- Email: [email protected]
1669. High vacuum leak-valve
Classified
abstracts
1667-1678
turbine wheel for rotation. This wheel has a number of blades disposed around a peripheral portion with a radially extending surface formed at one side immediately adjacent the blade. A nozzle directs fluid onto the blade whereby the shaft will be rotated. The seal is a stationary face ring of fluid tightly joined to the housing and sealingly contacts the radial extending surface on a sealing circle. so that fluid expanding in the region of the blade will cause cooling of the seal. The Welch Scientific Co, US Patent 3,332,610, Official Gaz US Patent Ofice, 840 (4), 25th July 1967, 1219. 23 1667. High vacuum flange seals.
(Great
Britain)
These are suitable in high-pressure, demountable systems, consisting of a conduit with an annular flange for joining with another flange having a groove in the working face. A projection within the groove extends from the bottom of the groove a distance not less than half the depth and less than the full depth of the groove. The crosssectional area of the projection is in the range of 0.05 to 0.15 times the cross-sectional area of the groove. For a further adaptation, a joint can comprise two apertured flange members clamped together, aligned to allow the flow of a fluid through the flange members with a sealing ring under compression between. (Author) Gen Electric Co, Brit Patent 21st July 1967, 3.
1,073,722,
Patent
Abstr,
of a rotary
leadthrough
for ultrahigh
24 vacuum.
A simple, economic design of a rotary motion transmission device for ultrahigh vacuum systems is described. The rotor is separated from the stator by the wall of the vacuum system, the rotor being inside. The device allows variation in either sense from zero to maximum speed of rotation of a moving assembly placed inside the ultrahigh vacuum system. A feature of the device is the rotary commutator which ensures a sinusoidal field distribution. Also a couple of up to 1 m.kg may be applied to the rotating assembly by this means. Maximum rotary speeds of 600 revsimin were satisfactorilv obtained in a 150 litre chamber at pressures down to 5 x lo-r0 torr.R Saglio et ai,Le Kde, 22 (129), May-June 1967,161-164 (in French). 24 1669. High vacuum leak-valve.
(Great
Britain)
This is bakeable and suitable for introducing a very stable and small flow (approx lo-’ torr litre/sec) of gas into a vacuum system. It comprises a valve shell with an inlet and outlet, a valve seat and a single-beat lift-type valve member which is adapted for movement relative to the valve seat and engaged by it upon closure. The seat includes a retaining sleeve to locate the seat in the valve shell. A soft metal gasket is tight about the sleeve with a collar tight about the gasket. This gasket has a seating surface extending above the collar and sleeve and the valve member has an optically smooth closure surface facing the seating surface. (Author) Varian Associates, &it Patent 1,073,998, Patent Abstr, 7 (29) part B, 21st July 1967, 4. 25. BAFFLES,
TRAPS AND REFRIGERATION
1670. Cryostat Britain)
of a new type
EQUIPMENT
for superconducting
coils.
25 (Great
Saclay)
(USA)
Varian Associates, US Patent 3,331,975, Ofice, 840 (3), 18th Jury 1967, 979.
Oficial
Gaz
US Patent 28
28. HEATING
EQUIPMENT
AND THERMOMETERS
1674. Plasma electron beam heating source. (Japan) The characteristics of plasma electron beam generated by a tantalum hollow cathode in low pressure argon are described. With constant argon flow rate the current/voltage characteristics were found to be quite stable. By means of an optical pyrometer, the temperature of the tantalum cathode was found to be about 2400°K. With cathode to anode distance of 50 mm the maximum power density obtained was 3 kW/cmz without a focusing magnetic field. When this distance was very long, power densities of several tens of watts/cm2 could be obtained. With cathode to anode distance less than 80 mm, the thermal efficiency was more than 80 per cent. Over 50 per cent of the total heat loss was due to radiation from the cathode surface. S Kashu et al, J Yac Sot Japan, 10 (5), May 1967,183-189 (in Japanese). 28 1675. Calorimetric measurements of the temperature dependence of the specific heat of metals at high temperatures. (Czechoslovakia)
A high-temperature diathermic calorimeter for measuring the temperature dependence of the specific heat of metals by the method of primary heat input is described. Measured samples of diameter 18 x 30 mm are heated by nichrome wire. At low temperatures argon atmosphere is used and at temperatures up to 1,OOOC the furnace is evacuated down to 10-j torr. J Velisek and J Vrestal, Czech J Phys, A 17 (3), 1967, 251-255 (in Czech).
