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490. Low-temperature hermetic electric feedthroughs
Classified abstracts
480-491
18 480. Spike cathode for field emission. (Germany) A cathode with outgrowing spikes may serve as a field emission source of electrons. An estimation is presented for the field concentration according to a regular array of spikes. NiSb and CrSb cathodes have been produced from a semiconductor InSb matrix containing needlelike metallic inclusions by etching-off a matrix layer. The spike cathodes were investigated in an experimental set-up with a special highfield cathode lens. A flow cryopump was installed forming a cooling jacket in order to approach ultrahigh vacuum conditions within the set-up and maintaining the pressure below lo-’ torr. The investigation of these cathodes reveals an irregular emission pattern corresponding to the imperfect cathode structure. Nevertheless, the performed experiments together with the theoretical considerations demonstrate the feasibility of spike cathodes. H Pfleiderer and H Rehme, Phys Stat Sol (a), 11 (l), May 1972, 153160. 18 481. Solution of the Laplace equation for a Penning discharge cell by the method of nonlinear parameters. (USSR) An approximative method of solution of the Dirichlet problem of the Laplace equation in a Penning discharge cell is given. The presented method enables one to calculate with the aid of a computer the potential at an arbitrary point in a Penning discharge cell. _ I V Lyudkevich and V I Gordiychuk, Zh Tekh Fiz, 42 (4), April 1972, 861-863
(in Russian).
19. RADIATION
the first stage, and vice versa in the second. When the rotor turns, the gas being evacuated passes along coaxial channels to the outside. The alternating arrangement increases the probability of a particular gas molecule being ‘seized’ and carried through from the entrance to the exit. The effect may be increased by careful choice of the shape and size of the grooves. V P Golubev and V S Kondrashev, USSR Patent No 325413, appl30th April 1970, publs 7th Jan 1972. 22. GAUGES
22 486. Vacuum gauge. (USSR) The new vacuum gauge here proposed differs from its predecessors in that, in order to increase the range of pressures measured and eliminate the effects of parasitic currents, the vacuum gauge sensor contains an electron injector and is supplied with a source of magnetic field, the configuration of the latter being chosen so that an adiabatic trap with magnetic mirrors is formed in the inside of the sensor. The injector is made in the form of an electron gun with a photocathode. The signal indicating the degree of vacuum may conveniently be taken from the secondary-particle current, which may be visualized as well as measured on an oscilloscope. G I Budker et al, USSR Patent No 322685, appl 10th June 1967, publd 13th March 1972. 22 487. Theory of symmetrical sector mass spectrometer. (USSR) Ion-optical properties of magnetic symmetrical sector mass spectrometers are considered. Equations for dispersion are obtained. V M Kelman et al, Zh Tekh Fiz, 42 (5), May 1972,963-968 (in Russian).
19 482. Investigations of luminescence spectrum of atomic iodine (2P1,22PJ,2 laser transition). (USSR) The luminescence spectrum of atomic iodine at wavelength of 1.315 pm is investigated in the photolysis of C3F31 at pressure of 2 x lo-’ atm. The hyperfine structure of the spectrum, obtained with the aid of Fabry-Perot interferometer placed in a vacuum chamber with pressure varying from 0.1 to 0.6 atm, is in good agreement with the calculations. V S Zuev et al, Zh Eksper Teor Fiz, 62 (5), May 1972, 1673-1680 (in
(USSR) An electrometer circuit with an electrometer tetrode is described which can be used for extending the measuring range of the ionization gauge control unit VIT-1 down to lo-” torr, using a BayardAlpert gauge head. Yu P Udoev, Prib Tekh Eksper, No 2, March-April 1972, 241-242 (in
Russian).
Russian).
22 488. Extending the measuring range of the gauge control unit VIT-1.
22
of the part of the calibrating curve of ionixation gauge
489. Indication
II. Vacuum 20. PUMPING
apparatus
and auxiliaries
SYSTEMS
20 483. Method of automatically monitoring the temperature of molten metals in vacuum furnaces. (USSR) The method here proposed for monitoring the temperature of molten metals in vacuum furnaces is based on measuring the electrical conductivity of the film of metal deposited on the inspection window; the signal received from the conductivity-measuring circuit is converted into a control signal which may be used both to check the direct readings of the conventional pyrometer and if necessary to change the furnace heating parameters. D I Lisovskii et al, USSR Parent No 323672, appl 28th April 1970, pub/d 11th Feb 1972.
