Abstract: A regenerable cryosorption pump with a movable physical barrier in which the barrier includes a cylindrical body closed at one end and having a circumferential baffle around the open end. The baffle engages a flange on the hydrogen isotope condensing and pumping surface to require all gases entering the pump during normal operation to pass through the hydrogen isotope condensing and pumping surface, thus avoiding bypass of that surface. The barrier is advanced by a bellows system to isolate the hydrogen isotope condensing and pumping surface from the sorbent surface during regeneration and thus ensuring separation of hydrogen isotopes such as tritium from helium which is sorbed onto the sorbent surface.

Abstract: A cryopump which has three temperature stages for pumping gas. The third temperature stage is surrounded by and separated from the second temperature stage which is surrounded by and separated from the first temperature stage. Adsorbent placed on the second and third stage are operated at different temperatures to prevent gases with higher critical mobility temperatures from becoming immobilized at the entrance of pores and wells along the surface of the adsorbent.

Abstract: Apparatus comprising a bakeable high vacuum system using cryopumps is disclosed. Auxiliary cooling means in thermal contact with the primary pumping stage of the cryopump remove heat from the cryopump, whereby the walls of the cryopump may be heated during operation of the cryopump, such that the cryopump can be baked. This can result in substantially improved attainable pressure in the system.

Abstract: Method and apparatus for transporting particulate material through a pipeline. The particles have a size distribution which provides a solids density of at least 85%. The particular have a maximum size of 20% of the bore.

Abstract: A vibration isolator particularly suited to isolating a closed cycle refrigerator in a cryopump includes two bellows covered with vibration damping material and separated by an intermediate mass. The damping material fills the spaces between corrugations of the bellows and is bonded to the bellows. A dynamic absorber operates to attenuate vibrations of a partucular frequency from being transmitted into the refrigerator from a drive unit of the cryopump.

Abstract: A two mass vibration isolator particularly suited to a linear reciprocating machine. Vibration into and out of the machine is attenuated by an isolator placed between the machine and its mounting frame. The isolator is an elastomer with a damping ratio of at least 0.1 sandwiched between two retainers.

Abstract: In a vacuum system having a load lock cooperating with a work chamber, a flow line is connected between the cryopump of the load lock and the work chamber. The flow line passes noncondensible gases which are not absorbed by the cryopump of the load lock to the work chamber 12 for absorption by the cryopump of the work chamber. Alternatively, the flow line is connected between the load lock cryopump and the cryopump of the work chamber for directly passing the noncondensible gases to the work chamber cryopump. The flow line prevents buildup of noncondensible gases within the cryopump of the load lock. The flow line may include baffles to damp pressure surges during cryopumping of the load lock. A control valve connected to the flow line allows operator control of the passing of noncondensible gases from the load lock cryopump to the work chamber or to the work chamber cryopump through the flow line. The dimensions of the flow line provide molecular flow of the noncondensible gases.

Abstract: A removable pump assembly for use in a cryogenic storage tank pumps liquid cryogen directly from the primary storage container with low boiloff loss. The cryogenic storage tank has an outer vessel, an inner vessel, an evacuated insulation space therebetween and a access port connecting the inner and outer vessels and providing an open cylindrical access to the interior of the cryogenic tank. A pump mounting tube assembly is disposed into the interior of the inner vessel of the cryogenic tank through the access port and includes an inner pump mounting tube and an outer pump mounting tube which are joined at their upper and lower rims to define an insulating jacket between the two tubes. The inner and outer pump mounting tubes are affixed at their upper ends to a top and bottom plate. The top and bottom plate in turn is affixed to an insulating block. Only the insulating block, which is disposed in the access port of the cryogenic tube, is in contact with any portion of the cryogenic tank.

Abstract: An improved cryopump for the removal of gases from a high vacuum, comprising a cryopanel incorporating honeycomb structure, refrigerant means thermally connected to the cryopanel, and a rotatable channel moving azimuthally around an axis located near the center of the cryopanel, removing gases absorbed within the honeycomb structure by subliming them and conducting them outside the vacuum vessel.

