Abstract: Plasma torch with an integrated electrode incorporating many heat pipes each heat pipe comprises an evaporating section and a condensing section set at a front end and a rear end of the electrode, respectively. The heat pipes with extremely high thermal conductivity can be used to replace the traditional water-cooled torch's electrode. The effect of reducing the elevated temperature at the torch's arc root zone through cooling by heat pipes is beneficial for prolonging the lifetime of plasma torch. Each heat pipe is filled with a small amount of working fluid. Even if one heat pipe is etched out, the cooling liquid thus ejected is limited without causing gas explosion and rock curing; the rest of heat pipes are not damage and can still function; although the heat dissipation efficiency might be reduced a little, the plasma torch still works. Thus, flexibility of the whole heat dissipation is enhanced.

Abstract: Nanomechanical, nanoelectromechanical, and other molecular-scale pump assemblies are described. In certain embodiments, the pump assembly includes a cavity. The cavity includes a plurality of nanofilaments, a surface proximate at least one of the nanofilaments, a fluid flow path, and an opening. Molecules of a fluid that flows from the opening through the cavity along the fluid flow path collide with the surface or one or more of the nanofilaments such that the molecules are accelerated along the fluid flow path. A molecular-scale pump assembly includes a plate defining a plurality of openings, and a plurality of cantilevered molecular-scale beams positioned over each opening. In certain embodiments, molecules of a fluid are accelerated through the opening by asymmetric oscillation and in other embodiments charges are guided along a conductive channel by asymmetric collisions.

Abstract: Provided is an oil diffusion pump equipped with an oil vapor generator capable of eliminating the problems occurring when a heater wire is used as a heating source for an operating oil. The present invention is a vacuum pump for which an oil vapor generator (70) is arranged within a casing (51) and this oil vapor generator is operated to vaporize an operating oil (8), thereby producing oil vapor and this oil vapor is sprayed from a jet (53, 53a) to exhaust intake air. The oil vapor generator (70) is equipped with: a container (71, 72) in the interior of which oil is stored, with the lower end of the tubular member (71), which comprises a material to be heated, being closed; and induction coil (75) wrapped around the atmosphere-side perimeter of the tubular member (71) (in particular, the case inner wall (71b)) with an insulating material (73) therebetween; and a power supply means that applies a low-frequency alternating current of several tens of Hz to several hundreds of Hz to the induction coil (75).

Abstract: An electrospray diffusion pump with an upper vacuum chamber coupled to a lower vacuum chamber by a cylinder having an aperture in the upper chamber at the center of a conductive extractor ring. A conductive tube is positioned in the upper chamber and is axially aligned with the conductive extractor ring. The conductive tube is coupled to receive a conductive or semi-conductive spray fluid. A voltage source is coupled between the conductive tube and the extractor ring and adjusted to form a Taylor Cone that provides a jet of charged droplets at the tip of the conductive tube, the charged droplets are attracted to the extractor ring and pass into the aperture, then through the cylinder into the second chamber. The charged droplets have nearly zero vapor pressure and transfer ambient gas at a first pressure from the upper chamber to the lower chamber at a lower pressure.

Abstract: A vapor jet vacuum pump includes a housing having an inlet port and a foreline conduit, a vapor jet assembly within the housing, a vapor source for supplying a vapor to the vapor jet assembly, and at least one ejector stage. The ejector stage includes an ejector nozzle mounted in the foreline conduit and a fluid inlet located external to the housing and coupled by an ejector conduit to the ejector nozzle. The fluid inlet may be an air inlet for drawing in air at atmospheric pressure. The ejector stage may be driven by a backing pump coupled to the foreline conduit.

Abstract: A housing that defines a high vacuum work environment includes a monolithic member that has one side having a baffle region and a wall region. The baffle region includes at least one angularly contoured evacuation opening that forms a zig-zag flow path from the high vacuum work environment. In the preferred embodiment, each evacuation opening has a chevron-shaped cross section having an outer channel portion that is defined by baffle fins that are parallel or substantially parallel to each other, but at an acute angle relative to the side of the monolithic member. The wall region includes convection cooling fins that are aligned with the baffle fins.

Abstract: A high vacua diffusion pump for use in a vacuum system including a chamber to be evacuated and a positive displacement pump. The diffusion pump includes a pump body structure having an open upper end and a closed lower end. A boiler and jet assembly is yieldably supported within the pump body and produces jet streams that impel the residual air molecules through the exit port. A ceramic heat break having a labyrinth passage therethrough positively separates the temperature of the condensing wall surface from the boiler temperature. A cooling system permits selective rapid cooling of the boiler and is openable to permit rapid re-heating of the boiler. In one embodiment, the pump includes a room temperature condensing surface, and in another embodiment a non-room temperature condensing surface is provided.

