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NRC produce improved form of tantalum
VACUUM
NEWS
Technical and Industrial
NRC produce improved form of tantalum
AUGUST,
Development and production of a new, greatly improved form of tantalum was announced on 2 July by National Research Corp., a subsidiary of Norton Co. The new tantalum, designated SGS (for Stable Grain Size), is said to be the first form of this metal to alleviate the problem of oxygen embrittlement accompanying excessive grain growth at high temperatures. Several other hightemperature advantages are said to be provided by the new metal. Its recrystallization temperature is described as about 12OO”C, compared with 1200°C for conventional tantalum ; it is also stated to have about 300 per cent greater high-temperature strength at 165O”C, with a comparable improvement in oxygen tolerance. After exposure in poor vacuums to temperatures of 1600°C to 22Oo”C, it is claimed to be still ductile and to be easily bent or handled ; and after 50 hours exposure to a temperature of about 21OO”C, it was said to show a grain size of two-thousandths of an inch diameter, about one thousand times smaller than that of normal tantalum under the same conditions. NRC consider that SGS tantalum will have a wide number of uses, such as for wire leads or caps used on capacitators, furnace elements and shields, and in piping used to handle liquid metals in nuclear reactors. Tests have shown that it has increased resistance to attack from molten fuels. It is available in all the forms in which standard tantalum is produced, such as capacitator-grade wire and strip, sheet, rod and seamless tubing, and is also available in alloy form. Patent applications have been filed. National Research Corp., Massachusetts, U.S.A.
IO Memorial
Developments
Drive,
1964
Technical and Industrial Developments New form of tantalum-industrial prod$ion bt liquid parahydrogen-pressure-to-vacuum bushing-200,000 counts per second scaler-improved NMR spectrometers-versatile French spectrometer-multiple evaporation source-electrobalance--chamberless metallizing plant-coldretort vacuum furnaces Vacuum Commercial News New British research pla&-Higd ‘Voltage En;;neering obtains large Western European orderNRC acquires semi-conductor company U.K.A.E.A.
Research Group
..
.
The Institute of Physics and The Physical Society
Page 303
306
..
306
..
307
l Manufacturers and others are invited to submit information for inclusion in this feature, addressed to the Vacuum News Editor Vacuum, Pergamon Press, 4 & 5 Fitzroy Square, London, W.1. l For further information on any matter mentioned in “ Vacuum News “, tear out and post one of the READER ENQUIRY SERVICE CARDS. Readers in the U.S.A. should use the cards addressed to New York ; all other readers are requested to use the cards addressed to London.
Cambridge,
_ Industrial production of liquid parahydrogen Liquid parahydrogen is now being supplied on an industrial scale for the first time in Great Britain by The British Oxygen Co. Ltd. It is stated to be stable at the storage temperature of 20°K and to contain at least 98 per cent of the para form. The Company claims that the only storage losses are insulation losses, and that even these are now being kept lower than 1 per cent a day in new storage tanks developed by the Company’s recently formed division, British Oxygen Cryoproducts. Conversion into the para form takes place automatically during the liquefaction process by means of a conversion catalyst made at the British Oxygen Scientific Centre at Morden, London. The British Oxygen Co. Ltd., Hammersmith House, London, W.6, Great Britain.
The feed-through unit, only 1 ft. long on the vacuum side by 21 cm in diameter, is described as having useful applications in high-voltage testing of equipment in vacuum, high-energy acceleration of charged particles in vacuum, and in studies of electro-nuclear generators. The unit is said to be able to support a large voltage per unit of volume through the concept of voltage grading employed in its design. On both the pressure and vacuum sides of the central grounded flange are columns about 30 cm long and 20 cm in outside diameter, constructed of alternate aluminium and Pyrex glass rings, bonded together with vinyl acetate to make a vacuumtight stack. The aluminium rings divide the surface into segments, each able to support about 60,000 V. The combined stack and metal flange are then lined with a resistive cylinder which fixes the potential of each aluminium ring. A central shaft connects the extremities of the stacks. The bushing is internally insulated with high-pressure gas to prevent flashover. The Company reports that the device has supported up to 1.2 million V at 1O-4 torr on the vacuum side. Ion Physics state that they are also offering 100 and 200 kV bushings, complete air-to-vacuum with mounting flange assemblies. The devices feature all-inorganic construction in the vacuum portion, permitting operation in environments below lo--’ torr without contamination.
Pressure-to-vacuum bushing A pressure-to-vacuum bushing rated at 600 kV, positive or negative polarity, has been developed by Ion Physics Corp., a subsidiary of High Voltage Engineering Corn. Three of the bushings-have already been-sold, the Company deports. Argonne National Laboratory and the CERN Research Centre in Switzerland are stated to be using the units for studies related to highenergy particle separators, and the National Aeronautics and Space Administration’s Lewis Research Center is stated to have bought one for use in aerospace thrustor studies.
