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Vacuum pump
Classified
abstracts
1359-1371
walls, and permits the production of residual pressures of about lo-I0 torr in large vessels by means of small vacuum pumps without the need for stoving. (Author) Comm L’Energie Atomique, Brit Patent (19)part A, 12th May 1967, 4.
21. PUMPS
AND PUMP
1,066,127,
Patent
Abstr,
7
FLUIDS 21
: 33
(France) Pumping systems for electron microscopes were investigated by measuring the thickness of polymer film formed by electron bombardment and using this as a measure of the contamination at pressures below 1O-3 torr. At higher pressures use of a quartz crystal microbalance at liquid nitrogen temperatures was an alternative technique. The effect of different traps in the high vacuum side of the system and the influence of roughing with and without trapping devices, was determined. The transition from roughing to diffusion pumping was studied and an analysis of the results forms the basis for recommendations regarding the use of different traps and for defining a pumping cycle which minimizes at all times the contamination inside a microscope. 1359. Contamination
from pumping systems.
M Baker et al, Le Vide, 22 (127), Jan-Fe6
1967, 22-27 (in French).
1360. Investigation (Germany)
from oil diffusion
of the hack-streaming
21 pumps.
A mass spectrometric method is described for the quantitative analysis of the pump fluid constituents back-streaming from a diffusion pump. Cracking of the unknown residual gas by hot filaments is prevented completely during the measurement of total pressure and to a large extent during the measurement of partial pressure. The backstreaming gas is accumulated in a liquid-helium or liquid-nitrogen cooled trap over a lengthy period of time. When the container is isolated at the end of the trapping time and warmed up, the pressure rises to such an extent that it can be measured with a quartz fibre gauge. It was found that the main constituents of the residual gas in the case of Octoil S were hydrogen and carbon dioxide. In the case of DC 705 the cracked products of the DC 705 and hydrogen were obtained. No evidence of CO was found in the back-streaming gas. When operating the diffusion pump with Octoil S, the back-streaming rate was bv a factor of 300 higher than when oneratinn with DC 705. H Schulze;
I’akuum-Technik,
16 (5), April 196f
1361. Monte Carlo computations test domes. (Great Britain)
on molecular
102-1?l9 (in English). 21 : 14 Row in pumping speed
A test dome for pumping speed measurements on sputter-ion pumps is described. Results of Monte Carlo computations are presented which give for this dome the correlation between the intrinsic pumping speed and the pressures as measured in the dome. In particular, the influence of gauge position on speed measurement has been investigated as well as the influence of the geometry of the pump under test. The pump geometry affects the angular distribution of the molecules re-entering the dome from the pump side. It is shown that this influence is in most cases negligible. E Fischer and H Mommsen, Vacuum, 17 (6), June 1967, 309-315. 21 : 27 1362. A dual-purpose unit for high vacuum pumping system and leak detection in vacuum chambers. (Pakistan) An apparatus using conventional mechanical and vapour pumps was built which can be used as an exhaust system as well as a leak detector. Constructional principles and working instructions are given separately for the pumping and leak detection applications. J C Dutt et al, Rep AECDIEP/ll, March 1966 (Atomic Energy Centre,
Dacca, Pakistan).
1363. Micro-volumetric pump. (USA)
measurements
with
an
automatic
21 Toepler
484
I A Grishaev et al, Zh Tekh Fiz, 37 (4), April 1967,696-702
(in Russian). ‘I
1365. Vacuum pump apparatus.
(USA)
The inlet port of a diffusion pump is adapted for connection to a chamber, and an exhaust port allows the pumped gases to pass through an exhaust tubulation, which is heated in order to inhibit condensation of the gas and vapour, expelled through the exhaust port. Leybold Holding A G, US Patent 3,317,122, Office, 838 (l), 2nd May 1967, 191.
Oficial
Gaz US PatelIt 21
(USA) The sputtered cold cathode grid for a magnetically confined glow discharge apparatus extends outward from a cold cathode base plate. The grid includes a number of spaced-apart, concentrically disposed frustoconical elements of increasing radius, each having a surface portion exposed to relatively intense ion bombardment. The angle which the surface portion of an element makes with the base plate decreases with increase in radius of the element. 1366. Ion vacuum pumps.
Varian Associates, US Patent 3,319,875, 838 (3), 16th Ma_v 1967, 1014.
Official Gaz USPatent
Ofice, 21
(USA) The upper end of an oil diffusion pump is connected to a vacuum chamber with the lower end having an oil reservoir. A rotatable shaft extends concentrically within and through the pump with an oil face seal surrounding the shaft at the lower end. A second oil reservoir surrounds the seal with a means for transporting oil from the first to the second reservoir. 1367. Sealing mechanism
for an oil diffusion pump.
North American Aviation Inc, US Patent 3,319,876, Patent Ofice, 838 (3), 16th May 1967, 1014.
