German Patent 1,242,898, Patent Abstr, 7 (30) part D, 2nd Aug 1967, 3. 32. NUCLEONICS
32 : 20 Mechanical design of the baseball coil and plasma-trapping chamber. See abstract number 1797. 32 : 21 Liquid helium cryopumps for a large plasma research machine. See abstract number 1807. 624
32 : 18 1868. Plasma sources of ions of high-melting point materials. (USSR) Recent methods of producing a beam of high-melting point material ions by means of a discharge in the material vapours are summarized and compared. Typical designs of ion sources for electromagnetic isotope separators are discussed. M D Gabovich, Pribory Tekh Eksper, 12 (3), May-June 1967, 5-19 (in Russian). 32 1869. Deflection of an accelerated beam to the internal target in a
strong-focusing Synchrotron. (USSR) Equations are derived to illustrate a method of achieving an azimuthally symmetric local orbit perturbation with respect to the target. This method can be used to deflect the beam from the vacuum chamber in accelerators which use laminated electromagnets, when the perturbation increases quickly enough. I A Shukeilo, Elec Instr High-Energy Phys, (Collection of Papers), No 1, Rep AEC-TR-6636, Dee 1966, l-5 (Israel Programme for Scientific
Translations
Ltd, Jerusalem).
32 1870. Ion-optical system computation for direct action accelerators
taking into account space charge. (USSR) General relations between beam parameters at the entrance and exit of the accelerator tube are derived, and a method of computing optimum beam input parameters is given. Shaping of the charged particle beam at the entrance of the accelerator tube by electrostatic focusing systems is discussed. V S Kuznetzov, Elec Instr, High-Energy Phys, (Collection of Papers), No 1, Rep AEC-TR-6636, Dee 1966, 66-77 (Israel Programme for Scientific
Translations
Ltd, Jerusalem). 32
1871. A high-current pulsed ion course.
(USSR) The ion source and measurement apparatus are described; experimental procedures and results are discussed. Emphasis in the description is placed on the selection system and the displacement of the plasma emission opening in the region of maximum intensity of the magnetic field. It was found that: (1) the cover plate-extracting electrode with grid selection system affords stable ion beams with currents up to 1.5 A ; (2) it is possible to obtain focused ion beams of 70 KeV; (3) further increase of the ion current is possible through increase of the size of the source and a corresponding increase of the operational parameters. The most promising means of obtaining both pulsed and continuous ion beams with a current considerably in excess of 1 A is by using multijet plasma sources which create a large, dense plasma surface in the selection region. M A Abroyan and V L Komarov, Elec Instr High-Energy Phys (Collection ofPapers), No 1, Rep AEC-TR-6636,97-109 (Israel Programme for Scientific
Translations
Ltd, Jerusalem). 32
: 33
1872. A high voltage trielectrode electron gun.
(USSR) The effect on beam focusing and other gun parameters of a cathode placed along the axis of an electron gun with Pierce optics, and a tri-electrode electron gun design based on the Pierce gun are discussed. A description is given of the tri-electrode gun, for pulsed operation at 80 kV with beam currents of up to 5A, in which it is possible to alter the beam current without affecting the angle of divergence and beam energy. The gun is completely demountable. K P Rybas and A T Ermolaev, Elec Znstr High-Energy Phys, (Collection of Papers), No 1, Rep AEC-TR-6636, Dee 1966, 110-l 17 (Israel Programme for Scientific
Translations
Ltd, Jerusalem).
32 1873. A high frequency ion source for direct action accelerators.
(USSR) An ion source design for electrostatic and neutron generators is described which provides compactness, simplicity and reliability of construction, low supply power and small gas discharge. The source was checked in a scale model of a 2 MeV electrostatic generator. L I Ivanova and A I Solnyshkov, Elec Znstr High-Energy Phys (Collection of Papers) No 1, 1966, Rep AEC-TR-6636, 118-122 (Israel Programme for Scientific Translations Ltd, Jerusalem). 32 1874. Vacuum chambers of strong-focusing synchrotrons.
(USSR) The requirements and designs for accelerator vacuum chambers are reviewed. The chamber material and thickness, the effects of pressure difference on inside and outside of walls, and the effects of particle bombardment are considered. Details are presented on chamber