Abstract: Disclosed is a detector for determining the location of wafers moving in a sputtering system, for example, to and from the sputtering chamber where the wafers are processed, including a capacitive transducer, located in the path of travel of the wafers, to which is coupled an oscillator supplying a constant current thereto. This current is detected by a sensor, whose output is processed and applied to a comparator. The comparator is preferably preset to supply a digital "0" when the current through the transducer is at a static or no-wafer condition, and a digital "1" when the capacity of the transducer changes due to the presence of a wafer in close proximity to the transducer which is sensed as an increase in current which is reflected as a change of voltage level applied to the comparator.

Abstract: Anisotropic etching of thick photoresist under plasma conditions to achieve a vertical side wall with or without undercutting is accomplished by operating at a low excitation frequency, a pressure in the range of 0.3 to 2 Torr and a controlled concentration of active species.

Abstract: An apparatus useful in the flameless atomic absorption spectroscopy analysis of a sample includes an electrically conductive sample carrier adapted to be heated whereby drying and ashing steps can be performed by passing an electric current therethrough. By use of such an apparatus, the temperature at which the ashing process occurs can be controlled.

Abstract: A chamber useful with an atomic absorption spectrometer includes at least two atomization means installed therein. The means can be serially aligned with the measuring beam or arranged parallel to the axis thereof.

Abstract: A plasma spray gun nozzle with fins for cooling. The fins are designed in the region radially outward of the point where the arc strikes the nozzle to have a base width and a slot width and slot depth having advantageous dimensions. Coolant is forced through the slots at a rate to achieve optimum heat transfer. Accordingly, the design for the nozzle used in its desired manner provide a plasma flame spray gun which will operate for an appreciably longer time than could prior art plasma flame spray guns before a gun failure is likely to occur.

Abstract: A method for concentrating a vapor of a mercury sample solution is carried out by an apparatus having an electrode of amalgam-forming material which electrode is movable from the sample solution to a heated portion within a tube.

Abstract: A modified cordierite (2MgO.2Al.sub.2 O.sub.3.5SiO.sub.2) composition in which at least a portion of the silicon dioxide is replaced with germanium oxide. These compositions have low thermal expansion, excellent formability and thermal shock resistance making them especially suitable for the manufacture of mirror substrates to be used at elevated temperatures. By selecting the proportion of germanium oxide according to the intended operating temperature, substantially zero thermal expansion can be achieved between room temperature and the selected operating temperature. Methods of manufacturing the material and of selecting the thermal expansion characteristics are also disclosed.

Abstract: An apparatus and method useful for analyzing refractory substances includes a means for locally heating a sample portion of a refractory material to generate the dissociated vapor thereof.

Abstract: In particle beam optical instrumentation, an array of conventional sputter ion pump cells distributed in a ring shaped array about the circumference of the volume (optical column) to be pumped. An axially symmetrical, hollow, toroid magnetic circuit, formed by axially symmetrical magnets, either of the permanent type or of the electromagnetic type (or a combination of both), is used and the pumping action is outward from the central throughbore in the column so that the bore space could be occupied by other instrumentation. The magnetic circit may be used for particle beam focusing (optical lens) as well as for the pumping action by introducing magnetic gaps in either a series or parallel configuration.

Abstract: An optical coupling device for providing an oxygen-free optical path between a plasma torch and a monochromator includes a hollow body having means associated therewith for the venting thereof.

Abstract: A sampling valve useful in liquid chromatography includes a stationary valve member and a valve member movable with respect thereto. The movable valve member includes an axial bore having a cross-section permitting the insertion therethrough of a sample injection needle.

Abstract: A discrete-time analog filter for eliminating a variable frequency carrier of an amplitude-modulated signal. The filter comprises a plurality of unit delay circuits, each of which is sampled at a rate which varies in proportion to the frequency of the carrier so as to automatically tune the filter's reject band to follow the carrier frequency.

Abstract: A dissociation chamber and measuring cell combination which is useful for making atomic fluorescence measurements includes a heated dissociation chamber and a measuring cell separate therefrom. The combination is particularly useful for use with elements which form hydrides of the sought element.

Abstract: A precise lamp positioner for moving a lamp relative to a lens. The lamp is carried at one end of an L-shaped pivot plate which is pivoted at its corner to the free end of a pivot arm. The pivot arm is pivoted at its other end to a base. The pivot plate is pivoted about its pivotal connection at its corner by a plate position adjustment means. The pivot arm is pivoted about its pivotal connection to the base by an arm position adjustment means. By adjusting both adjustment means, the lamp position relative to the lens can be precisely set. The pivot plate also pivots about the pivotal connection at its corner so it can swing relative to the base to allow replacing the lamp if it fails.

Abstract: An apparatus for reducing the leakage current error from a resistance furnace includes a grounded electrically conductive member, an electrically insulating, thermally conductive member adjacent thereto, which thermally conductive member is contacted by a thermocouple junction.

Abstract: The disclosed circuitry for integrating an analog voltage signal with respect to time, t, while simultaneously dividing the integral by time, t, is valuable for use in medical pulmonary analyzers and includes a ramp generator for developing a voltage level proportional to time, a duty cycle modulator for generating an inverted time signal, 1/t, a multiplier for multiplying the analog voltage signal, V, by the inverted time signal, 1/t, followed by an integrator to produce the required output of 1/t .intg.V dt.

Abstract: A phase synchronization apparatus useful for synchronizing the sample signal and the demodulation signal at a spectrometer includes a stepper motor the position of which is controlled so that the desired phase synchronization is ensured.

Abstract: An apparatus for automatically compensating for deviation of a capacitance manometer reading from true pressure. The capacitance manometer is connected to a source of pressure having a value less than the pressure the capacitance manometer is capable of reading and the indicated pressure is stored as a correction factor. Thereafter, each pressure read by the manometer is adjusted by the correction factor.

Abstract: A system for machining a glass workpiece comprises means for rotating the workpiece. A concentrated beam of energy is axially directed to the surface of the workpiece to soften the glass material. The softened glass material is then removed by a pointed or relatively narrow tool which is precisely located with respect to the area treated by the energy beam.

Abstract: An improved photodetector arrangement comprises positioning a photodetector having at least one semitransparent cathode so that the light beam striking the cathode passes through it at least twice before exiting from the photodetector. In another embodiment of the invention, a second photodetector is positioned relative to a first photodetector so that the light beam, after striking the first photodetector, strikes the second photodetector. Where the two photodetectors are employed, they may be electrically connected in parallel.