Abstract: An X-ray generating apparatus is provided with a unitary vacuum enclosure having a rotating anode target and a cathode assembly for generating X-rays transmitted through an X-ray window. The cathode assembly is placed within the vacuum enclosure through an opening in the top wall thereof, and comprises a disk which completely covers this opening. The unitary vacuum enclosure and the disk form a radiation shield. For increasing a thermal capacity of the unitary vacuum enclosure and installing the X-ray generating apparatus into a gantry it further comprises a mounting block which may be coupled to or encompass the unitary vacuum enclosure. The X-ray window is placed within the mounting block. A window adaptor may be utilized for the X-ray window installation.

Abstract: A current mode analog signal multiplexor includes multiple input multiplexed differential amplifiers, and an output differential current amplifier. An input multiplex control signal selects and enables one of the input multiplexed differential amplifiers for buffering and steering the input signal current to one side of the output differential current amplifier. The reference amplifier drives the other side of the output differential current amplifier. The output node of the output differential current amplifier remains at a substantially constant voltage potential while providing an output current which varies in relation to the selected input signal.

Abstract: A rotating sealing device for sealing between a wall separating two mediums under substantially different pressure and a rotatable shaft utilizes a combination of a liquid meatal seal comprising at least one liquid metal ring and a shield means which prevents contamination of the metal ring by gases coming into contact with the liquid metal. Magnetic fluid seal, a ring of an oil material, or inert gas may be used as a shield to protect the liquid metal.

Abstract: A fluid thermal mass flow meter including a composite flow tube having four tubular segments of high thermal conductivity formed in a length of tube made of a material having a relatively low thermal conductivity, a thin film element formed on the surface of and extending around each of the four tubular segments, circuitry for incorporating the elements into a bridge circuit, and a housing for containing the flow tube, elements, and circuitry.

Abstract: A method of operating a quadrupole ion trap as a mass spectrometer, in which the ion mass to be detected is selected by adjusting the three dimensional quadrupole storage field to make the .beta..sub.z value of the selected mass equal to a fixed, predetermined .beta..sub.z value of a narrow range of frequencies excluded from a broadband supplemental RF electric field. The ions are detected to provide a signal corresponding to the amount of the selected ion mass.

Abstract: An improved process for forming titanium silicide layers on semiconductor device silicon regions which have native oxide thereon utilizes a reactively sputter deposited layer of TiH.sub.x.ltoreq.2 followed by a rapid thermal anneal in a nitrogen bearing gas. This process results in lowered silicidation activation energy and lower anneal temperature requirements. Production throughput is improved with respect to prior art methods of removing the native oxide or minimizing its negative effect on silicide formation. The same process produces a titanium nitride/titanium silicide bilayer on silicon, and a titanium nitride/titanium bilayer on silicon dioxide. The thickness of the titanium nitride layer over silicon dioxide is enhanced by the use of TiH.sub.x.ltoreq.2 in place of Ti layers used in prior art, thus improving the utility of the titanium nitride as a diffusion barrier layer.

Abstract: The present invention is an improved modular cooling device for cooling gas chromatography analyte sample injectors. The invention is embodied in a series of tubes connected in fluid communication from a coolant supply valve to the injector heating block. A flexible supply tube capable of carrying coolant while maintaining structural integrity at temperatures up to about 150.degree. C., and having a low thermal conductivity is connected in fluid connection with a coolant supply at one end, and a transition tube at the other. A transition tube, in fluid communication with the supply tube at one end and with the cooling tube at the other, is selected to maintain structural integrity at temperatures up to 450.degree. C. and to have a low thermal conductivity. The cooling tube is in fluid communication with the transition tube at a receiving end and with an exhaust at an exhaust end, and has an outer surface that is physically engageable with a surface of the heating block.

Abstract: A radiotherapy couch top has a frame and preferably a pair of beams extending parallel to each other, capable independently of moving towards or away from each other while keeping their mutually parallel longitudinal direction. For supporting the beams in this way, at least two linear slide bearing ways are provided, extending parallel to each other in a transverse direction perpendicular to the beams, at least one of them being supported by the frame. A pair of riding blocks are on each of these linear slide bearing ways, each supporting a corresponding one of the beams and slidable along the linear slide bearing way. Panels are placed over the beams, including one attached to the frame and another which is removable. The removable panel may be replaced with another having an open window section provided with a grid of carbon fiber stringing capable of supporting the patient and allowing projection of radiation directly onto the patient's skin.

Abstract: An X-ray tube has an anode and a photocathode inside a vacuum envelope and an electron multiplier is disposed between them. Such an electron multiplier may be a plurality of sequentially disposed dynodes or a microchannel plate. Because of the secondary electron emission from such an electron multiplier, a higher-power radiation is obtained without requiring a high optical power level to generate photoelectrons. The vacuum envelope may be of a rotary type with the anode and photocathode having annular regions.

Abstract: Radiation damping effects in NMR are compensated by splitting the amplified NMR signal induced in the main probe coil to obtain a correction signal, phase shifting the correction signal to obtain a feedback signal and impressing the feedback signal onto the sample through means independent of the main probe coil.