Abstract: A vibration isolator particularly suited to isolating a closed cycle refrigerator in a cryopump includes two bellows covered with vibration damping material and separated by an intermediate mass. The damping material fills the spaces between corrugations of the bellows and is bonded to the bellows.

Abstract: A two stage cryopump with an improved first stage for condensing water vapor at high speed independently of the rate of gas flow into the second stage and without increasing the heat load on the cryopump. The cryopump utilizes a low profile high precision variable aperture to control flow to a lower baffle obstructing the mouth of a shroud containing the second stage, utilizes a support shaft mounted on the top of the lower baffle and extending upstream through the aperture, and utilizes an upper baffle mounted on the top of the shaft in thermal contact with the lower baffle to condense water vapor before reaching the aperture.

Abstract: A reciprocating pump for a cryogenic fluid includes a pump cylinder made of a material with low thermal expansivity, a piston displaceable in the pump cylinder, and self-lubricating piston rings made of polytetrafluorethylene held on the circumferential surface of the piston. The rings have a larger thermal expansivity than the pump cylinder. The arrangement allows optimum matching of piston rings and pump cylinder at cryogenic fluid pumping temperatures. The piston has a core made of a material with relatively large thermal expansivity which is surrounded by a spacer sleeve made of a material with a low coefficient of thermal expansion. The core protrudes on both sides from the spacer sleeve and has expanding regions increasing conically towards its free ends. The piston rings surround the core in the expanding regions and are supported against the end faces of spacer sleeve. The conical expanding regions bias the rings toward the cylinder at low temperatures to insure effective sealing.

Abstract: A throttle valve with a separate flange, usable with a vacuum pump defining an inlet opening, and a controllable throttle assembly for varying a flow passage cross section of the inlet opening. The throttle assembly is disposed in the inlet opening and has a plurality of slats rotatable about respective longitudinal axes for varying their inclination and an actuating rod for turning the slats. The flange has a throughgoing bore through which the actuating rod passes. The slats have a substantially constant width and their longitudinal axes are oriented parallel to one another. The slats form a first and a second slat group, and a linkage connects the slats with one another for turning the slats of the first slat group and the slats of the second slat group in opposite directions. A chamber is situated externally of the inlet opening and communicates with the throughgoing bore. A pivotal lever articulated to the actuating rod is situated in the chamber and projects outwardly therefrom.

Abstract: A two-stage cryosorption pump has a first stage at a higher temperature and a second stage at a lower temperature. Sorption surfaces of reticulated vitreous carbon formed on the second stage have high rigidity and exceptionally high void volume.

Abstract: In a reciprocating pump for cryogenic fluids comprising a pump cylinder in which a piston is oscillatingly displaceable in a sealed state, an inlet valve and an outlet valve, and an annular channel surrounding the pump cylinder on the outer side and forming an outlet for the cryogenic fluid delivered by the pump, in order to attain optimum sealing at the operating temperatures, without the piston motion being impeded at higher temperatures, it is proposed that the cylinder be made of a material with good sliding and self-lubricating properties and a thermal expansion coefficient which is larger than that of the piston, that the dimensions of the cylinder and the piston be so selected that the piston sealingly contacts the inside wall of the cylinder at operating temperature, and that the outlet valve be arranged at the downstream end of the annular channel.

Abstract: A refrigerant fluid trap for a vacuum evaporator for depositing a thin metal film including a U-shaped structure for passage of refrigerant fluid, forming an interior space for trapping condensable vapors. In said interior space there is housed a titanium evaporation source.

