- Email: [email protected]
1911. Surface cleaning techniques in ultrahigh vacuum
Classified
abstracts
1905-1917 33 :20
1905. Primary ionization coefficient of deuterium.
(Great Britain) Ionization currents in purilied deuterium between plane parallel gold electrodes at separations up to 1.2 cm have been measured in the range 47
J Appl Phys, 18 (7), July 1967, 939-943.
33 1906. Low energy high perveance electron gun. (Italy) A low energy electron gun with good focusing properties has been developed. I‘he gun can work in the followmg conditions: energy of the electrons at the target, 80 eV ; cross section of the beam 1 mm”, and current density of the beam, 2 mA/cm2. The device consists of a Pierce-type gun and a decelerating and focusing structure. A description of the techniques employed in the construction is given. G liressanin and G Hodapp, Rep EUR-3255 1966 (European Atomic Energy
Community,
Ispra, Italy). 33
1907. A new mass spectrometer
without magnetic field. (Germany) A mass spectrometer is described, in which a partially homogeneous rf field operates perpendicular to the entrance direction of the ions. The rf voltage is rectangular. Ions, which contribute to the signal, pass the analyzer in about a period of the rf field and leave it parallel to the entrance direction. A small analyzer, applicable to vacuum measurements has been constructed. H Elschner, Angew Phys, 23 (2), July 1967, 77-81. 33 1908. Electron microscope. (Great Britain) This incorporates an image pick-up system, an electron gun for projecting a beam of electrons onto a specimen, an electron lens and the electron pick-up system. This last system employs a target which receives the electrons from the specimen to form an electron image, the target being of a material which exhibits electron bombardment induced conductivity. The target is scanned by an electron beam from a second electron gun on the side opposite to the first mentioned gun, to produce signals corresponding to the electron image on the target. The second electron gun has an anode aperture plate heated by an auxiliary heater to reduce contamination of the aperture. (Author) K K Hitachi Seisakusho, &it Patent 1,076,331, Patent Abstr, 7 (32) part D, 11th Aug 1967, 5. 33 1909. Electron-probe, X-ray microanalyser. (Germany) For additional determination of the crystalline structure of the part of the sample being examined, the device has an X-ray emitting target foil situated in the path of an electron gun. The foil is in the analyser vacuum chamber and is located at the focal point of the electron beam which is focussed by an electron lens system. The foil can be moved into and out of the beam path from outside the vacuum chamber, whilst a diaphragm between foil and sample focuses the X-rays and a withdrawable X-ray sensitive film or plate receives the X-rays reflected by the sample. (Author) T Ichinokawa, German Patent 1,243,899, Patent Abstr, 7 (32) part D, 16th Aug 1967, 5. 34. HIGH ALTITUDE AND SPACE TECHNOLOGY 34 : 33 Molecular beams and surface interactions. See abstract number 1897. 34 : 37 Apparatus to measure mid-infrared spectral emittance of cold powders in a vacuum. See abstract number 1912. 36. DRYING, DEGASSING AND CONCENTRATION 1910. Drying chamber for photographic materials. (Czechoslovakia) A drying chamber, type BP 4133, for the drying of photographic plates is described. This chamber is produced by Tesla Bmo, Czechoslovakia as a sub-assembly for electron microscope BS 413. The chamber is pumped by a mechanical pump and water vapour is adsorbed by P,O,. Anon, Jemna Mach Opt, 12 (7), July 1967, 204, (in Czech).
37. METALLURGY, INORGANIC CHEMISTRY, ANALYTICAL CIiEMISlRY 37 : 28 Measurement of remelt furnace pour temperatures by infrared pyrometry. See abstract number 1833. 37 : 33 Two crystal, vacuUm monochromator. See abstract number 1884. 37 1911. Surface cleaning techniques in ultrahigh vacuum. (USA) The results of a study to experimentally investigate vacuum methods for obtaming clean surfaces and for measurmg surface cleanliness are presented. Ion bombardment and abrasion with a rotating wire brush were used for obtaining clean surfaces and measurement of the work function was used to indicate surface cleanliness. F J Brock, Rep NASA-Ck-66213, 1966 (National Research Corp, Cambridge,
Massachusetts).