1676. Method of investigating the lifetime of antifrictional
in vacuum and in inert gas atmospheres (USSR)
at temperatures
28 coatings
up to 600°C.
A laboratory device is described for testing frictional properties of investigated coatings at temperatures 20 to 600°C in vacuum of the order of lo+ torr or in inert gas atmosphere. The measuring principle is based on rolling a sphere on a disc with the speed of 0.01 to 1 m/set and with the loading force of 0.25 to 4.5 kg. As an example, measured data of VNII-NP-229 antifrictional coating based on MO&, which may be used at temperatures up to 500°C are given. R M Matveevskiy and S A Popov, Zavodsk Lab, 33 (6), 1967,743-746 (in Russian).
Helium cryostats with wide neck and relatively low evaporation rate are described. The combination of the functions “heat bridge” and radiation shield in a single constructive element allows the use of such cryostats without nitrogen shielding. The cryostat with inner diameter 200 mm evaporates about 700 cms/hr of liquid helium. It is possible to achieve considerable decrease in evaporation rate by using additional liquid nitrogen shielding. W E Keilin, Cryogenics, 7 (l), Fe6 1967, 3. 25 1671. Cryogenic equipment. (France) The cryostats described were built from standard parts. The liquid nitrogen and helium reservoirs were designed so as to reduce losses to a minimum and to make the cryostats as autonomous as possible. The experimental enclosure which is generally placed in the lower part of the apparatus requires a separate study in every case. L Leger et al, Rep CEA-R-3008, June 1966 (Commissariat a C’Energie Atomique,
method.
7 (29) part B,
24. VALVES 1668. Development (France)
1672. Cryogenic
For providing a surface at a cryogenic temperature, the cold wall chamber must be evacuated and supplied with a flow of cryogenic coolant. By regulating it to cause instant evaporation, the formation of a liquid coolant bath can be prevented and the evaporated coolant can be-removed from the cold wall with evacuation means. G KliDDiW. US Patent 3.330.125. Official Gaz US Patent Ofice. _” 840 “” (2), 1i;h &ly 1967, 435. 25 1673. Cooling apparatus for cathode getter pumps. (USA) A glow discharge apparatus consists of an anode electrode with a number of openings making a number of glow discharge passageways arranged in a pattern and grouped transversely to the longitudinal axes. The cooled cathode has parts opposite the discharge passageways. The cooling form in a non-linear shape is determined by the pattern of the discharge passageways.
(in French).
28 1677. Apparatus for measuring the absolute thermo-emf of metals and semiconductors in the temperature range 20 to 2,500”C. (USSR)
Type TVV-4 furnace which can reach 2500°C at 1 x 1O-4 torr was employed and the design of the measuring head is described. Temperatures were measured by WRe 5jWRe 20 thermocouple, experimentally calibrated up to 18OO”C, and the calibrating curve was extended to higher temperatures using data from literature. Measured values of the absolute thermo-emf of tungsten single crystal at temperatures up to 2200°C are given. 0 A Golikova et al, Zavodsk Lab, 33 (6), 1967, 772-774 (in Russian) 28 1678. Laboratory
high-temperature
The design of a furnace molybdenum temperature by VM-1 diffusion pump Both chambers, connected
vacuum furnace.