Abstract: The refrigerator of a cryopump is positioned within an insulating vacuum and the two stages of the refrigerator are selectively thermally coupled to first and second stage cryopanels. After initial rough pumping by an air ejector, rough pumping is completed during startup by coupling the cold first stage of the refrigerator to a first stage adsorption cryopanel. The second stage of the refrigerator is thereafter coupled to the second stage cryopanel. Thermal coupling of the refrigerator to the cryopanels is by means of spring biased thermal contacts brought into position by movement of the refrigerator. The thermal contact elements are provided with sufficiently large thermal masses to handle the large thermal loads of system startup.

Abstract: The invention relates to a cryopump having a casing (1), a gas inlet opening (8) to which a chamber (30) can be attached through a valve (31), a vacuum pump (18) connected through a valve (16) to the casing, a two-stage refrigerator (4) in the casing as cold source, and pumping surfaces (7, 9, 12, 13) which, on both of the refrigeration stages (5, 11) of the refrigerator, are equipped with an electrical heating means (23, 24). To achieve a great shortening of the time required for regeneration and start-up it is proposed that a sensor (41) be provided to monitor the pressure within the pump casing, and that a control unit (28) be present by which the operation of the cryopump can be monitored and controlled on the basis of the signals supplied by the sensor.

Abstract: A cryogenerator pumping system comprises at least two cryopanels, maintained within an enclosure having an open end which is adapted for attachment to the chamber to be pumped and which embodies a throttling device effective to restrict the flow of gas from the chamber to the cryogenerator pump, a relatively higher temperature cryopanel within the enclosure being arranged to project beyond the plane of the throttling device whereby to be capable of condensing water and other volatile vapors produced in the chamber and thereby prevent the deposition of such vapors upon the throttling device.

Abstract: A high throughput continuous cryopump is provided. The cryopump (10) incorporates an improved method for regenerating the cryopumping surface (22) while the pump is in continuous operation. The regeneration of the cryopumping surface (22) does not thermally cycle the pump, and to this end a small chamber (91) connected to a secondary pumping source (60) serves to contain and exhaust frost removed from the cryopumping surface (22) during such regeneration. The frost is exhausted at a rate substantially independent of the speed of the cryopump which enhances the capability of the pump to achieve a high compression ratio and allow the pump to operate continuously while the cryopumping surface is being regenerated.

Abstract: The pressure relief valve is debris resistant, self-cleaning, and self-actuating in a cryopump. It includes an o-ring carried by a valve member within a valve cylinder. In opening, the valve member moves away from an end port to open vent ports in the side of the valve cylinder while withdrawing the o-ring to a debris free and protected region of the valve. As the valve member is moved into the closed position in response to an atmospherical pressure differential, a wiper ring cleans debris from the inner surface of the valve cylinder. A taper is provided on the inner surface of the cylinder to release compression on the vacuum sealing o-ring upon opening and to compress the o-ring as the valve member moves to the closed position. The wiper ring is expansible in order to provide a wiping action along the entire taper and prevent debris from reaching the o-ring. The end of the valve cylinder opposite to the end port serves as a shock absorber as the valve is opened.

Abstract: A cryopump is regenerated by means of an ejector pump which draws gas from the cryopump as the pump is warmed. The ejector is actuated by an inert gas. The same inert gas may also be used to purge the pump during evacuation.

Abstract: A cryopump with quicker adsorption of non-condensible gases is disclosed. The second stage cryopanel of this cryopump is comprised of an array of discs spaced along an axis perpendicular to the frontal cryopanel, and in close thermal contact with the second stage heat sink. Each disc of the array is bent toward the frontal cryopanel at the outer edge of the disc and is flat radially inward from the bend. Each disc is coated with adsorbent material on the surface away from the frontal cryopanel radially inward from the bend in the disc.

Abstract: A cryogenic pump with a two stages refrigerator, an access grid and condensation walls partially coated by adsorbing material and thermally connected to the second stage of the cryogenic generator, which walls are formed by one or more metallic strips so shaped as to slant considerably in respect to the axis of the cylindrical shield and completely covered by an adsorbing material on both faces; said walls are protected by shielding surfaces at least outside reflecting.

