Abstract: A unique configuration control mechanism is disclosed which provides a fault-free verification of digital hardware and software modules, as well as verification of the logic control circuits used to drive said modules.

Abstract: A heater for an indirectly heated vacuum tube cathode is formed of anisotropic pyrolytic graphite in which current passes through the graphite in the "c" direction.

Abstract: An electrostatic chuck for releasably holding a workpiece comprising a substrate formed by a pair of dielectric elements, each being a single crystal, with at least one electrode embedded therebetween, and a voltage source coupled to each electrode. The chuck is preferably fabricated from two substantially planar dielectric members sandwiched around a brazing compound which become electrodes after the assembly is heated and then cooled.

Abstract: An X-ray tube construction of the rotating anode type for reducing acoustic noise and vibration by using granules which are placed loosely within an anode cavity formed between the outer surface of an anode shank and a wall of an anode sleeve in proximity to a bearing journaled to a rotor shaft for rotation of an anode structure.

Abstract: An impregnated cathode comprising three layers: a very thin emitting surface layer of metal such as an alloy of tungsten with a high fraction of an activating metal of the platinum group to provide low workfunction; an underlying, thin buffer layer of porous tungsten alloyed with a fraction of activating metal, to retard diffusion loss of activating metal from the emitting layer; and a substrate of porous tungsten impregnated with barium aluminate.

Abstract: A magnetron sputter apparatus is disclosed which includes a rotatable generally heart-shaped, closed-loop magnet array behind the target and in front of a pair of separately driven stationary electromagnets. The apparatus is optimized to produce a sputtered film on a planar substrate having desired film characteristics such as uniformity of thickness, good step coverage, and good via filling and efficient utilization of the target. The shape of the generally heart-shaped array includes a flattened tip forming an arc of a circle centered on the axis of rotation and concave cusps in the lobes of the heart-shape. The electromagnets are used to increase target utilization at its center and to compensate for the change in shape of the target and distance from the target to the substrate with depletion.

Abstract: A method for using a QIT and for performing collisionally induced disassociation MS.sup.n experiments by scanning the trap potential sequentially so that the field first experiences a secular frequency of a selected parent ion and then the secular frequency of a CID produced daughter ion and then the secular frequency of a granddaughter ion and so on for each secular frequency of each progeny ion in descending mass order.

Abstract: A hysteretic high-T.sub.c trilayer Josephson junction, and a method of forming the same are disclosed. The junction includes lower and upper high T.sub.c superconducting cuprate films separated by a barrier layer, where the thin films each include a molecular junction layer adjacent the barrier layer which is characterized by a high-T.sub.c cuprate stoichiometry and crystal structure, and a flat two-dimensional surface, as evidenced by its electron diffraction pattern using reflected high-energy electron diffraction. The junction and barrier layers in the junction are formed by atomic layer-by-layer deposition.

Abstract: A method of using a quadrupole ion trap mass spectrometer for high resolution mass spectroscopy is disclosed. High resolution of a mass spectrum of a desired species is achieved by first using a slow scanning rate and by first ridding the trap of unwanted ions. Accurate mass calibration is achieved by using a reference compound of known mass and using a second supplemental AC dipole voltage to eject the reference ions at nearly the same time as the sample ions of interest are ejected from the trap. This eliminates the need to scan the trap between the masses of the sample and reference ions. Space charge in the trap is held constant, thereby eliminating a major source of mass axis instability, by using the results of one scan to control the ionization time during the next scan. Preferably, during ionization a broadband supplemental dipole voltage is applied to the ion trap to rid it of unwanted ions.

Abstract: A method for efficiently filling a QIT which isolates an ion range by employing a sequential part of supplemental broadband waveforms where the first such supplemental broadband waveform is applied during the period that the e-beam ionization bombardment takes place and the second such broadband waveform is applied after the e-beam bombardment ends.

