Abstract: Synchronous apparatus capable of a variety of operational states responds to a sequence of digital control words, each specifying a desired state and persistence time of the state. The control words are furnished to the apparatus from a self-clocked FIFO in accord with the persistence code. A selected sub-sequence of digital control words in ROM is placed in an auxiliary FIFO upon detection of a corresponding token in the main sequence and control is passed to the auxiliary FIFO to furnish the sub-sequence to the apparatus. At the conclusion of the sub-sequence control is returned to the main FIFO and the main sequence is resumed.

Abstract: In order to increase the efficiency of solar cells, a monolithic stacked device is constructed comprising a plurality of solar sub-cells adjusted for different bands of radiation. The interconnection between these sub-cells has been a significant technical problem. The invention provides an interconnection which is an extremely thin layer of gold formed between the sub-cells by organometallic chemical vapor deposition. Such a layer tends to form beads which serve as a low resistance shorting interconnect while passing a large fraction of the radiation to the lower sub-cells.

Abstract: Several different embodiments of high-intensity rotating-anode X-ray are shown which use a liquid or fluid-cooled rotating-anode. No ferrofluid-type rotating joints or O-ring gasket-type seals are required so that the interior of the tube maintains a high vacuum without pumping. A bellows permits mechanical coupling to interior structures of the tube while providing a completely vacuum tight enclosure. All joints may be hard soldered or brazed together so the entire system can be baked at a high temperature during pumpdown.

Abstract: A wide bandwidth compressional wave transducer array obtains information concerning tissue of a subject being treated and supplies hyperthermia compressional wave treating energy to a treated region of the subject. The array transducers are pulsed on and off with an on duty cycle portion of less than one. An array of compressional wave imaging transducers is in the center of the array of compressional wave hyperthermia focused far field transducers used to analyze and treat. The power and duty cycle of the compressional wave hyperthermia focused far field are varied to control the energy incident on certain regions in a treated subject. The ultrasonic frequencies of hyperthermia beams derived from individual transducers are randomly angle modulated so the energy of adjacent far field focused beams overlaps to a greater extent than focused coherent beams.

Abstract: A free-electron laser has a wiggler for a linear electron beam comprising two sets of magnetic polepieces 26, 28 periodically spaced along opposite sides of the beam. The polepieces of one set 28 are displaced along the beam from the other set 26 by one-half period. A uniform longitudinal magnetomotive force generates fields between polepieces having transverse components 22 alternating between the sets 26, 28, providing a very short periodicity and hence, high frequency wave radiation.

Abstract: A gun for generating a multiple sheet beams 50 of electrons has a flat surfaced cathode 10 with parallel protruding ridges 12 of non-emitting material forming parallel focus electrodes for the sheet beamlets. A control grid of parallel bars 14 is aligned with the ridges 12 to reduce grid interruption. The beamlets may be focussed between support bars 54 of a foil anode 52 for passing the beam into a high-pressure volume such as a gas laser 48. The ridges are formed by inserting non-emissive bent sheets into grooves 58 in the cathode, which are dovetailed to hold them.

Abstract: Refractory metals or ceramics are diffusion bonded or densified by assembling the workpieces to be bonded, wrapping the assembly with carbon yarn, heating the wrapped assembly, cooling the assembly and unwrapping. The expansion of the workpieces together with the shrinking of the carbon yarn produces tremendous pressures which cause bonding and densifying of the workpiece.

Abstract: In a radiation therapy machine it is desirable to produce irregular radiation field shapes in order to shield critical organs not invaded by the tumor. A system is provided using a multileaf collimator formed of a multiplicity of heavy metal bar leaves driven relative to a pair of frames which are driven relative to jaws of a rectangular field collimator. A multiplicity of compensators, one attached to each leaf on one of the pair of frames is used to adjust the local intensity of the radiation within the field. The x-ray beam is limited to a fan with the jaws, the ends and selected parts of the fan are blocked by the multileaf collimator, and the intensity within various portions of the remaining beam is adjusted with compensators. The field of the fan beam is dynamically controlled by these means while the patient table is moved perpendicular to the plane of the fan beam.

Abstract: In a radiation therapy machine it is desirable to produce irregular radiation field shapes in order to shield critical organs not invaded by the tumor. A multileaf collimator is formed of a multiplicity of heavy metal bar leaves driven relative to frames which are driven relative to jaws of a rectangular field collimator by electric motors and flexible cables.

Abstract: A power supply for helix and collector electrodes of a traveling wave tube is driven by an AC power source having a frequency of at least 500 KHz. The helix supply includes plural, stacked voltage double AC to DC modules responsive to the 500 KHz source. The collector supply includes plural AC to DC modules, each having a diode full wave rectifier bridge, connected in stacked relation. Each of the modules includes a transformer with a ferrite, toroidal core dimensioned so that it is not driven into saturation by the 500 KHz source. Each module also includes inexpensive, signal switching diodes having a recovery time of approximately 4 nanoseconds. The ratio of the collector to helix DC voltages is maintained constant by threading a common lead through the apertures of the toroidal cores of the helix and collector modules. A separate common lead threaded through the apertures of the toroidal cores in the collector modules is connected directly to the 500 KHz power source.