MI-lo. (USSR) Construction and characteristics of a high-pressure ionization gauge type MI-10 are described. The tube has a linear characteristic in the range of 5 x 10m6 to 0.8 torr and its sensitivity is 1 x 10m4 A/torr. The tube has a non-burnout thoriacoated iridium filament with operating temperature of 1300°C. The gauge can be operated in air at 1 torr for more than 150 h. A method is presented which can be used for measurement of pressures up to 30 torr using this gauge. The dependence of the ion current on pressure decreases at pressures above 1 torr and the same value of the ion current corresponds to two levels of pressure. To discern in which part of the characteristic the tube is operating, it is recommended that the ion collector voltage be increased from - 50 to - 150 V. At pressures below 0.6 torr the ion current decreases due to shorter electron paths and above 0.7 torr the ion current increases due to enhancement of ion velocities. E A Penchko and L P Khavkin, Prib Tekh Eksper, No 2, March-April
21. PUMPS AND PUMP FLUIDS
1972, 141-143
484. Rotary vacuum pump. (USSR) A new rotary vacuum pump designed to serve longer with less noise is described. The valve is made in the form of a rotating shaft connected to the rotor by a pin passing through an eccentric hole in the latter. The inside of the body (barrel) is coated with an elastic material and the rotor carries projections interacting with the elastic coating as the rotor turns. As the shaft rotates, the rotor executes a circular progressive motion, while the valve oscillates. The contact between the projections and the elastic material ensures proper sealing of the working space. G P Tarasov. USSR Parent No 322524. CXDD~27th March 1970. _.oubld 1st Feb 1972:
23. PLUMBING
I
_.
21
molecular vacuum pump. (USSR) A multistage molecular vacuum pump operating on a new principle is described. A high compression and pumping speed are achieved by siting helical grooves in the rotor and making the stator smooth in
485. Multistage
298
(in Russian).
490. Low-temperature hermetic electric feedthroughs. (USSR)
23
Construction and results of examinations of electric feedthroughs from vacuum to a helium cryostat are described. Polymer resin is used for hermetic sealing of the feedthroughs. 0 P Anashkin, Prib Tekh Eksper, No 2, March-April 1972, 225 (in Russian).
491. Ultrahigh vacuum bakeable feedthrough. (USSR) Construction of a stainless steel bellows feedthrough for displacement of objects in conditions of ultrahigh vacuum, up to a distance of 700 mm, is described. The feedthrough is simple and it reliably operates in vacuum of lo- I2 torr with a leakage rate less than 5 x 10e8 &ec. The feedthrough is bakeable to 450°C. K D Danllov, Prib Tekh Eksper, No 2, March-April 1972, 150-151 (in Russian).
480-491
18 480. Spike cathode for field emission. (Germany) A cathode with outgrowing spikes may serve as a field emission source of electrons. An estimation is presented for the field concentration according to a regular array of spikes. NiSb and CrSb cathodes have been produced from a semiconductor InSb matrix containing needlelike metallic inclusions by etching-off a matrix layer. The spike cathodes were investigated in an experimental set-up with a special highfield cathode lens. A flow cryopump was installed forming a cooling jacket in order to approach ultrahigh vacuum conditions within the set-up and maintaining the pressure below lo-’ torr. The investigation of these cathodes reveals an irregular emission pattern corresponding to the imperfect cathode structure. Nevertheless, the performed experiments together with the theoretical considerations demonstrate the feasibility of spike cathodes. H Pfleiderer and H Rehme, Phys Stat Sol (a), 11 (l), May 1972, 153160. 18 481. Solution of the Laplace equation for a Penning discharge cell by the method of nonlinear parameters. (USSR) An approximative method of solution of the Dirichlet problem of the Laplace equation in a Penning discharge cell is given. The presented method enables one to calculate with the aid of a computer the potential at an arbitrary point in a Penning discharge cell. _ I V Lyudkevich and V I Gordiychuk, Zh Tekh Fiz, 42 (4), April 1972, 861-863
(in Russian).
19. RADIATION
the first stage, and vice versa in the second. When the rotor turns, the gas being evacuated passes along coaxial channels to the outside. The alternating arrangement increases the probability of a particular gas molecule being ‘seized’ and carried through from the entrance to the exit. The effect may be increased by careful choice of the shape and size of the grooves. V P Golubev and V S Kondrashev, USSR Patent No 325413, appl30th April 1970, publs 7th Jan 1972. 22. GAUGES
22 486. Vacuum gauge. (USSR) The new vacuum gauge here proposed differs from its predecessors in that, in order to increase the range of pressures measured and eliminate the effects of parasitic currents, the vacuum gauge sensor contains an electron injector and is supplied with a source of magnetic field, the configuration of the latter being chosen so that an adiabatic trap with magnetic mirrors is formed in the inside of the sensor. The injector is made in the form of an electron gun with a photocathode. The signal indicating the degree of vacuum may conveniently be taken from the secondary-particle current, which may be visualized as well as measured on an oscilloscope. G I Budker et al, USSR Patent No 322685, appl 10th June 1967, publd 13th March 1972. 22 487. Theory of symmetrical sector mass spectrometer. (USSR) Ion-optical properties of magnetic symmetrical sector mass spectrometers are considered. Equations for dispersion are obtained. V M Kelman et al, Zh Tekh Fiz, 42 (5), May 1972,963-968 (in Russian).