Abstract: A counterflow helium mass spectrometer leak detector in which a helium sample passes in a reverse direction through a diffusion pump to a mass spectrometer for measurement. The diffusion pump includes a conventional foreline and a second foreline provided with an ejector stage. A test sample is coupled from a test port through a bypass valve to the conventional foreline in a high sensitivity mode and is coupled to the second foreline in a low sensitivity mode. In the low sensitivity mode, the bypass valve is closed. An apertured control plate in the diffusion pump controls the relative reverse rates of duffusion from each foreline to the diffusion pump inlet by controlling the rates of vapor flow an annular pumping stages and to the ejector stage. The ejector stage includes a nozzle for directing a stream of vapor into the second foreline so as to inhibit flow of helium into the diffusion pump and establish a lower reverse diffusion rate at the second foreline.

Abstract: A control system for a diffusion pump is provided which serves to protect the pump from loss of the pumping fluid, from loss of water cooling, as well as from overheating of the heater. The protective system includes a thermally responsive switch mounted on a heat-conductive bracket, and which responds to the temperature of the cooling water as well as to heat radiated from the heater to turn off the electric current to the heater when either the temperature of the cooling water or the heat radiated from the heater rises above a predetermined value. The control system also includes a heater block surrounding the heater, and which is composed of a material having a relatively low melting point as compared with the melting point of the material forming the containment vessel of the pump, so that overheating of the heater will cause the block to melt and to be displaced from the bottom of the containment vessel to reduce heat transfer to the pump.

Abstract: A diffusion pump is operated by controlling the rate at which vapor is evaporated from a pool in response to an indication of the effectiveness of a fluid in cooling a condensation surface for the vapor as derived by sensors for the temperatures of the pool and along a temperature gradient from the pool to a cooling coil for the condensation surface. When the sensors indicate that the vapor is not effectively cooling the surface, liquid is vaporized from the pool, but at a slower rate than when the fluid is effective in cooling the surface. To increase the life of a brass strap on the temperature gradient, opposite ends of the strap are connected to a cooling coil for the condensation surface and a stainless steel block connected to a well in which is located an electric heater for vaporizing the oil from the pool.

Abstract: A diffusion pump for a leak detector of helium or other light gases includes a foreline, responsive to gases from vacuum equipment being monitored for leak detection, and an inlet, connected to a mass spectrometer or other similar high vacuum gas measuring instrument. The diffusion pump includes two diffusion stages. The second stage has a diffuser throat with a relatively narrow width and small cross-sectional area so that the velocity of diffusion oil vapor flowing through it causes the light gases to be easily back diffused from the foreline to the inlet, while substantially preventing the flow of air or other relatively heavy gases between the foreline and the inlet. Fluid is returned to the pool by a conduit having a vertically extending, longitudinal axis aligned substantially with the center of the pool and an outlet orifice in proximity to the bottom of the pool, whereby the oil is returned to the coolest part of the pool at its bottom, central portion.

Abstract: A diffusion pump includes a flat metal boiler plate having an upper face defining a floor for a pool of a vaporizable diffusion pump fluid or oil and a lower face against which the metallic sheath of a tubular electric heater is pressed by a coextensive massive clamping plate. The heater has a tendency to be overheated if only air is its thermal load. To prevent overheating of the heater because of variations in the geometry of the heater sheath which tend to cause air spaces between the sheath and the face of the boiler plate, a thin flexible metal crush plate is disposed between the clamping plate and the heater. The crush plate has a plurality of spaced, raised dimples adapted to contact many portions of the heater sheath throughout the length of the sheath. As the clamping plate, the flexible plate and the heater are urged toward the boiler plate by nut and bolt assemblies securing the clamping plate to the boiler plate, the dimples are deformed whenever they are in contact with the heater sheath.

Abstract: An improved vacuum diffusion pump is shown. The pump consists of the conventional elements of a pump body with inlet and outlet ports, a vaporizer, a vapor jet assembly such as a vapor chimney within the pump body and cooling means associated with the outer walls of the pump body. A fan is positioned between the top of the vapor chimney and the inlet port of the diffusion pump. When rotated, the fan drives oil vapors "backstreaming" from the pump body downwardly into and against the walls of the pump body. The fan may be driven by external means but preferably is driven by a turbine positioned in or near the vapor chimney and attached to either an axial shaft supported within the chimney or directly to the fan itself. The turbine is driven by the fast moving oil vapors and in turn drives the shaft.