Abstract: To control the temperature of one or more heat sinks of a cryogenic refrigerator in a cryopump, refrigerant gas to the refrigerator is diverted through heat exchangers associated with the refrigerator heat sinks. The diverted refrigerant gas may be used to maintain the temperature of the first stage cryopumping surfaces above some level to avoid cross over hangup. The second stage cryopumping surfaces may be warmed by the diverted refrigerant to some temperature level for partial regeneration. Both heat sinks may be warmed for full regeneration of the cryopump. Bleed flow of refrigerant gas cooled by the first stage of the refrigerator can be directed past a thermal mass to cool that mass. By reversing the flow of refrigerant gas during cooldown of the system, the thermal mass can be used to more rapidly cool the refrigerator. The thermal mass is thermally isolated from the refrigerator heat sinks and is positioned within the vacuum vessel of the cryopump adjacent to the first stage of the refrigerator.

Abstract: A cryopump and a method of operating the same, with the cryopump being provided with a cryopanel adapted to be cooled with cold heat generated by a cold heat generating device, and remove the ambient gas, and a device for regulating the temperature of said cryopanel in accordance with the ambient conditions. The cryopump is capable of varying its pumping speed by regulating in accordance with the ambient conditions the temperature of the cryopanel which is adapted to be cooled with cold heat and remove the ambient gas.

Abstract: An exhaust port from a cryopump vacuum vessel leads to an exhaust valve. The valve is protected from contamination by a filter standpipe which extends from the exhaust port into the vacuum vessel and which is open at its end opposite to the exhaust port. The standpipe is of porous material which allows the free flow of gas, water, and liquid cryogens therethrough while retaining contaminating debris within the vacuum vessel. The filter conduit is of screen formed into a cylinder. One end is tapered and pressed into the exhaust conduit. The screen cylinder is stopped in the exhaust conduit by a circumferential ridge.

Abstract: The cryogenic pump operates in two stages, utilizing a supercharging part and a high pressure part. These two parts are comprised of a high pressure piston pump (3, 4, 34, 35) and a supercharger (5, 6, 61, 62) disposed in a tandem relationship and sharing a common piston rod (8). The supercharger is enclosed in a heat insulated intermediate container (7) and delivers the liquid cryogenic fluid to the high pressure cylinder. The pump operates to convey a liquid cryogenic fluid such as liquid nitrogen, for example, at a high pressure through evaporating means into pressure resistant commercial steel cylinders where the gaseous nitrogen is kept at a pressure of 200 bar and ambient temperature.

Abstract: A cryopump has a two-stage refrigerator in a housing with a pumping surface area in thermal communication with each stage of the refrigerator for gas-pumping by adsorption or absorption when the refrigerator is operated. A roughing vacuum pump provides a pressure of from about 1 to about 10.sup.-3 mbar to the housing and at least the pumping surface area of the second refrigerator stage is heated sufficiently to prevent gas adsorption or absorption thereon before the cryopump is operatively connected to a space to be evacuated therewith as a starting method for improving the cryopumping of, particularly, helium and a regenerating method after use of the cryopump.

Abstract: Orifices in a cooled plate throttle gases entering a cryopump. Selected orifices are closed by removable closures such as spring clips to allow the throttling to be varied.

Abstract: A vacuum cooling trap for use in a vacuum chamber comprising: a laminated structure comprised of a pair of plates bonded together in face-to-face contacting relation, the plates being composed of metal of high thermal conductivity, and the plates having aligned confronting conduit portions which jointly define a conduit within the laminated structure for circulating a cooling medium through the laminated structure during use of the vacuum cooling trap.

Abstract: A cryosorption pump for high vacuum condition to be evacuated generally comprises a cryopumping container connected to a chamber to be evacuated, and cryosorption and cryocondensation members located in the container. The cryocondensation member surrounds the cryosorption member on which an adsorbent is applied to adsorb gases which are not beforehand condensed on the cryocondensation member. A coil means or magnet means for generating a magnetic field is also disposed in the container so as to generate a magnetic field around the cryosorption member to prevent from the impingement of energetic electrons or .beta.-rays emitted from a material condensed on the cryocondensation member against the cryosorption member.

