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1699. Construction and operation of thin parallel plate proportional counters
Classified
abstracts
1690-1700 30 : 42
1690. The dielectric constant of zirconia.
(Great
Britain)
The value of the dielectric constant of zirconia, determined for the first time on single-crystals, is given as 22k3 and is almost independent of frequency from 100 c/s to 20 kc/s. This value is compared with the previous values obtained on films, which were in the range 12 to 25. P J Harrop and J N Wanklyn, 739-742.
Brif J Appl Phys,
18 (6), June 1967,
30 1691. Method and apparatus for cathode sputtering including suppressing temperature rise adjacent the anode using a localised magnetic fleld. (USA)
The apparatus positions the article in the sputter cathode and adjacent to the anode. A localized magnetic field is generated directly over the entire article surface and at right angles to the sputtering electric field. The article is cooled to enable the magnetic field strength to remain constant during the coating period. Charged particles are therefore deflected away from the article surface thus maintaining the article at a relatively low temperature. A rack and pinion is used to adjust the positional relationship in order to vary the cooling effect on the article. Int Business Mach Corp, US Patent 3,330,752, Ofice, 840 (2), 11th July 1967, 614.
Official Gaz US Patent
1692. Elongated electrode. (Germany) This has a core which is to be vaporized and a refractory shell, the core consisting of a mixture of platinum and carbon, and the refractory shell consisting of a material which does not evaporate in operation of the electrode to produce vapour from the core. In a vacuum deposition process, the electrode may be placed adjacent a second electrode, and an electric arc struck between the electrodes so that core material at the end of the electrode is vaporized by the arc. (Author) Edwards High Vacuum Int Ltd, German Patent 1,242,074, Parent Abstr, 7 (28) part 7, 19th July 1967, 1. 30 1693. Metal vacuum coating. (Germany) A metal wire is passed by a feed mechanism through a cooled guide to the deposition point and the end of the wire is melted dropwise and evaporated by means of electron bombardment. The guide nozzle is in a cooled component and the metal wire is conveyed vertically downwards through the guide. At the evaporating location a wire electrode producing electron beams is arranged so that the molten wire metal remains hanging in drops on the lower side of the cooled component. (Author) Edwards High Vacuum Ltd. German Patenf 1.242.429. Patent Abstr. 7 (29) part 7, 26th July 196?, 2. 30 1694. Metal sputtering. (Great Britain) The workpiece and sputter cathode, having at least a surface layer of the coating metal, are alternated as the cathode of a glow discharge by reversing polarities. The period between is greater than the time of deionization of the discharge gas and less than the time required for the metal atoms to travel from the cathode to the workpiece. It is possible to diffuse into the base metal (iron or steel) about l-2 per cent of the coating metal (chromium). Elektrophys Anst Bernhard Berghaus, Brit Patent 1,072,742, Patent Abstr, 7 (28) part 7, 14th July 1967, 3. AND SEALING
31 : 16 Removal of hydrogen impurities in closed noble gas discharge systems. See abstract number 1605.
31 : 18 Microwave noise oscillation radiation of anomalous discharge plasma. See abstract number 1617.
intensity from gas
31 1695. Vacuum switchgear ~ a survey. c USA) A survey of the literature and NASA Sponsored reports on vacuum switchgear is reported. Cited are two NASA sponsored studies dealing directly with the basic technology underlying ultrahigh vacuum suitable for applications such as vacuum interrupters: studies of adhesion mechanisms and the effect of surface preparation, pressure measurements, cathode and arc phenomena, and hardware development. An analysis of unsolved switching problems and requirements
(Westinghouse
Electric
Corp, 31
1696. Electron discharge device cathode.
(Great
Britain)
This includes a refractory metal heater an electron-emissive cathode located in heat exchange with respect to it. The heater, which may be in the form of a wire or coil, is preferably composed principally of tungsten and has a vapour-deposited insulating coating of alumina, beryllia or yttria. Varian Associates, Brit Patent 1,073,339, Parent Ab.rtr. 7 (28) part 6, 14th JU/JJ1967, 3. 32. NUCLEONICS 32 : 20 See abstract number 1636.
The vacuum system of OGRA-II.
32 : 21 Application of turbomolecular pumps to recently developed particle accelerators. See abstract number 1638. 32 1697. He, gas circulation system for the ion source of the RIKEN cyclotron
30
31. EVACUATION
is also included. W S Emmerich, Rep NASA-SP-5063 Pittsburgh, Pennsylvania).
with the result of its test by gas analysis.