Abstract: A slow-wave circuit for a TWT has periodic transverse plates extending across the axial by extending vacuum envelope. An opposed pair of apertures 24, 26 in each plate 20 couple adjacent cavities 28 between plates 20. Coupling apertures 24 in alternate plates 20 are rotated transverse to apertures 26 in the other plates to provide coupling only between adjacent cavities 28. Each plate 20 has transverse ridges 30 enclosing its axial beam aperture 22. The ridges 30 are orthogonal to the coupling apertures 24, 26 to increase beam coupling and decrease capacitance for wider bandwidth and higher impedance.

Abstract: An apparatus for planarizing an aluminum layer on a semiconductor wafer includes two deposition sources. The first source applies a refractory metal silicide layer to form a barrier to oxygen. The wafer is moved to a second deposition source which is an aluminum sputter device including a heater for the wafer, R.F. bias on the wafer and a magnetic mirror behind the wafer to move the plasma away from the wafer.

Abstract: An x-ray rotor structure wherein a target support stem has an externally threaded end portion brazed to an internally threaded surface of an encircling bushing which is provided with a barrier layer of oxidation restricting material. The stem is made of predominantly molybdenum material and the bushing is made of iron cobalt nickel alloy material having therein a small percentage by weight of titanium. The barrier layer comprises a layer of substantially pure nickel material which coats the entire inner surface of the bushing including the internally threaded portion thereof. Thus, the titanium is restricted from leaching to the surface during brazing and forming oxides which prevent the surface from being completely wetted by the brazing material. As a result, during brazing, the liquified brazing material alloys with the nickel material of the barrier layer to wet the inner surface of the bushing completely.

Abstract: A sputter coating module for a multifunction processing machine is provided in which the supporting mechanism for the workpiece can be isolated from the sputtering source, the pumps and other processing apparatus for cleaning without exposing the entire machine to atmosphere. The supporting mechanism which is rotatable from the horizontal to the vertical is hollow and mounted on hollow vacuum-sealed trunnions to allow passage of water, argon, and dry-nitrogen or air at atmospheric pressure into the interior of the supporting mechanism.

Abstract: Refractory metals or ceramics are diffusion bonded or densified by assembling the workpieces to be bonded, wrapping the assembly with carbon yarn, heating the wrapped assembly, cooling the assembly and unwrapping. The expansion of the workpieces together with the shrinking of the carbon yarn produces tremendous pressures which cause bonding and densifying of the workpiece.

Abstract: A scan controller for an ion implantation system includes a compensation circuit for generating a scanning signal from a triangle voltage signal. The scanning signal causes an ion beam to be deflected so that, in the variety of geometries describing the orientation of the target in the implantation system, the position of the intersection of the ion beam with the planar target surface changes linearly with time. In one embodiment the scanning signal has the form v(t)=-d -e/(t+c). In other embodiments the compensation circuit approximates the above function by means of polynomials.

Abstract: A method for pretreatment of a photoresist layer adhered to a semiconductor wafer prior to charged particle beam processing. The method includes bombarding the photoresist layer with ions which are electrically inactive with respect to the wafer. Suitable ions include ions of the noble gases. The pretreatment method causes rapid photoresist outgassing and carbonization without altering the electrical properties of the wafer. Outgassing during subsequent processing is thereby reduced. The pretreatment method is particularly applicable to ion implantation wherein dose measurement errors resulting from photoresist outgassing are reduced. The pretreatment method is performed at high current to minimize the effect on system throughput.

Abstract: A gyrotron interaction resonator 29 operating in a TE.sub.n1 cavity mode has an array of longitudinal slots 32 in the conductive wall 30. The slots 32 are spaced to couple to the unwanted TE.sub.n1 modes and to other modes of differing n and not to the desired mode. Wave-absorptive material 34 spaced from the inner cavity wall 28 and coupled to slots 32 absorbs the unwanted modes.

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: Wafer transfer apparatus for horizontal transfer of a wafer between a cassette and an input station of a vacuum processing system includes a wafer transfer arm with a primary section linked to a secondary section so as to move a wafer in a straight line to a location and orientation station and then to the input station. The actual location of the wafer center and the angular orientation of the wafer flat are determined, and the wafer is rotated to a desired angular orientation at the location and orientation station. A solar cell is used to sense actual wafer position by sensing the wafer edge as it is rotated. The required correction and rotation are calculated from the solar cell output. As the wafer is transferred to the input station, correcting displacements are added to the movement so that the wafer is accurately positioned at the input station. A strain gauge is used to reliably sense wafer presence or absence on the transfer arm.