Abstract: A laser system support structure is provided having an independent, kinematically mounted chamber and optics platform. Swivel-type mounts are used to couple the platform at three points to the laser support frame, thereby allowing the platform to remain static while the support frame, via the swivel mounts, deflects around the platform in response to external forces. The independent platform design provides secondary benefits of creating a compartmentalization of laser system components, leading to a modular type design. Each laser system module is mounted to the support structure on an extension rail, to allow removal of the module from the support frame for easy access during servicing.

Abstract: An anode and an a cathode in a gas laser, such as an excimer laser, are spaced in a first direction. A voltage difference between these members produces an electrical discharge which ionizes gasses in the laser to react chemically and produce coherent radiation. First and second tubes made from a dielectric material are designed in contradiction to conventional designs by utilizing a constant, larger tube diameter with thicker tube walls. These first and second tubes extend through the laser in a second direction transverse (preferably perpendicular) to the first direction. The anode, the cathode and the tubes extend through the laser in a direction transverse to the first and second directions. The use of a thicker walled, large tube of constant diameter allows the use of a commercial grade polycrystalline aluminum oxide ceramic, rather than ultra pure ceramics.

Abstract: An external control system for a laser system, used as an illumination source for a stepper system, is provided. The external control allows for a measuring of the energy actually distributed to a wafer and a correction of the energy dose distribution based upon this measurement. In this way, a more precise energy dose control is achieved. The external control communicates with the laser's own internal control system to provide serial inputs which allow for corrections to be made to the High Voltage setting based upon the aforementioned measurements, and coordinates with the laser's internal control system to initiate laser operation at the required intervals.

Abstract: A diagnostic sub-routine for use by the control system of a gas discharge laser is disclosed. The sub-routine provides a prediction of the time remaining, based upon real-time laser system operations, for each pulse-limited sub-system within the laser. The sub-routine utilizes a calculated average pulse repetition rate over a user-defined time interval as the basis for predicting the time remaining, under current operating conditions, until the end-of-life for each pulse-limited sub-system; and continually updates the time prediction to account for changes in the lasers operation. The predicted time is reported to the operator to allow advanced scheduling of routine maintenance.

Abstract: A shutter mechanism having a slide element coupled to a support base by a plurality of roller bearings journaled between opposing pairs of guide rods is disclosed. The slide element and support base have corresponding beam apertures in alignment when the shutter is in its open position. Angularly mounted on the slide, adjacent to the slide's beam aperture, is a UV reflective mirror. When the shutter is commended to close, an actuator forces the slide and support base apertures out of alignment, while simultaneously positioning the UV reflective mirror into the position previously occupied by the slide's aperture. A laser beam, previously being transmitted through the aligned apertures, will be reflected by the mirror to a beam stop as a diagnostic instrument mounted on the support base.

Abstract: A housing in a laser system encloses a cathode and a displaced anode and gases ionizable and reactive chemically when a voltage pulse produces a cathode-anode electrical discharge. Moving air cools the components (capacitors, thyratron and triggering circuitry) for producing the voltage pulses. The laser gas temperature is continuously regulated at a particular value whether or not there is an electrical discharge. The concentration of one of the gases in the chamber is regulated to values alternately on opposite sides of an optimal value to provide an optimal energy in each chemical reaction of the gases. The gases are recirculated as by a fan driven on a shaft by a pair of motors and are filtered during such recirculation. The shaft speed is regulated at a particular value and the motor currents are regulated to be equal. Any ozone formed in a compartment holding the high voltage terminals is purged by passing a neutral gas (nitrogen) through the compartment to the atmosphere.

Abstract: An X-ray tube rotating anode is cooled with a liquid metal functioning as a recirculated heat exchange fluid and/or a metal film in a gap between the anode and a stationary structure. The liquid metal is confined to the gap by (a) a labyrinth having a coating that is not wetted by the liquid, (b) a magnetic structure, or (c) a wick. The liquid metal recirculated through the anode is cooled in a heat exchanger located either outside the tube or in the tube so it is surrounded by the anode. The heat exchanger in the tube includes a mass of metal in thermal contact with the recirculating liquid metal and including numerous passages for a cooling fluid, e.g. water. A high thermal conductivity path is provided between an anode region bombarded by electrons and a central region of the tube where heat is extracted.

Abstract: An improved gas pressure gauge is disclosed that extends the linear range of pressure dependent damping to higher pressures by placing a stationary member in very close proximity to the vibrating member. This range of linear dependent damping is also extended to lower pressures by making the vibrating member large in area relative to its small distance from a fixed planar member, which can also serve as its supporting member, by making it vibrate in a direction perpendicular to the fixed planar member, and by making the springs that support the vibrating member from a high Q and conductive material, such as boron doped single crystal silicon. These features for extending the range to higher and lower pressures can be built separately into two independent vibrating elements that can be used individually or in tandem, or they can be built into a single vibrating element that can be made to vibrate in two modes, one parallel and one perpendicular to a fixed member.

Abstract: Apparatus equipped for both megavoltage radiotherapy and a diagnostic X-ray source for portal imaging. Both the high energy therapeutic and low energy diagnostic source of radiation are physically located at the same point in apparatus space, and utilize a single moveable target converter that is physically positioned according to the desired use, either therapy or diagnostics.