Abstract: A reactor for performing reactions at very low, i.e. cryogenic temperatures has a collection vessel mounted above an electron gun to collect vaporized material such as metals, metal oxides, metal salts and metal halides. The collection vessel is maintained at a very low temperature, typically between 14.degree. and 77.degree. K., by a heat pump that also serves as a support for the collection vessel. A manifold introduces a reagent into the reactor between the electron gun and the vessel to react with the vaporized material and form a product. The product is condensed on the collection vessel which may then be inverted to provide a stable support for the collected product during further experimentation.

Abstract: A cryopump and method for using cryopumping to enhance the sensitivity of a leak detection system. The cryopump is used to control the relative pumping speeds of the gases normally frozen out on the pump or adsorbed in a cold adsorbent to thereby achieve the enhanced sensitivity of the system. The system is characterized by controlled access to the cold panel which is disposed within the warm panel.

Abstract: Hydrogen is stored at cryogenic temperatures by adsorption on porous carbon having a nitrogen BET apparent surface area above about 1500 m.sup.2 /g. Hydrogen can be adsorbed and desorbed in the context of a cryopump, having as the pumping element a panel, having large particles of pressed porous carbon thereon.

Abstract: An oil free vacuum system 10 which comprises a high thermal capacitance cryopump 12 and air ejector 38. The air ejector 38 is used to reduce load lock chamber 16 pressure to an intermediate vacuum. Cryopump 12 further evacuates chamber 12 to the operating vacuum of a work chamber 14. The work chamber 14 is maintained at high vacuum by a main cryopump 20. The main cryopump can be started in an oil free manner through the use of air ejector 38 and high thermal capacitance cryopump 12. A high themal capacitance, high thermal conductance cryopanel is formed of a lead/copper sandwich.

Abstract: An improved cryopumping apparatus which comprises a cryopumping space which may be alternately opened and closed from the surrounding area by moveable panels, trubular cryopanels within said cryopumping space through which a coolant such as liquid helium may be passed, and an apparatus for spraying liquid argon onto said cylindrical cryopanels in order to enhance the cryogenic entrapment of such low-z ions, atoms, and molecules as hydrogen and helium.

Abstract: A pump for compressing a low temperature high density liquid gas, e.g. liquid helium, wherein the piston is driven by a motor through a four bar linkage which converts rotary motion to reciprocating motion. The pump also includes an improved piston ring assembly, piston venting apparatus and a cushioned discharge valve. A two-stage pump in combination with support equipment provides an improved pumping cycle wherein low temperature density liquid or gas e.g. liquid helium can be withdrawn from a storage reservoir, vaporized and compressed into cylinders.

Abstract: A second stage cryopanel array suitable for both concentric refrigerators and side entry cryopumps is formed of two groups of semi-circular baffles mounted to respective L-shaped brackets. The array sections can be independently positioned about a second stage of a refrigerator.

Abstract: In a cryopump, condensation of gases such as argon, oxygen and nitrogen on surfaces other than the second stage array 38, 40 is avoided to prevent cross over hang up and pressure instability. To prevent condensation of argon, oxygen and nitrogen on the frontal cryopumping array 46, that array is held to a temperature of at least 50.degree. K. A heat load to the first stage increases as the temperature of the first stage drops. That heat load is provided by a high emissivity radiation shield 44 or by a thermal switch 56, 58. Condensation of argon and other gases on the second stage refrigerator cylinder 32 is avoided by a close fitting sleeve 52 positioned over the refrigerator cylinder 32 in thermal contact with the second stage heat sink 30 but out of thermal contact with the cylinder 32.