(Japan)
Conventional ion sources for accelerating He3 ions in a cyclotron require a large gas influx. In the RIKEN 160 cm cyclotron, a circulation system has been devised to recover and purify the He3 continuously. This is accomplished by a 50 litre/min rotary pump which has vacuum-tight intake and exhaust. During He3 operation, this pump replaces a forepump of the cyclotron pumping system and delivers the gas to the ion source through a charcoal trap cooled by liquid nitrogen. The design of the system is such as to make the volume between the exhaust of the rotary pump and the ion source, as small as possible. Results of tests of the system performance using He4 (300 cc STP) are presented. T Tonuma et al, J Vat Sot Japan, 10 (6), June 1967, 228-233 (in Japanese). 32 1698. The all-glass
spark chamber.
(Holland)
A spark chamber with glass electrodes and with glass walls for experiments of extended duration, is described. These electrodes with vacuum evaporated metal layers can be used for more than IO* pulses without any significant changes in the performance. The voltage characteristic of the chamber are given and discussed. S Saro et al, Nucl Instrum Methods, 50 (I) April 1967, 11. 1699. Construction and operation (Holland) counters.
of thin parallel
plate proportion:
A proportional counter of parallel plate geometry with uniform gain, to within 10 and 100 per cent efficiency over a large area, is described. The unit has a gas gain of 500 for electron collection and several thousand for ion collection. The electron pulse risetime is 30 ns for an argon-methane mixture (P-10) or methane counter gas at 150 torr. The ion pulse risetime is about 5 microsec. The area is 50 cm2 and the effective thickness about 4 mg/cma, for a detector consisting of 3 nickel foils, each 1 micron thick and two 0.163 inch gaps containing the counter gas. These detectors have been used successfully in measuring proton polarizations; about lOO:l signalto-noise ratios were obtained for 5 MeV alpha particles. R H Hilberg et al, Nucl Instrum Methods, 50 (I), April 1967, 121-124. 32 1700. The University counters.
of Utah
neutriuo
detector ~ Cylindrical
spark
(Holland)
A cylindrical spark counter (CSC) 15 cm diameter and 11 m long with an 0.25 mm centre wire is discussed. A gas mixture of 2/3 argon and l/3 ethylene at a total pressure of 750 torr, results in a discharge sharply localized at the location of the initial ionization. Operation in the pulsed mode makes possible economies in construction and permits use of a sonic ranging system to locate the discharges with a precision of 3 mm. Several discharges can occur simultaneously at different positions in the counter. A prototype detector containing 115 CSC operated for 6 months, demonstrating the stability and long life of CSC. J W Keuffel and J L Parker, Nucl Instrum Methods, 51 (1), May 1967, 29-42.
561
abstracts
1690-1700 30 : 42
1690. The dielectric constant of zirconia.
(Great
Britain)
The value of the dielectric constant of zirconia, determined for the first time on single-crystals, is given as 22k3 and is almost independent of frequency from 100 c/s to 20 kc/s. This value is compared with the previous values obtained on films, which were in the range 12 to 25. P J Harrop and J N Wanklyn, 739-742.
Brif J Appl Phys,
18 (6), June 1967,
30 1691. Method and apparatus for cathode sputtering including suppressing temperature rise adjacent the anode using a localised magnetic fleld. (USA)
The apparatus positions the article in the sputter cathode and adjacent to the anode. A localized magnetic field is generated directly over the entire article surface and at right angles to the sputtering electric field. The article is cooled to enable the magnetic field strength to remain constant during the coating period. Charged particles are therefore deflected away from the article surface thus maintaining the article at a relatively low temperature. A rack and pinion is used to adjust the positional relationship in order to vary the cooling effect on the article. Int Business Mach Corp, US Patent 3,330,752, Ofice, 840 (2), 11th July 1967, 614.
Official Gaz US Patent
1692. Elongated electrode. (Germany) This has a core which is to be vaporized and a refractory shell, the core consisting of a mixture of platinum and carbon, and the refractory shell consisting of a material which does not evaporate in operation of the electrode to produce vapour from the core. In a vacuum deposition process, the electrode may be placed adjacent a second electrode, and an electric arc struck between the electrodes so that core material at the end of the electrode is vaporized by the arc. (Author) Edwards High Vacuum Int Ltd, German Patent 1,242,074, Parent Abstr, 7 (28) part 7, 19th July 1967, 1. 30 1693. Metal vacuum coating. (Germany) A metal wire is passed by a feed mechanism through a cooled guide to the deposition point and the end of the wire is melted dropwise and evaporated by means of electron bombardment. The guide nozzle is in a cooled component and the metal wire is conveyed vertically downwards through the guide. At the evaporating location a wire electrode producing electron beams is arranged so that the molten wire metal remains hanging in drops on the lower side of the cooled component. (Author) Edwards High Vacuum Ltd. German Patenf 1.242.429. Patent Abstr. 7 (29) part 7, 26th July 196?, 2. 30 1694. Metal sputtering. (Great Britain) The workpiece and sputter cathode, having at least a surface layer of the coating metal, are alternated as the cathode of a glow discharge by reversing polarities. The period between is greater than the time of deionization of the discharge gas and less than the time required for the metal atoms to travel from the cathode to the workpiece. It is possible to diffuse into the base metal (iron or steel) about l-2 per cent of the coating metal (chromium). Elektrophys Anst Bernhard Berghaus, Brit Patent 1,072,742, Patent Abstr, 7 (28) part 7, 14th July 1967, 3. AND SEALING
31 : 16 Removal of hydrogen impurities in closed noble gas discharge systems. See abstract number 1605.