(USSR)
with tungsten heaters and tungsten or shields in one chamber and a basin filled oil in the second chamber is described. by a slide-valve, are pumped by a diffusion 579
abstracts
1667-1678
turbine wheel for rotation. This wheel has a number of blades disposed around a peripheral portion with a radially extending surface formed at one side immediately adjacent the blade. A nozzle directs fluid onto the blade whereby the shaft will be rotated. The seal is a stationary face ring of fluid tightly joined to the housing and sealingly contacts the radial extending surface on a sealing circle. so that fluid expanding in the region of the blade will cause cooling of the seal. The Welch Scientific Co, US Patent 3,332,610, Official Gaz US Patent Ofice, 840 (4), 25th July 1967, 1219. 23 1667. High vacuum flange seals.
(Great
Britain)
These are suitable in high-pressure, demountable systems, consisting of a conduit with an annular flange for joining with another flange having a groove in the working face. A projection within the groove extends from the bottom of the groove a distance not less than half the depth and less than the full depth of the groove. The crosssectional area of the projection is in the range of 0.05 to 0.15 times the cross-sectional area of the groove. For a further adaptation, a joint can comprise two apertured flange members clamped together, aligned to allow the flow of a fluid through the flange members with a sealing ring under compression between. (Author) Gen Electric Co, Brit Patent 21st July 1967, 3.
1,073,722,
Patent
Abstr,
of a rotary
leadthrough
for ultrahigh
24 vacuum.
A simple, economic design of a rotary motion transmission device for ultrahigh vacuum systems is described. The rotor is separated from the stator by the wall of the vacuum system, the rotor being inside. The device allows variation in either sense from zero to maximum speed of rotation of a moving assembly placed inside the ultrahigh vacuum system. A feature of the device is the rotary commutator which ensures a sinusoidal field distribution. Also a couple of up to 1 m.kg may be applied to the rotating assembly by this means. Maximum rotary speeds of 600 revsimin were satisfactorilv obtained in a 150 litre chamber at pressures down to 5 x lo-r0 torr.R Saglio et ai,Le Kde, 22 (129), May-June 1967,161-164 (in French). 24 1669. High vacuum leak-valve.
(Great
Britain)
This is bakeable and suitable for introducing a very stable and small flow (approx lo-’ torr litre/sec) of gas into a vacuum system. It comprises a valve shell with an inlet and outlet, a valve seat and a single-beat lift-type valve member which is adapted for movement relative to the valve seat and engaged by it upon closure. The seat includes a retaining sleeve to locate the seat in the valve shell. A soft metal gasket is tight about the sleeve with a collar tight about the gasket. This gasket has a seating surface extending above the collar and sleeve and the valve member has an optically smooth closure surface facing the seating surface. (Author) Varian Associates, &it Patent 1,073,998, Patent Abstr, 7 (29) part B, 21st July 1967, 4. 25. BAFFLES,
TRAPS AND REFRIGERATION
1670. Cryostat Britain)
of a new type
EQUIPMENT
for superconducting
coils.
25 (Great
Saclay)
(USA)
Varian Associates, US Patent 3,331,975, Ofice, 840 (3), 18th Jury 1967, 979.
Oficial
Gaz
US Patent 28
28. HEATING
EQUIPMENT
AND THERMOMETERS
1674. Plasma electron beam heating source. (Japan) The characteristics of plasma electron beam generated by a tantalum hollow cathode in low pressure argon are described. With constant argon flow rate the current/voltage characteristics were found to be quite stable. By means of an optical pyrometer, the temperature of the tantalum cathode was found to be about 2400°K. With cathode to anode distance of 50 mm the maximum power density obtained was 3 kW/cmz without a focusing magnetic field. When this distance was very long, power densities of several tens of watts/cm2 could be obtained. With cathode to anode distance less than 80 mm, the thermal efficiency was more than 80 per cent. Over 50 per cent of the total heat loss was due to radiation from the cathode surface. S Kashu et al, J Yac Sot Japan, 10 (5), May 1967,183-189 (in Japanese). 28 1675. Calorimetric measurements of the temperature dependence of the specific heat of metals at high temperatures. (Czechoslovakia)
A high-temperature diathermic calorimeter for measuring the temperature dependence of the specific heat of metals by the method of primary heat input is described. Measured samples of diameter 18 x 30 mm are heated by nichrome wire. At low temperatures argon atmosphere is used and at temperatures up to 1,OOOC the furnace is evacuated down to 10-j torr. J Velisek and J Vrestal, Czech J Phys, A 17 (3), 1967, 251-255 (in Czech).