Abstract: A vibration isolator is disclosed to mount a cryopump expander module or other vibrating equipment on a vacuum housing. The isolator includes a welded metal bellows which both forms a vacuum-tight passage and acts as an isolating spring, and a plurality of elastomeric isolators which clamp the oscillations of the bellows.

Abstract: A low-temperature pump having a throttling valve formed by tilting radially disposed vanes in side-by-side relation, capable of fully opening a pump port to a process chamber. Motion from one vane can be coupled to the next through shims which support the vanes and form a seal when the vanes are flat in a common plane. One of the vanes may be controlled independently of the others so that coarse and fine modes of operation may be achieved by separately controlling (N-1) vanes and the Nth vane. The vanes are maintained in thermal contact with a chilled outer wall surface of a first pumping stage of a two-stage pump, the second stage coaxially surrounding a first stage maintained at a very low temperature. A central hub, at the convergence region for the vanes, supports a shield, protecting the second stage from radiation through a port in the upper regions of the pump.

Abstract: A cryopump of vertically tiered individual generally conical shaped sections with linearly increasing base diameters arranged smaller to larger base diameter as the distance increases from the coldest end of elongated refrigeration source. Individual cryopanels are a surface of revolution with tapered bayonet joint interlocking portions to permit ease of assembly while maintaining good thermal contact between sections.

Abstract: A cryopump 20 with increased adsorptive capacity comprising a honeycomb adsorption structure 46 positioned within a second stage chevron assembly 40. Multiple chambers 58 of the honeycomb are covered with adsorbent charcoal 68. The entire structure 46 is attached to a second stage 52 of a cryogenic refrigerator 45.

Abstract: To reduce the time for regenerating self-contained cryopumps a direct connection is provided during the defrosting operation between the associated expansion space and the high-pressure gas source of the cryogenerator, to heat up the low-temperature condensation surface, while the cryogenerator continues to operate. The application is particularly to multi-stage self-contained cryopumps.

Abstract: A liquefied gas transfer apparatus having a recirculation passage for recirculating the liquefied gas sucked into a glandless pump back into the closed tank, and a device for changing the speed of the pump driving motor by suitable measures such as pole change, Y-.DELTA. switching, frequency control, primary voltage control or the like. In operation, the pump is driven at a high speed during the transfer of the liquefied gas from the tank to the containers or the like, whereas, in the period in which the transfer of the gas in not necessary, the pump is continuously operated at a low speed while recirculating the liquefied gas through the recirculation passage, thereby to prevent the evaporation of the liquefied gas in the pump to ensure smooth and safe intermittent operation of the pump, as well as prolonged life of the bearing.

Abstract: Apparatus for pumping gas continuously a plurality of articulated panels of getter material, each of which absorbs gases on one side while another of its sides is simultaneously reactivated in a zone isolated by the panels themselves from a working space being pumped.

Abstract: A cryopump having two refrigerator stages operable for producing progressively lower temperatures and at least one surface between the refrigerator stages and in such thermal communication therewith as to have, during operation of the refrigerator stages, temperatures which adsorb and desorb thereon at least one gas in the cryopump, having the improvement comprising:shield means extending over substantially all of the surface for substantially preventing the gas from circulating to the surface; andmeans for maintaining the shield means at a substantially constant temperature during operation of the refrigerator stages.

Abstract: Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.

Abstract: A cryogenic storage tank with a built-in pump for pumping cryogen directly from the primary storage container consistent with low boil-off losses of cryogen has an outer vessel, an inner vessel and an evacuated insulation space therebetween. A pump mounting tube assembly extends into the interior of the inner vessel and includes an inner pump mounting tube and an outer pump mounting tube joined at their lower rims to define an insulating jacket between the two tubes. The inner pump mounting tube is affixed at its upper end to the outer vessel while the outer pump mounting tube is affixed at its upper end to the inner vessel. The inner pump mounting tube defines a relatively long heat path into the cryogenic container and is itself insulated from the liquid cryogen by a pocket of trapped gas formed within the inner pump mounting tube by heated cryogen.