Abstract: The present invention refers to a pumping stage particularly designed for turbomolecular pumps, having increased compression ratio, and capable of extending the operating range of the turbomolecular pump towards high pressure. The new pumping stage comprises a casing housing, a rotor disk, and a substantially coplanar stator ring. The stator ring consists of two plates connected with each other along their circumferential periphery, thereby defining a region of close tolerance with the opposite surfaces of the rotor. The rotor and stator cooperate to define a tapered, free annular channel having a suction port and a discharge port at the opposite ends of this channel. The channel tapers in a functional, predetermined fashion, having the largest cross-sectional area near the suction port, and converging, according to the rotational direction of the rotor, at the discharge port.

Abstract: The present invention relates to turbomolecular pumps comprising one or more tangential flow pumping stages in addition to axial flow pumping stages, so as to raise the pump exhaust pressure up to the atmospheric pressure, wherein at least one tangential flow pumping stage having a tangential flow pumping channel of improved design. The channel is located between the lateral surface of the rotor disk and the annular inner wall of stator and comprises an upper closure plate provided with suction port and a lower closure plate provided with diskharge port wherein these ports operably coupled to the tangential flow pumping channel. The cross-section area of the channel is enlarged from its periphery portion defined by the lateral surface of the rotor disk to a central portion defined by the upper and lower closure plates.

Abstract: The present invention refers to a pumping stage for turbomolecular pumps comprising a rotor disk (3), integral with a rotating shaft (4) operated by a motor, and a stator disk (1) said stator disk (1), integral with the pump body (2), where the stator disk (1) is a disk whose surface is substantially smooth that can assume, during the evacuation cycle, a bladed configuration, by raising radial sections (5) of the disk surface itself. Raising of radial sections (5) is performed by at least one actuator device (11) controlled, through an electronic control device (12), by a pressure sensor (13) sampling the pressure inside the pump body (2).

Abstract: An electronic braking device is provided for an asynchronous motor equipped with magnetic bearings of a type used in turbomolecular pumps. The device comprises a circuit for recovering the kinetic energy of the rotor as it decelerates as a result of a disruption of electric current from an external power means. The device is adapted to convert the rotational kinetic energy of the rotor to an electric current and in order to maintain the support provided by the magnetic bearings.

Abstract: A PPM coupled-cavity traveling wave tube has an RF structure comprising a re-entrant double-staggered ladder circuit. Several cavities are separated by iron pole pieces with penetrating slots to provide RF coupling between the cavities. Re-entrant copper bars are attached to both sides of the pole pieces that define the boundaries between adjacent pairs of cavities. These bars extend diametrically across the cavity interior around beam drift tubes The re-entrant bars on adjacent pole pieces are rotated relative to each other by 90 degrees about the beam axis. The bars are hollow along their length, and thereby provide channels for coolant flow around the drift tubes. These channels communicate through apertures with coolant distribution channels in the outer cavity walls extending along the length of the traveling-wave tube.

Abstract: Disclosed is an invention for optimizing recovery of petroleum from a subterranean, petroleum containing formation by improving the efficiency of a steam drive through a linear heat reduction schedule and a partial shut-in of the producing well after steam breakthrough. The linear heat reduction schedule and the partial shut-in to compensate for steam override results in maximized discounted net oil recovery with optimal utilization of steam generation capacity.

Abstract: A borehole televiewer is modified to provide an improved signal-to-noise ratio by utilizing a series of receivers arranged in a planar array configuration with respect to a centrally located transmitting transducer. The array covers at least a 90.degree. quadrant of the tool, extending approximately 45.degree. on either side of the transducer to allow the receivers to capture all primarily reflected signals, both the specular component as well as the vertical and horizontal components of the scattered reflections. The signal-to-noise ratio is further enhanced by the use of a noise-dependent timing means, as well as signal conditioning and detection circuits for each of the receivers in the array.

Abstract: A method and apparatus is described for determining petrophysical properties of porous media by the use of light transmission through the media. Specifically, by using a highly collimated light source, preferably a laser, the permeability, grain size, wettability, porosity and clay swelling behavior of a sample can be determined on the scale of millimeters. A calibration curve or function is first established to correlate light transmission through a slab of sandstone on the order of 5 to 10 mm under known conditions. This curved is then used to determine unknown conditions by measuring light transmission and comparing the values to those on the curve. Other applications for the phenomenon of light transmission through porous media are disclosed whereby conditions in a flowing stream of liquid can be monitored by use of light transmission. Specifically, changes in the refractive index and immiscible contamination can be detected.

Abstract: Recovery of viscous petroleum such as from tar sands is assisted using a controlled flow of hot fluid and hydrogen-generating gas in a flow path within the formation; thus a solid-wall hollow tubular member in the formation is used for conducting hot fluid to promote hydrogenation in conjunction with a hydrogen-generating gas and reduce viscosity of the petroleum to develop a potential passage in the formation outside the tubular member into which a drive fluid is injected to promote movement of the petroleum to a production position.

Abstract: A method is disclosed for fluid injection and oil production from a single wellbore which includes providing a path of communication between the injection and production zones.

Abstract: A method of heating produced fluid in a wellbore having multiple tubing strings. In the portion of the wellbore above the dual-string packer a portion of hot injection fluid is selectively flowed from the injection tubing string into the casing annulus where the production tubing is heated, and the flowing viscosity of fluids therein is lowered.