1676. Method of investigating the lifetime of antifrictional
in vacuum and in inert gas atmospheres (USSR)
at temperatures
28 coatings
up to 600°C.
A laboratory device is described for testing frictional properties of investigated coatings at temperatures 20 to 600°C in vacuum of the order of lo+ torr or in inert gas atmosphere. The measuring principle is based on rolling a sphere on a disc with the speed of 0.01 to 1 m/set and with the loading force of 0.25 to 4.5 kg. As an example, measured data of VNII-NP-229 antifrictional coating based on MO&, which may be used at temperatures up to 500°C are given. R M Matveevskiy and S A Popov, Zavodsk Lab, 33 (6), 1967,743-746 (in Russian).
Helium cryostats with wide neck and relatively low evaporation rate are described. The combination of the functions “heat bridge” and radiation shield in a single constructive element allows the use of such cryostats without nitrogen shielding. The cryostat with inner diameter 200 mm evaporates about 700 cms/hr of liquid helium. It is possible to achieve considerable decrease in evaporation rate by using additional liquid nitrogen shielding. W E Keilin, Cryogenics, 7 (l), Fe6 1967, 3. 25 1671. Cryogenic equipment. (France) The cryostats described were built from standard parts. The liquid nitrogen and helium reservoirs were designed so as to reduce losses to a minimum and to make the cryostats as autonomous as possible. The experimental enclosure which is generally placed in the lower part of the apparatus requires a separate study in every case. L Leger et al, Rep CEA-R-3008, June 1966 (Commissariat a C’Energie Atomique,
method.
7 (29) part B,
24. VALVES 1668. Development (France)
1672. Cryogenic
For providing a surface at a cryogenic temperature, the cold wall chamber must be evacuated and supplied with a flow of cryogenic coolant. By regulating it to cause instant evaporation, the formation of a liquid coolant bath can be prevented and the evaporated coolant can be-removed from the cold wall with evacuation means. G KliDDiW. US Patent 3.330.125. Official Gaz US Patent Ofice. _” 840 “” (2), 1i;h &ly 1967, 435. 25 1673. Cooling apparatus for cathode getter pumps. (USA) A glow discharge apparatus consists of an anode electrode with a number of openings making a number of glow discharge passageways arranged in a pattern and grouped transversely to the longitudinal axes. The cooled cathode has parts opposite the discharge passageways. The cooling form in a non-linear shape is determined by the pattern of the discharge passageways.
(in French).
28 1677. Apparatus for measuring the absolute thermo-emf of metals and semiconductors in the temperature range 20 to 2,500”C. (USSR)
Type TVV-4 furnace which can reach 2500°C at 1 x 1O-4 torr was employed and the design of the measuring head is described. Temperatures were measured by WRe 5jWRe 20 thermocouple, experimentally calibrated up to 18OO”C, and the calibrating curve was extended to higher temperatures using data from literature. Measured values of the absolute thermo-emf of tungsten single crystal at temperatures up to 2200°C are given. 0 A Golikova et al, Zavodsk Lab, 33 (6), 1967, 772-774 (in Russian) 28 1678. Laboratory
high-temperature
The design of a furnace molybdenum temperature by VM-1 diffusion pump Both chambers, connected
vacuum furnace.
(USSR)
with tungsten heaters and tungsten or shields in one chamber and a basin filled oil in the second chamber is described. by a slide-valve, are pumped by a diffusion 579