37 : 34 1912. Apparatus to measure mid-infrared spectral emittance of cold
powders in a vacuum. (USA) An apparatus used to measure the 8-13 micron emittance of silicate powders under simulated lunar conditions, is described. The device is enclosed in a stainless steel vacuum chamber, evacuated to 1O-5-1O-6 torr. The sample was contained in the removable lid of a constant temperature bath and its upper surface allowed to radiate into a cavity maintained at liquid nitrogen temperature. A F H Goetz and C A Bauman, Rev Sci Instrum, 38 (6), 1967,775-778. 37 1913. Deposition of carbon on diamond seed crystals. (USA) Experiments were performed to establish the feasibility of growing diamond crystals for electronic applications by the deposition of carbon on diamond seed crystals at moderate pressures. Methane at 1050°C and 1 torr was used as the source of carbon. Weight increases were consistently observed when pure methane was used. When the methane was diluted with either hydrogen or helium, the seed crystals decreased in weight. J C Angus and H Will, Rep AFCRL-66-686; AD-642786, 1966 (Case Inst of Technel, Cleveland, Ohio). 37 : 43 1914. The use of T P X plastic as shock tube window in the near ultraviolet. (Great Britain). Shock tube windows of TPX plastic are moulded by heating the powder under vacuum. The vacuum system used and the principal procedural steps are described. A A T Rees and G Roberts, J Sci Znstrum, 44 (7), 1967, 559. 37 1915. Apparatus for teeming degassed molten metal. (USA) The system includes a ladle with a pouring nozzle in the bottom wall with a stopper for controlling the flow. Respective load cells are held by a number of supports that are detachable. A refractory lined chamber is carried by these cells beneath the ladle and has a telescopic filling neck at the top. A flexible seal is provided between the nozzle and neck with a second nozzle for controlling the flow down from the chamber. The vacuum pump and drive are supported above the chamber. The ladle and apparatus can be moved freely about as a unit in all directions. H F Shekels, US Patent 3,333,626, Official Gaz US Patent Ofice, 841 (l), 1st Aug 1967, 128. 37 1916. Vacuum injection momding apparatus. (USA) The device consists of an evacuable filler which supplies casting material to a vacuum mould communicating with a primary supply vessel. An auxiliary vessel supplies casting material to the primary vessel, all being positioned for gravity flow. Evacuation of the vessels and filling means comprises an auxiliary primary evacuation line, which has a small conductance relative to the primary line with a valve in the auxiliary line. Another valve controls the flow of casting material and effects gas isolation between vessels. Leybold Holding A G, US Patent 3,335,462, Official Gaz US Patent Ofice, 841 (3), 15th Aug 1967, 703. 37 1917. Vacuum melting and casting furnace. (Great Britain) This comprises two chambers interconnected by a vacuum-tight door, and a crucible transferable from one chamber, in which the charge 627
abstracts
1905-1917 33 :20
1905. Primary ionization coefficient of deuterium.
(Great Britain) Ionization currents in purilied deuterium between plane parallel gold electrodes at separations up to 1.2 cm have been measured in the range 47
J Appl Phys, 18 (7), July 1967, 939-943.
33 1906. Low energy high perveance electron gun. (Italy) A low energy electron gun with good focusing properties has been developed. I‘he gun can work in the followmg conditions: energy of the electrons at the target, 80 eV ; cross section of the beam 1 mm”, and current density of the beam, 2 mA/cm2. The device consists of a Pierce-type gun and a decelerating and focusing structure. A description of the techniques employed in the construction is given. G liressanin and G Hodapp, Rep EUR-3255 1966 (European Atomic Energy
Community,
Ispra, Italy). 33
1907. A new mass spectrometer
without magnetic field. (Germany) A mass spectrometer is described, in which a partially homogeneous rf field operates perpendicular to the entrance direction of the ions. The rf voltage is rectangular. Ions, which contribute to the signal, pass the analyzer in about a period of the rf field and leave it parallel to the entrance direction. A small analyzer, applicable to vacuum measurements has been constructed. H Elschner, Angew Phys, 23 (2), July 1967, 77-81. 33 1908. Electron microscope. (Great Britain) This incorporates an image pick-up system, an electron gun for projecting a beam of electrons onto a specimen, an electron lens and the electron pick-up system. This last system employs a target which receives the electrons from the specimen to form an electron image, the target being of a material which exhibits electron bombardment induced conductivity. The target is scanned by an electron beam from a second electron gun on the side opposite to the first mentioned gun, to produce signals corresponding to the electron image on the target. The second electron gun has an anode aperture plate heated by an auxiliary heater to reduce contamination of the aperture. (Author) K K Hitachi Seisakusho, &it Patent 1,076,331, Patent Abstr, 7 (32) part D, 11th Aug 1967, 5. 33 1909. Electron-probe, X-ray microanalyser. (Germany) For additional determination of the crystalline structure of the part of the sample being examined, the device has an X-ray emitting target foil situated in the path of an electron gun. The foil is in the analyser vacuum chamber and is located at the focal point of the electron beam which is focussed by an electron lens system. The foil can be moved into and out of the beam path from outside the vacuum chamber, whilst a diaphragm between foil and sample focuses the X-rays and a withdrawable X-ray sensitive film or plate receives the X-rays reflected by the sample. (Author) T Ichinokawa, German Patent 1,243,899, Patent Abstr, 7 (32) part D, 16th Aug 1967, 5. 34. HIGH ALTITUDE AND SPACE TECHNOLOGY 34 : 33 Molecular beams and surface interactions. See abstract number 1897. 34 : 37 Apparatus to measure mid-infrared spectral emittance of cold powders in a vacuum. See abstract number 1912. 36. DRYING, DEGASSING AND CONCENTRATION 1910. Drying chamber for photographic materials. (Czechoslovakia) A drying chamber, type BP 4133, for the drying of photographic plates is described. This chamber is produced by Tesla Bmo, Czechoslovakia as a sub-assembly for electron microscope BS 413. The chamber is pumped by a mechanical pump and water vapour is adsorbed by P,O,. Anon, Jemna Mach Opt, 12 (7), July 1967, 204, (in Czech).