Ion Physics Corp., Box 98, Burlington, Massachusetts, U.S.A. 305
NEWS
Technical and Industrial
NRC produce improved form of tantalum
AUGUST,
Development and production of a new, greatly improved form of tantalum was announced on 2 July by National Research Corp., a subsidiary of Norton Co. The new tantalum, designated SGS (for Stable Grain Size), is said to be the first form of this metal to alleviate the problem of oxygen embrittlement accompanying excessive grain growth at high temperatures. Several other hightemperature advantages are said to be provided by the new metal. Its recrystallization temperature is described as about 12OO”C, compared with 1200°C for conventional tantalum ; it is also stated to have about 300 per cent greater high-temperature strength at 165O”C, with a comparable improvement in oxygen tolerance. After exposure in poor vacuums to temperatures of 1600°C to 22Oo”C, it is claimed to be still ductile and to be easily bent or handled ; and after 50 hours exposure to a temperature of about 21OO”C, it was said to show a grain size of two-thousandths of an inch diameter, about one thousand times smaller than that of normal tantalum under the same conditions. NRC consider that SGS tantalum will have a wide number of uses, such as for wire leads or caps used on capacitators, furnace elements and shields, and in piping used to handle liquid metals in nuclear reactors. Tests have shown that it has increased resistance to attack from molten fuels. It is available in all the forms in which standard tantalum is produced, such as capacitator-grade wire and strip, sheet, rod and seamless tubing, and is also available in alloy form. Patent applications have been filed. National Research Corp., Massachusetts, U.S.A.
IO Memorial
Developments
Drive,
1964
Technical and Industrial Developments New form of tantalum-industrial prod$ion bt liquid parahydrogen-pressure-to-vacuum bushing-200,000 counts per second scaler-improved NMR spectrometers-versatile French spectrometer-multiple evaporation source-electrobalance--chamberless metallizing plant-coldretort vacuum furnaces Vacuum Commercial News New British research pla&-Higd ‘Voltage En;;neering obtains large Western European orderNRC acquires semi-conductor company U.K.A.E.A.
Research Group
..
.
The Institute of Physics and The Physical Society
Page 303
306
..
306
..
307
l Manufacturers and others are invited to submit information for inclusion in this feature, addressed to the Vacuum News Editor Vacuum, Pergamon Press, 4 & 5 Fitzroy Square, London, W.1. l For further information on any matter mentioned in “ Vacuum News “, tear out and post one of the READER ENQUIRY SERVICE CARDS. Readers in the U.S.A. should use the cards addressed to New York ; all other readers are requested to use the cards addressed to London.
Cambridge,
_ Industrial production of liquid parahydrogen Liquid parahydrogen is now being supplied on an industrial scale for the first time in Great Britain by The British Oxygen Co. Ltd. It is stated to be stable at the storage temperature of 20°K and to contain at least 98 per cent of the para form. The Company claims that the only storage losses are insulation losses, and that even these are now being kept lower than 1 per cent a day in new storage tanks developed by the Company’s recently formed division, British Oxygen Cryoproducts. Conversion into the para form takes place automatically during the liquefaction process by means of a conversion catalyst made at the British Oxygen Scientific Centre at Morden, London. The British Oxygen Co. Ltd., Hammersmith House, London, W.6, Great Britain.
The feed-through unit, only 1 ft. long on the vacuum side by 21 cm in diameter, is described as having useful applications in high-voltage testing of equipment in vacuum, high-energy acceleration of charged particles in vacuum, and in studies of electro-nuclear generators. The unit is said to be able to support a large voltage per unit of volume through the concept of voltage grading employed in its design. On both the pressure and vacuum sides of the central grounded flange are columns about 30 cm long and 20 cm in outside diameter, constructed of alternate aluminium and Pyrex glass rings, bonded together with vinyl acetate to make a vacuumtight stack. The aluminium rings divide the surface into segments, each able to support about 60,000 V. The combined stack and metal flange are then lined with a resistive cylinder which fixes the potential of each aluminium ring. A central shaft connects the extremities of the stacks. The bushing is internally insulated with high-pressure gas to prevent flashover. The Company reports that the device has supported up to 1.2 million V at 1O-4 torr on the vacuum side. Ion Physics state that they are also offering 100 and 200 kV bushings, complete air-to-vacuum with mounting flange assemblies. The devices feature all-inorganic construction in the vacuum portion, permitting operation in environments below lo--’ torr without contamination.
Pressure-to-vacuum bushing A pressure-to-vacuum bushing rated at 600 kV, positive or negative polarity, has been developed by Ion Physics Corp., a subsidiary of High Voltage Engineering Corn. Three of the bushings-have already been-sold, the Company deports. Argonne National Laboratory and the CERN Research Centre in Switzerland are stated to be using the units for studies related to highenergy particle separators, and the National Aeronautics and Space Administration’s Lewis Research Center is stated to have bought one for use in aerospace thrustor studies.
Ion Physics Corp., Box 98, Burlington, Massachusetts, U.S.A. 305