Abstract: A thin-film deposition apparatus comprises a cabinet having a vessel mounted therein which defines a vacuum chamber adapted to retain processed articles. A vacuum unit is mounted adjacent to the vessel to communicate in substantially unrestricted communication with an inlet opening to the vacuum chamber for selectively evacuating the same. A valve is reciprocally mounted in a chamber communicating with the inlet opening to selectively expose the inlet opening during the evacuation process. A plurality of water-cooled and V-shaped baffles or a primary trap is mounted between the piston and the vacuum unit to provide an optically dense view of the vacuum chamber from the downstream side of the trap and to trap contaminants, such as oil droplets, prior to their ingress into the vacuum chamber from the vacuum unit. In addition, a plurality of fins or a secondary trap is mounted in nesting relationship within the baffles to provide an optically dense view of the primary trap from the vacuum chamber side thereof.

Abstract: A diffusion pump capable of separating impurities from its pump fluid during operation is disclosed. Skimming drains are provided in the pump's boiler for periodically skimming the evaporative surface of the working fluid. This eliminates nearly all contaminants of higher molecular weight than the pump fluid. In the foreline of the pump, a series of peripheral gutters are provided for trapping, separating and draining off condensates. The gutters facilitate the removal of impurities of lower molecular weight than that of the pump fluid. Means are also provided for further removing trace quantities of residual volatile impurities which tend to backstream up the diffusion pump barrel. The highly purified pump fluid allows for a more vigorously working evaporative surface, thereby increasing the throughput of the diffusion pump. Together with the elimination of volatile impurities from the pump barrel, this facilitates the attainment of significantly higher ultimate chamber vacuum.

Abstract: A predetermined pressure ratio is maintained between a foreline and a load port of a vacuum diffusion pump including a bath of oil that is vaporized by a heater. A property of the pump is sensed to derive a signal indicative of the pressure ratio. The signal is compared with a set point value to derive an error signal that controls the amount of power continuously supplied by the heater to the oil bath. The sensed property can be the RMS power supplied by the heater, the heat supplied to the bath, or the density of vaporized fluid in the pump.

Abstract: A diffusion pump capable of separating impurities from its pump fluid during operation is disclosed. Skimming drains are provided in the pump's boiler for periodically skimming the evaporative surface of the working fluid. This eliminates nearly all contaminants of higher molecular weight than the pump fluid. In the foreline of the pump, a series of peripheral gutters are provided for trapping, separating and draining off condensates. The gutters facilitate the removal of impurities of lower molecular weight than that of the pump fluid. Means are also provided for further removing trace quantities of residual volatile impurities which tend to backstream up the diffusion pump barrel. The highly purified pump fluid allows for a more vigorously working evaporative surface, thereby increasing the throughput of the diffusion pump. Together with the elimination of volatile impurities from the pump barrel, this facilitates the attainment of significantly higher ultimate chamber vacuum.

Abstract: A diffusion pump, particularly adapted to pump light gases at a constant rate, includes a flow path for condensate from a cool wall of a body assembly to a region substantially in the center of a liquid pool of vaporizable diffusion pump liquid. Heat to vaporize the liquid in the pool is applied to a peripheral side wall of the pool so that vapor rises from the periphery of the pool to a jet assembly, from which the vapor is emitted through nozzles against the cool wall. The jet and body assemblies are mounted on a shelf above the surface of the pool and are substantially thermally isolated from a heat source for the pool. A fore line includes a plurality of baffle plates that are substantially thermally isolated from the cool wall by a vacuum space. The baffle plates are warm enough to boil away substantially all high vapor pressure materials contacting them, yet cool enough to condense the diffusion pump fluid vapor that contacts them, whereby the condensed vapors in the fore line flow back to the pool.

Abstract: A vacuum diffusion pump includes a body assembly fabricated from a single piece of deep drawn sheet metal whereby a cylindrical wall of the body assembly, a flange for connecting the diffusion pump to a vacuum chamber, and a floor for a pool of diffusion pump fluid are all formed from the single piece of sheet metal. A boiler for heating the fluid to a vapor includes a cylindrical heating surface centrally located in the pool and extending axially from the bottom surface of the pool. The heating surface is surrounded by a separator tube having openings close to the bottom of the pool so that liquid in the pool enters an annular space between the separator and heating surface close to the bottom of the pool and rises in the annular space while being heated to vaporization. A solid heat insulator is located in another annular space between a cup and the exterior of a segment of the body wall that confines the pool and the exterior of the floor.

Abstract: A diffusion pump is provided in which an internal vacuum chamber is surrounded by regions of the pump through which working vapors flow. This configuration enables a single heating unit to heat both the working fluid of the pump and the vacuum chamber.In certain embodiments, a differential pump is provided in which a common boiler provides working fluid for a pair of pumping sections, each of which evacuates a different vacuum chamber. Application of this pump to a gas chromatograph/mass spectrometer system permits operation with relatively large gas throughput while maintaining a relatively low pressure chamber for the mass spectrometer ion source and a much lower pressure chamber for the mass analyzer.