37. METALLURGY, INORGANIC CHEMISTRY, ANALYTICAL CIiEMISlRY 37 : 28 Measurement of remelt furnace pour temperatures by infrared pyrometry. See abstract number 1833. 37 : 33 Two crystal, vacuUm monochromator. See abstract number 1884. 37 1911. Surface cleaning techniques in ultrahigh vacuum. (USA) The results of a study to experimentally investigate vacuum methods for obtaming clean surfaces and for measurmg surface cleanliness are presented. Ion bombardment and abrasion with a rotating wire brush were used for obtaining clean surfaces and measurement of the work function was used to indicate surface cleanliness. F J Brock, Rep NASA-Ck-66213, 1966 (National Research Corp, Cambridge,
Massachusetts).
37 : 34 1912. Apparatus to measure mid-infrared spectral emittance of cold
powders in a vacuum. (USA) An apparatus used to measure the 8-13 micron emittance of silicate powders under simulated lunar conditions, is described. The device is enclosed in a stainless steel vacuum chamber, evacuated to 1O-5-1O-6 torr. The sample was contained in the removable lid of a constant temperature bath and its upper surface allowed to radiate into a cavity maintained at liquid nitrogen temperature. A F H Goetz and C A Bauman, Rev Sci Instrum, 38 (6), 1967,775-778. 37 1913. Deposition of carbon on diamond seed crystals. (USA) Experiments were performed to establish the feasibility of growing diamond crystals for electronic applications by the deposition of carbon on diamond seed crystals at moderate pressures. Methane at 1050°C and 1 torr was used as the source of carbon. Weight increases were consistently observed when pure methane was used. When the methane was diluted with either hydrogen or helium, the seed crystals decreased in weight. J C Angus and H Will, Rep AFCRL-66-686; AD-642786, 1966 (Case Inst of Technel, Cleveland, Ohio). 37 : 43 1914. The use of T P X plastic as shock tube window in the near ultraviolet. (Great Britain). Shock tube windows of TPX plastic are moulded by heating the powder under vacuum. The vacuum system used and the principal procedural steps are described. A A T Rees and G Roberts, J Sci Znstrum, 44 (7), 1967, 559. 37 1915. Apparatus for teeming degassed molten metal. (USA) The system includes a ladle with a pouring nozzle in the bottom wall with a stopper for controlling the flow. Respective load cells are held by a number of supports that are detachable. A refractory lined chamber is carried by these cells beneath the ladle and has a telescopic filling neck at the top. A flexible seal is provided between the nozzle and neck with a second nozzle for controlling the flow down from the chamber. The vacuum pump and drive are supported above the chamber. The ladle and apparatus can be moved freely about as a unit in all directions. H F Shekels, US Patent 3,333,626, Official Gaz US Patent Ofice, 841 (l), 1st Aug 1967, 128. 37 1916. Vacuum injection momding apparatus. (USA) The device consists of an evacuable filler which supplies casting material to a vacuum mould communicating with a primary supply vessel. An auxiliary vessel supplies casting material to the primary vessel, all being positioned for gravity flow. Evacuation of the vessels and filling means comprises an auxiliary primary evacuation line, which has a small conductance relative to the primary line with a valve in the auxiliary line. Another valve controls the flow of casting material and effects gas isolation between vessels. Leybold Holding A G, US Patent 3,335,462, Official Gaz US Patent Ofice, 841 (3), 15th Aug 1967, 703. 37 1917. Vacuum melting and casting furnace. (Great Britain) This comprises two chambers interconnected by a vacuum-tight door, and a crucible transferable from one chamber, in which the charge 627