Official Gaz US
21 1368. Vacuum ion pump. (Germany) In an ion pump of the cellular anode type, the pumping action is improved by having the spaces between the anodes and associated cathodes diverging towards a port for communication with an atmosphere to be pumped. In an example, an anode is spaced in this way from two cathode surfaces at respective sides of the anode. PhiliDs Gloeilamuenfah. NV. German Patent 1.238.608. , , Patent Abstr. 7 (26) part C, 26th Ma> 1987, 10. 21
(Great Britain) The cathode consists of a planar ion-sorbing element and the anode of an annular element, sub-divided into a number of individual cells extending parallel to the longitudinal axis. Elongation of the electron path is caused by a magnetic field. If applied to a high frequency discharge device, it is enclosed in the drift tube section to be free of electric fields, thus minimizing any adverse effect of the pump structure on the electrical operation of the device. General Electric Co, Brit Patent 1,064,146, Patent Abstr, 7 (17)part C, 28th April 1967, 4. 1369. Ion pump.
21
(Great Britain) In pumps of the diffusion type, where oil vapour is downwardly discharged from a nozzle carried on a chimney etc, which has both inner and outer cowls for intercepting vapour, the operation is improved by having the inner cowl uncooled and the outer sufficiently cooled to condense the vapour. Leybold Holding AG, Brit Patent 1,064,429, Patent Abstr, 7 (17) part B, 1370. Vacuum pump.
28th April 1967, 3.
To eliminate contamination of the mercury the pump was constructed without greased stopcocks in the critical areas where mercury contacts the glass. The design of the pump eliminates arcing and provides possibilities for varying the time of the pumping cycle. A schematic of the control box is also presented. R N Dietz, Rev Sci Znstrum, 38 (3), March
21 : 32 1364. Use of getter-ion pumps for pumping of linear electron accelerators. (USSR) The vacuum system of 2,OQO MeV linear accelerator is briefly described. Every section is pumped by getter-ion pumps with a Ti evaporation rate of 0.06 mg/min and a pumping speed of 50 litre/sec for air. Every pump is connected to the system by a valve so that any pump may be exchanged without influencing the system pressure. Properties of these pumps and residual atmosphere mass spectra are given.
1967, 419421.
21
(Great Britain) The stator and rotor are provided with an even number of equiangular, radial movable vanes so that each stator vane is always in contact with at least one rotor vane to separate the sections. The stator vanes are interconnected by deformable guiding members which consist of 1371. Rotary pump.
abstracts
1359-1371
walls, and permits the production of residual pressures of about lo-I0 torr in large vessels by means of small vacuum pumps without the need for stoving. (Author) Comm L’Energie Atomique, Brit Patent (19)part A, 12th May 1967, 4.
21. PUMPS
AND PUMP
1,066,127,
Patent
Abstr,
7
FLUIDS 21
: 33
(France) Pumping systems for electron microscopes were investigated by measuring the thickness of polymer film formed by electron bombardment and using this as a measure of the contamination at pressures below 1O-3 torr. At higher pressures use of a quartz crystal microbalance at liquid nitrogen temperatures was an alternative technique. The effect of different traps in the high vacuum side of the system and the influence of roughing with and without trapping devices, was determined. The transition from roughing to diffusion pumping was studied and an analysis of the results forms the basis for recommendations regarding the use of different traps and for defining a pumping cycle which minimizes at all times the contamination inside a microscope. 1359. Contamination
from pumping systems.
M Baker et al, Le Vide, 22 (127), Jan-Fe6
1967, 22-27 (in French).
1360. Investigation (Germany)
from oil diffusion
of the hack-streaming
21 pumps.
A mass spectrometric method is described for the quantitative analysis of the pump fluid constituents back-streaming from a diffusion pump. Cracking of the unknown residual gas by hot filaments is prevented completely during the measurement of total pressure and to a large extent during the measurement of partial pressure. The backstreaming gas is accumulated in a liquid-helium or liquid-nitrogen cooled trap over a lengthy period of time. When the container is isolated at the end of the trapping time and warmed up, the pressure rises to such an extent that it can be measured with a quartz fibre gauge. It was found that the main constituents of the residual gas in the case of Octoil S were hydrogen and carbon dioxide. In the case of DC 705 the cracked products of the DC 705 and hydrogen were obtained. No evidence of CO was found in the back-streaming gas. When operating the diffusion pump with Octoil S, the back-streaming rate was bv a factor of 300 higher than when oneratinn with DC 705. H Schulze;
I’akuum-Technik,
16 (5), April 196f
1361. Monte Carlo computations test domes. (Great Britain)
on molecular
102-1?l9 (in English). 21 : 14 Row in pumping speed
A test dome for pumping speed measurements on sputter-ion pumps is described. Results of Monte Carlo computations are presented which give for this dome the correlation between the intrinsic pumping speed and the pressures as measured in the dome. In particular, the influence of gauge position on speed measurement has been investigated as well as the influence of the geometry of the pump under test. The pump geometry affects the angular distribution of the molecules re-entering the dome from the pump side. It is shown that this influence is in most cases negligible. E Fischer and H Mommsen, Vacuum, 17 (6), June 1967, 309-315. 21 : 27 1362. A dual-purpose unit for high vacuum pumping system and leak detection in vacuum chambers. (Pakistan) An apparatus using conventional mechanical and vapour pumps was built which can be used as an exhaust system as well as a leak detector. Constructional principles and working instructions are given separately for the pumping and leak detection applications. J C Dutt et al, Rep AECDIEP/ll, March 1966 (Atomic Energy Centre,
Dacca, Pakistan).