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: A standing wave type of microwave linear particle accelerator (40) has a sequence of microwave cavities (42), (43), (44), operated in the standing wave mode, with drift tube conduits (31), (32), (33), between them to permit the passage of a beam of charged particles which are accelerated by the electric fields in each cavity. The first cavity (42) into which the particles enter has a conduit (30) comprising a drift region connected to the particle entrance port (2), outlined by a re-entrant nose (3) extending into the first cavity (42). The drift tube conduit (31) between the first and second cavities (42, 43) has a tapered interior, and the diameter at the upstream end is less than the diameter of the conduit (30) in the re-entrant nose (3) of the first cavity (42). This structure significantly reduces the back bombardment of particles moving backward through the port (2), and increases the efficiency of particle focusing and bunching in the first cavity (42 ).

Abstract: Improved methods of using an ion trap mass spectrometer, whereby AC voltages supplemental to the AC trapping voltage are used for scanning the trap, for conducting chemical ionization experiments, and for conducting MS.sup.n experiments, are shown. In one embodiment a broadband supplemental AC voltage is applied to rid the trap of ions above or below a preselected cutoff mass. This is particularly useful in conducting chemical ionization experiments for eliminating high mass sample ions that are formed when the reagent gas is ionized by electron impact ionization. Likewise, this technique may be used to eliminate low mass reagent ions when conducting an electron impact ionization experiment in the presence of a reagent gas. In another embodiment a non-resonant, low-frequency supplemental voltage is applied to the trap causing trapped ions to undergo collision induced dissociation. Multiple generations of ion fragments may be simultaneously formed in this manner, thereby enabling MS.sup.n experiments.

Abstract: A variable cooling time is imposed on ions in a quadrupole ion trap prior to excitation through border effect operation. Continuous variation of the cooling time brings about continuous variation of the selected ion internal energy when subjected to the boundary effect such that the boundary effect competes more favorably with ion loss in the trap, and fragmentation reaction channels having successively greater energies of activation can be accessed preferentially.

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: Method employing low pressure plasma having high electron density for rapid oxide etching employing hydrogen and argon and specific electron clyclotron resonance (ECR) operating parameters in an ECR having a non-oxygen contributing environment in the reaction chamber.

Abstract: Turbomolecular vacuum pumps having structures which provide increased pumping speed, increased discharge pressure and decreased operating power in comparison with prior art turbomolecular vacuum pumps. In a first embodiment, the stators of one or more axial flow vacuum pumping stages in proximity to the exhaust port of the vacuum pump have progressively lower conductance so that the bulk velocity of the gas being pumped is increased. In a second embodiment, one or more stages near the inlet port of the vacuum pump are provided with a peripheral channel to utilize the centrifugal component of the gas being pumped. In a third embodiment, one or more stages in the vacuum pump are molecular drag stages, each including a disk rotor. One or more pumping channels in the stator adjacent to the upper surface of the disk are connected in series with one or more pumping channels adjacent to the lower surface of the disk.

Abstract: A new method for accurately and sequentially growing monolayers and creating new superlattice structures employing a MBE thermal source control technique employing a quasi-double beam atomic absorption background correction measurements with the beam blocked and with the beam unblocked and by calculating the concentration based on the: ##EQU1## and applying corrections for non-linear absorption curves because of comparable spectral bandwidth of the molecular beam.

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: Turbomolecular vacuum pumps having structures which provide increased pumping speed, increased discharge pressure and decreased operating power in comparison with prior art turbomolecular vacuum pumps. In a first embodiment, the stators of one or more axial flow vacuum pumping stages in proximity to the exhaust port of the vacuum pump have progressively lower conductance so that the bulk velocity of the gas being pumped is increased. In a second embodiment, one or more stages near the inlet port of the vacuum pump are provided with a peripheral channel to utilize the centrifugal component of the gas being pumped. In a third embodiment, one or more stages in the vacuum pump are molecular drag stages, each including a disk rotor. One or more pumping channels in the stator adjacent to the upper surface of the disk are connected in series with one or more pumping channels adjacent to the lower surface of the disk.