Abstract: A variable external capacitor produces greater functionality for NMR probes by reducing the size of components and efficiently arranging the components. The variable external capacity has a cavity that allows adjustment tools to be extended through the variable external capacitor to adjust additional components that may be stacked above the variable external capacitor. The cavity may be used to house reactance such as a fixed capacitor or inductor connected in parallel with the variable external capacitor. The variable external capacitor includes a polytetrafluoroethylene housing configured to minimize its size and reduce lead lengths of the NMR circuit. A silver deposit plate on the polytetrafluoroethylene housing constitutes a stationary capacitor plate. A drum disposed inside the cavity and movably spaced from the stationary capacitor plate functions as a movable capacitor plate. An anti-rotation rail supports the drum to prevent rotation.

Abstract: A magnetically suppressed Faraday system for use in an ion beam treatment system, such as an ion implanter, includes a Faraday cage defining a chamber having an entrance, and a magnetic suppression assembly positioned at the entrance of the chamber. The downstream end of the Faraday cage is positioned adjacent to a workpiece such as a semiconductor wafer. The magnetic suppression assembly includes a suppression magnet structure for producing suppression magnetic fields of sufficient strength to inhibit escape of electrons from the chamber, a field cancellation magnet structure for producing cancellation magnetic fields for substantially canceling magnetic fields, produced by other magnets in the magnetic suppression assembly, near the downstream end of the chamber, and an angle correction magnet structure for producing angle correction magnetic fields selected such that the ion beam is subjected to zero or nearly zero net angular deflection as it passes through the Faraday system.

Abstract: Method and apparatus for reducing current leakage between overlapping conductive structures in a multi-layered integrated circuit device such as a thin film capacitor is described. A conductive structure operating as a raised lower electrode is preferably fashioned by step-like erosion using a photolithographic techniques atop a dielectric substrate. In accordance with this invention, the dielectric substrate itself is allowed to erode as well to space the conductive structure away from the problemmatic inner corners of the step. By so distancing such conductive structures, like electrodes, from these inside corners, even conventional deposition techniques can be used to fabricate a capacitive device of operational tolerance suitable for DRAM application without risk of unwanted electrode current leakage and possible shorting.

Abstract: A chromatography oven is described to achieve faster cool-down rates and to preferably lower the temperature difference that can be maintained between the oven temperature and ambient temperature. The oven includes a suitable housing having front and rear walls and four side walls, a fan within the housing adjacent to the rear walls, an ambient air intake vent means in the rear wall, and an exhaust vent means within a rear corner of one of the side walls adjacent to the rear wall for exhausting the tangential flow of air created by the rotating fan.

Abstract: An apparatus and method for precisely calibrating the transfer arm of a multiple station wafer processing system without breaking vacuum and with a minimum of system downtime is provided. A system of determining and properly aligning the crystallographic orientation of the wafers before processing as well as monitoring the orientation of individual wafers during wafer transfer between processing stations is also provided.

Abstract: A method of ion collection over a wide mass-to-charge range from continuous ion source into a quadrupole ion trap filled with a buffer gas directing an ion beam, from an external ion source to a radio frequency ion trap through a gating device for a predetermined period of accumulation time to allow the beam to enter the trap, trapping ions over a range of masses by applying a radio frequency voltage to the trap and changing an amplitude of the radio frequency voltage adiabatically to achieve a uniform trapping efficiency for ions over a predetermined mass range. The predetermined period of accumulation time may be divided into a plurality of segments, and the amplitude of the radio-frequency voltage is changing adiabatically within each segment.

Abstract: The use of audio signals from rotating samples in an NMR probe in a polarizing magnetic field as part of a nuclear magnetic resonance spectrometer for monitoring and remediating sample spinning speeds is presented.

Abstract: An improved echelle spectrometer comprises a slit in light blocking plate, an echelle grating, and a detector array. The slit is shaped and oriented to align an image of a light beam projected through the slit, onto the echelle grating and onto the detector in a desired orientation and shape relative to the detector array. Precise adjustment of the shape and orientation of the slit is dependent on the orientation of the detector with respect to the dispersion direction of the echelle grating. The echelle spectrometer provides high detector resolution with reduced read-out time.

Abstract: Electrode designs for reducing the problem of non-uniform etch in large diameter substrates are presented. The electrode opposite the substrate being etched in a plasma reactor can be tailored as to its shape so as to control the uniformity of the etching across the substrate. This is achieved with a number of generally dome-shaped electrode structures including generally cone-shaped electrodes, generally pyramidally-shaped electrodes and generally hemispherically-shaped electrodes. It is believed that non-uniformity of etching is due, at least in part, to excess ion density at the center of the reactor. The dome-shaped electrodes serve to disperse the high concentration of ions from the center of the reactor out toward the periphery of the substrate and thereby even out the ion density distribution across the substrate being etched. The electrodes are useable in diode plasma reactors, triode plasma reactors and ICP plasma reactors.

Abstract: An improved method of using an ion trap mass spectrometer is disclosed. According to the method an asymmetrical trapping field is applied to the trap. Preferably, the asymmetrical trapping field comprises a quadrupole field and a dipole field having the same frequency. In addition, higher order trapping field components, such as hexapole or octopole fields, may also be included, and the electrodes of the ion trap can be shaped to introduce such higher order field components. The effect of the asymmetrical trapping field of the present invention is to cause the center of the trapping field to be displaced from the mechanical center of the ion trap. A supplemental quadrupole field is then applied to the ion trap, the center of the supplemental quadrupole field being located at the mechanical center of the trap, i.e., it is displaced from the center of the trapping field. The supplement quadrupole field and the trapping field may be viewed as forming one combined field which acts upon the ions in the trap.