1363. Micro-volumetric pump. (USA)
measurements
with
an
automatic
21 Toepler
484
I A Grishaev et al, Zh Tekh Fiz, 37 (4), April 1967,696-702
(in Russian). ‘I
1365. Vacuum pump apparatus.
(USA)
The inlet port of a diffusion pump is adapted for connection to a chamber, and an exhaust port allows the pumped gases to pass through an exhaust tubulation, which is heated in order to inhibit condensation of the gas and vapour, expelled through the exhaust port. Leybold Holding A G, US Patent 3,317,122, Office, 838 (l), 2nd May 1967, 191.
Oficial
Gaz US PatelIt 21
(USA) The sputtered cold cathode grid for a magnetically confined glow discharge apparatus extends outward from a cold cathode base plate. The grid includes a number of spaced-apart, concentrically disposed frustoconical elements of increasing radius, each having a surface portion exposed to relatively intense ion bombardment. The angle which the surface portion of an element makes with the base plate decreases with increase in radius of the element. 1366. Ion vacuum pumps.
Varian Associates, US Patent 3,319,875, 838 (3), 16th Ma_v 1967, 1014.
Official Gaz USPatent
Ofice, 21
(USA) The upper end of an oil diffusion pump is connected to a vacuum chamber with the lower end having an oil reservoir. A rotatable shaft extends concentrically within and through the pump with an oil face seal surrounding the shaft at the lower end. A second oil reservoir surrounds the seal with a means for transporting oil from the first to the second reservoir. 1367. Sealing mechanism
for an oil diffusion pump.
North American Aviation Inc, US Patent 3,319,876, Patent Ofice, 838 (3), 16th May 1967, 1014.
Official Gaz US
21 1368. Vacuum ion pump. (Germany) In an ion pump of the cellular anode type, the pumping action is improved by having the spaces between the anodes and associated cathodes diverging towards a port for communication with an atmosphere to be pumped. In an example, an anode is spaced in this way from two cathode surfaces at respective sides of the anode. PhiliDs Gloeilamuenfah. NV. German Patent 1.238.608. , , Patent Abstr. 7 (26) part C, 26th Ma> 1987, 10. 21
(Great Britain) The cathode consists of a planar ion-sorbing element and the anode of an annular element, sub-divided into a number of individual cells extending parallel to the longitudinal axis. Elongation of the electron path is caused by a magnetic field. If applied to a high frequency discharge device, it is enclosed in the drift tube section to be free of electric fields, thus minimizing any adverse effect of the pump structure on the electrical operation of the device. General Electric Co, Brit Patent 1,064,146, Patent Abstr, 7 (17)part C, 28th April 1967, 4. 1369. Ion pump.
21
(Great Britain) In pumps of the diffusion type, where oil vapour is downwardly discharged from a nozzle carried on a chimney etc, which has both inner and outer cowls for intercepting vapour, the operation is improved by having the inner cowl uncooled and the outer sufficiently cooled to condense the vapour. Leybold Holding AG, Brit Patent 1,064,429, Patent Abstr, 7 (17) part B, 1370. Vacuum pump.
28th April 1967, 3.
To eliminate contamination of the mercury the pump was constructed without greased stopcocks in the critical areas where mercury contacts the glass. The design of the pump eliminates arcing and provides possibilities for varying the time of the pumping cycle. A schematic of the control box is also presented. R N Dietz, Rev Sci Znstrum, 38 (3), March
21 : 32 1364. Use of getter-ion pumps for pumping of linear electron accelerators. (USSR) The vacuum system of 2,OQO MeV linear accelerator is briefly described. Every section is pumped by getter-ion pumps with a Ti evaporation rate of 0.06 mg/min and a pumping speed of 50 litre/sec for air. Every pump is connected to the system by a valve so that any pump may be exchanged without influencing the system pressure. Properties of these pumps and residual atmosphere mass spectra are given.
1967, 419421.
21
(Great Britain) The stator and rotor are provided with an even number of equiangular, radial movable vanes so that each stator vane is always in contact with at least one rotor vane to separate the sections. The stator vanes are interconnected by deformable guiding members which consist of 1371. Rotary pump.