19 482. Investigations of luminescence spectrum of atomic iodine (2P1,22PJ,2 laser transition). (USSR) The luminescence spectrum of atomic iodine at wavelength of 1.315 pm is investigated in the photolysis of C3F31 at pressure of 2 x lo-’ atm. The hyperfine structure of the spectrum, obtained with the aid of Fabry-Perot interferometer placed in a vacuum chamber with pressure varying from 0.1 to 0.6 atm, is in good agreement with the calculations. V S Zuev et al, Zh Eksper Teor Fiz, 62 (5), May 1972, 1673-1680 (in
(USSR) An electrometer circuit with an electrometer tetrode is described which can be used for extending the measuring range of the ionization gauge control unit VIT-1 down to lo-” torr, using a BayardAlpert gauge head. Yu P Udoev, Prib Tekh Eksper, No 2, March-April 1972, 241-242 (in
Russian).
Russian).
22 488. Extending the measuring range of the gauge control unit VIT-1.
22
of the part of the calibrating curve of ionixation gauge
489. Indication
II. Vacuum 20. PUMPING
apparatus
and auxiliaries
SYSTEMS
20 483. Method of automatically monitoring the temperature of molten metals in vacuum furnaces. (USSR) The method here proposed for monitoring the temperature of molten metals in vacuum furnaces is based on measuring the electrical conductivity of the film of metal deposited on the inspection window; the signal received from the conductivity-measuring circuit is converted into a control signal which may be used both to check the direct readings of the conventional pyrometer and if necessary to change the furnace heating parameters. D I Lisovskii et al, USSR Parent No 323672, appl 28th April 1970, pub/d 11th Feb 1972.
MI-lo. (USSR) Construction and characteristics of a high-pressure ionization gauge type MI-10 are described. The tube has a linear characteristic in the range of 5 x 10m6 to 0.8 torr and its sensitivity is 1 x 10m4 A/torr. The tube has a non-burnout thoriacoated iridium filament with operating temperature of 1300°C. The gauge can be operated in air at 1 torr for more than 150 h. A method is presented which can be used for measurement of pressures up to 30 torr using this gauge. The dependence of the ion current on pressure decreases at pressures above 1 torr and the same value of the ion current corresponds to two levels of pressure. To discern in which part of the characteristic the tube is operating, it is recommended that the ion collector voltage be increased from - 50 to - 150 V. At pressures below 0.6 torr the ion current decreases due to shorter electron paths and above 0.7 torr the ion current increases due to enhancement of ion velocities. E A Penchko and L P Khavkin, Prib Tekh Eksper, No 2, March-April
21. PUMPS AND PUMP FLUIDS
1972, 141-143
484. Rotary vacuum pump. (USSR) A new rotary vacuum pump designed to serve longer with less noise is described. The valve is made in the form of a rotating shaft connected to the rotor by a pin passing through an eccentric hole in the latter. The inside of the body (barrel) is coated with an elastic material and the rotor carries projections interacting with the elastic coating as the rotor turns. As the shaft rotates, the rotor executes a circular progressive motion, while the valve oscillates. The contact between the projections and the elastic material ensures proper sealing of the working space. G P Tarasov. USSR Parent No 322524. CXDD~27th March 1970. _.oubld 1st Feb 1972:
23. PLUMBING
I
_.
21
molecular vacuum pump. (USSR) A multistage molecular vacuum pump operating on a new principle is described. A high compression and pumping speed are achieved by siting helical grooves in the rotor and making the stator smooth in
485. Multistage
298
(in Russian).
490. Low-temperature hermetic electric feedthroughs. (USSR)
23
Construction and results of examinations of electric feedthroughs from vacuum to a helium cryostat are described. Polymer resin is used for hermetic sealing of the feedthroughs. 0 P Anashkin, Prib Tekh Eksper, No 2, March-April 1972, 225 (in Russian).
491. Ultrahigh vacuum bakeable feedthrough. (USSR) Construction of a stainless steel bellows feedthrough for displacement of objects in conditions of ultrahigh vacuum, up to a distance of 700 mm, is described. The feedthrough is simple and it reliably operates in vacuum of lo- I2 torr with a leakage rate less than 5 x 10e8 &ec. The feedthrough is bakeable to 450°C. K D Danllov, Prib Tekh Eksper, No 2, March-April 1972, 150-151 (in Russian).