31 : 18 Microwave noise oscillation radiation of anomalous discharge plasma. See abstract number 1617.
intensity from gas
31 1695. Vacuum switchgear ~ a survey. c USA) A survey of the literature and NASA Sponsored reports on vacuum switchgear is reported. Cited are two NASA sponsored studies dealing directly with the basic technology underlying ultrahigh vacuum suitable for applications such as vacuum interrupters: studies of adhesion mechanisms and the effect of surface preparation, pressure measurements, cathode and arc phenomena, and hardware development. An analysis of unsolved switching problems and requirements
(Westinghouse
Electric
Corp, 31
1696. Electron discharge device cathode.
(Great
Britain)
This includes a refractory metal heater an electron-emissive cathode located in heat exchange with respect to it. The heater, which may be in the form of a wire or coil, is preferably composed principally of tungsten and has a vapour-deposited insulating coating of alumina, beryllia or yttria. Varian Associates, Brit Patent 1,073,339, Parent Ab.rtr. 7 (28) part 6, 14th JU/JJ1967, 3. 32. NUCLEONICS 32 : 20 See abstract number 1636.
The vacuum system of OGRA-II.
32 : 21 Application of turbomolecular pumps to recently developed particle accelerators. See abstract number 1638. 32 1697. He, gas circulation system for the ion source of the RIKEN cyclotron
30
31. EVACUATION
is also included. W S Emmerich, Rep NASA-SP-5063 Pittsburgh, Pennsylvania).
with the result of its test by gas analysis.
(Japan)
Conventional ion sources for accelerating He3 ions in a cyclotron require a large gas influx. In the RIKEN 160 cm cyclotron, a circulation system has been devised to recover and purify the He3 continuously. This is accomplished by a 50 litre/min rotary pump which has vacuum-tight intake and exhaust. During He3 operation, this pump replaces a forepump of the cyclotron pumping system and delivers the gas to the ion source through a charcoal trap cooled by liquid nitrogen. The design of the system is such as to make the volume between the exhaust of the rotary pump and the ion source, as small as possible. Results of tests of the system performance using He4 (300 cc STP) are presented. T Tonuma et al, J Vat Sot Japan, 10 (6), June 1967, 228-233 (in Japanese). 32 1698. The all-glass
spark chamber.
(Holland)
A spark chamber with glass electrodes and with glass walls for experiments of extended duration, is described. These electrodes with vacuum evaporated metal layers can be used for more than IO* pulses without any significant changes in the performance. The voltage characteristic of the chamber are given and discussed. S Saro et al, Nucl Instrum Methods, 50 (I) April 1967, 11. 1699. Construction and operation (Holland) counters.
of thin parallel
plate proportion:
A proportional counter of parallel plate geometry with uniform gain, to within 10 and 100 per cent efficiency over a large area, is described. The unit has a gas gain of 500 for electron collection and several thousand for ion collection. The electron pulse risetime is 30 ns for an argon-methane mixture (P-10) or methane counter gas at 150 torr. The ion pulse risetime is about 5 microsec. The area is 50 cm2 and the effective thickness about 4 mg/cma, for a detector consisting of 3 nickel foils, each 1 micron thick and two 0.163 inch gaps containing the counter gas. These detectors have been used successfully in measuring proton polarizations; about lOO:l signalto-noise ratios were obtained for 5 MeV alpha particles. R H Hilberg et al, Nucl Instrum Methods, 50 (I), April 1967, 121-124. 32 1700. The University counters.
of Utah
neutriuo
detector ~ Cylindrical
spark
(Holland)
A cylindrical spark counter (CSC) 15 cm diameter and 11 m long with an 0.25 mm centre wire is discussed. A gas mixture of 2/3 argon and l/3 ethylene at a total pressure of 750 torr, results in a discharge sharply localized at the location of the initial ionization. Operation in the pulsed mode makes possible economies in construction and permits use of a sonic ranging system to locate the discharges with a precision of 3 mm. Several discharges can occur simultaneously at different positions in the counter. A prototype detector containing 115 CSC operated for 6 months, demonstrating the stability and long life of CSC. J W Keuffel and J L Parker, Nucl Instrum Methods, 51 (1), May 1967, 29-42.
561