Abstract: A broadband optical detector is disposed to measure the total intensity I(.lambda., .alpha.) attributed to a portion of the optical spectrum passed by a sharp bandgap optical transmission element as the bandgap is caused to translate over a desired wavelength interval by a band gap control parameter, T. The differential spectrum of the incident optical radiation is recovered by the differentiation of I(.lambda., .alpha.) in respect to the parameter T.

Abstract: Apparatus for electrostatic clamping of a semiconductor wafer in a vacuum processing chamber wherein an ion beam is applied to the wafer. In a first embodiment, the apparatus includes an electrically conductive platen, a resilient, thermally-conductive dielectric layer affixed to the platen and one or more conductive wires positioned on the clamping surface. A clamping voltage is applied between the wires and the platen to firmly clamp the wafer against the clamping surface and depress the wires into the resilient dielectric layer. In a second embodiment, a three-phase wafer clamping apparatus includes a platen divided into three electrically isolated sections. One phase of a three-phase clamping voltage is connected to each of the platen sections. In the three-phase configuration, the wafer charging current is very small, and the clamping force is essentially constant. In a third embodiment, a six phase wafer clamping apparatus includes a platen having six symmetrically located electrodes.

Abstract: An apparatus and method for control of a shape of a solidification interface in a Czochralski crystal pulling process are provided wherein a bottom heater is disposed below the bottom of the crucible, the bottom heater having a plurality of individually controllable heating elements which are selectively controlled to produce a desired radial temperature distribution across the bottom of the crucible, thereby influencing the flow pattern within the melt.

Abstract: Apparatus for detecting abnormal vibration in a shaft, such as a rotating crucible holder drive shaft of a crystal puller, has a pair of sensors disposed 90 degrees with respect to each other. The signals are high pass filtered and added together, then low pass filtered and full wave rectified to operate an alarm and strip recorder. A method for detecting vibration in a shaft comprises sensing vibrations in the shaft, filtering the sensed signals, and rectifying the filtered signals.

Abstract: Apparatus for detecting abnormal vibration in a shaft, such as a rotating crucible holder drive shaft of a crystal puller, has a pair of sensors disposed 90 degrees with respect to each other. The signals are high pass filtered and added together, then low pass filtered and full wave rectified to operate an alarm and strip recorder. A method for detecting vibration in a shaft comprises sensing vibrations in the shaft, filtering the sensed signals, and rectifying the filtered signals.

Abstract: An apparatus and method employing an interface heater segment for control of a shape of a peripheral edge region of a solidification interface in a Czochralski crystal pulling process are provided wherein an interface heater segment, independently controllable from a primary heater, is provided at the level of the solidification interface around the periphery of the crucible, the interface heater segment being selectively controlled to influence the shape of the solidification interface at the peripheral edge region thereof, in order to eliminate problems experienced with edge downturn at the peripheral edge region of the interface.

Abstract: An apparatus and method employing a radiative heater for control of a shape of a peripheral edge region of a solidification interface in a Czochralski crystal pulling process are provided wherein a radiative heater element, independently controllable from a primary heater, is provided above the upper level of the melt and of the solidification interface around the periphery of the crystal, the radiative heater element being selectively controlled to influence the shape of the solidification interface at the peripheral edge region thereof, in order to eliminate problems experienced with edge downturn at the peripheral edge region of the interface.

Abstract: A method for dynamic focus of received energy, in a vibratory energy imaging system, into a beam in which contribution from transducers in an array of N such transducers, are progressively enabled to contribute to beam focussing dependent upon distance between a particular j-th transducer (where 1.ltoreq.j.ltoreq.N) is responsive to the depth, or range R, of the focal point at any instant of time; the initial steering angle .theta., with respect to the array normal, is used in conjunction with a range clock, to determine the time when each off-normal transducer channel is enabled to add to the beam (dynamic apodization) and to finely adjust the channel time delay to properly focus the beam after the enablement of the channel.

Abstract: A computerized process to generate ply patterns for manufacturing industrial parts by stacking and molding a large number of plies is based on solid modeling. The outermost shell of the part is unfolded to a planar pattern using a surface development procedure. The part is decomposed based on the ply thickness; the shell with the ply thickness is removed from the solid model once the surface is unfolded. A set of ply patterns are formed by repeating the unfolding process until no more volume remains. More accurate patterns are produced in less time, especially plies for complexly shaped composite parts such as aircraft engine components.

Abstract: Rapid x-ray inspection of objects larger than an x-ray detector array is based on a translate rotate scanning motion of the object relative to the fan beam source and detector. The scan for computerized tomography imaging is accomplished by rotating the object through 360 degrees at two or more positions relative to the source and detector array; in moving to another position the object is rotated and the object or source and detector are translated. A partial set of x-ray data is acquired at every position which are combined to obtain a full data set for complete image reconstruction. X-ray data for digital radiography imaging is acquired by scanning the object vertically at a first position at one view angle, rotating and translating the object relative to the source and detector to a second position, scanning vertically, and so on to cover the object field of view, and combining the partial data sets.

Abstract: Detection of the breakthrough of a laser beam through a workpiece wall uses one or more magnetic field pick-up coils. The coils are disposed on the drill side (side upon which the laser beam is impinging) of the workpiece. The coils sense the magnetic fields generated in the ionized plasma of particles escaping from the impact of the laser on the surface. The coils are connected to a breakthrough detector which generates a breakthrough signal upon the plasma and associated magnetic fields disappearing at breakthrough. The breakthrough signal is used to turn off the laser and/or change the application point at which the laser beam strikes the workpiece.

Abstract: A phase-difference eddy current imaging system has a bridge circuit including a pair of coils with one or both coils disposed proximate an object that may contain one or more flaws. An oscillator is coupled to the bridge circuit and also to a pair of phase detectors that are coupled to the coils. A differential amplifier is coupled to the phase detectors for providing a comparison signal. A method for eddy current imaging using phase difference detection comprises providing relative movement between an object and at least one of a pair of coils, measuring the phase of the effective reactance in each of the coils, comparing the measured values, and formatting the compared values as a function of spatial position.