Abstract: Substrate heating during sputter coating, due to charged particles, is controlled by the use of an auxiliary magnet in the vicinity of the substrate. The magnet is arranged to either increase this charge particle flux, in situations in which additional heating is desired, or reducing this charge particle flux in situations in which heating is detrimental (e.g., the sputter coating of heat sensitive substrates such as polymer films).

Abstract: Electrical equipment, such as telephone station apparatus, exposed to occasional, destructively high, voltage surges (e.g., lightning strikes) is protected by a device, placed in parallel with the equipment, including two electrodes defining a fixed narrow spark gap which breaks down (arcs over) to short the voltage surge to ground. The predominant failure mode of such devices is shorting across the narrow gap, due to electrode damage produced during the protective arcing mode. In the disclosed devices, the electrodes are contoured to define a narrow region, determining the protective breakdown voltage, and a wider region, sustaining the major part of the electrode damage. Shortly after the initiation of the protective discharge in the narrow gap region, the discharge moves into the wider gap region. Since the major portion of electrode damage is sustained by the wider gap region of the electrodes, the incidence of shorting failure is suppressed.

Abstract: The temperature variation of the bubble collapse field of a class of garnet magnetic bubble layer materials is selected by control of octahedral site substitution during layer growth. This permits the growth of layers, whose temperature dependence of critical magnetic properties more closely match the temperature dependence of bias magnet materials, resulting in extended operating temperature range and/or wider operating margins (with attendant improvement in manufacturing yield). Layer growth at higher temperature results in a larger rate of change of collapse field by producing greater octahedral occupation of predominantly tetrahedrally coordinated germanium.

Abstract: As a cryogenic refrigerant in an adiabatic demagnetization refrigerator, the intermetallic compound PrNi.sub.5 has been used to reach the millidegree Kelvin temperature range. The compound has a relatively large cooling entropy in this range and the specific heat peak, characteristic of materials of this class, occurs well below one millidegree. The material is easily solderable and is incorporated into a "cooling pill" by soldering to the metal wires or foils needed for producing thermal contact to the material to be refrigerated. The use of oriented crystals with their hexagonal axes perpendicular to the applied magnetic field is particularly advantageous. Suitable single phase PrNi.sub.5 bodies have been produced by annealing bulk melted samples, by Czochralski growth and by an extrusion method.

Abstract: Photolithography of microcircuits with elements in the micrometer size range is performed with X-ray exposure of photoresist layers through electron beam generated shadow masks. Synchrotron radiation from a particle accelerator is used as an intense source of well collimated X-rays and Bragg reflection from a mosaic crystal is used to provide spectral purity for good contrast in the exposed photoresist pattern.

Abstract: Electrical equipment, such as telephone station apparatus, exposed to occasional, destructively high, voltage surges (e.g., lightning strikes) is protected by a device, placed in parallel with the equipment, including two electrodes defining a fixed narrow spark gap. Such a device is designed to spark over with each surge and to recover afterward, restoring the line to its original condition. The predominant failure mode of such devices is shorting across the narrow gap, due to electrode damage produced during the protective arcing mode. In the disclosed devices, the electrodes define a narrow region, determining the protective breakdown voltage, and a wider region, sustaining the major part of the electrode damage. Shortly after the initiation of the protective discharge in the narrow gap region, the discharge is forced into the wider gap region by the provision, in at least one of the electrodes, of a high resistance path at the narrow gap region.

Abstract: High silica content optical glasses, containing more volatile oxides such as GeO.sub.2 and B.sub.2 O.sub.3, are produced by plasma fusion of powders without inordinately high loss of the more volatile constituents. The powders are produced by a process including the heat treatment of intimately mixed materials, which include the glass forming constituents. Small quantities of GeO.sub.2 are included in borosilicate glass to suppress bubble formation. Pairs of glass compositions have been found, with sufficient index of refraction difference to produce guidance in optical transmission lines, while possessing sufficient thermal expansion match to reduce stresses in the line.

Abstract: The temperature variation of the bubble collapse field of a class of garnet magnetic bubble layer materials is selected by control of octahedral site substitution during layer growth. This permits the growth of layers, whose temperature dependence of critical magnetic properties more closely matches the temperature dependence of available bias magnet materials, resulting in extended operating temperature range and/or wider operating margins (with attendant improvement in manufacturing yield). A preferred substitution species is lutetium, known as a dodecahedral site occupant, for which it has been determined that a significant and controllable octahedral occupancy can be produced by suitable choice of growth conditions.

Abstract: An electromagnetic signal processor intended, for use, primarily, in the hundred kilohertz to the several hundred megahertz range includes a filtering or wave shaping first stage. The filtering stage (or filter, if constructed as a separate unit) includes a length of lumped or continuous electromagnetic transmission line with all or a portion of the shunt capacitance, at each point along the line, being connected to a low input impedance summing device. The longitudinal distribution of capacitance, thus connected, determines the frequency response of the processor. Particularly simple realizations involving transmission lines with split ground planes and operational integrators are disclosed. Use in communications systems and nuclear instrumentation is discussed.

Abstract: The electrical conductivity of a lamella of conducting material (e.g., semiconductor wafers or metal films) is measured by introducing the lamella into the oscillatory magnetic field of the inductive element of the L-C tank circuit. The tank circuit is the frequency determining portion of an oscillator which is adjusted, upon sample introduction, to restore the magnitude of oscillation. With suitable choice of circuit parameters, the incremental current in the tank circuit is linearly proportional to the sheet conductivity of the lamella. An exemplary apparatus, operating at approximately 10 MHz with a 1 cm.sup.2 measurement area exhibited approximately 1% linearity over a 100 to 1 range of conductivity with a resolution of approximately one part in 10.sup.4 with a limiting sensitivity of 10.sup.11 carriers per square cm.

Abstract: Thin films of reactive metals in contact with layers of more noble metals, are etched by an etchant including a reactive cathodic inhibitor. The etchant is a hydrofluroric acid-based composition with hydrogen peroxide, a water soluble tetrazolium compound (the inhibitor) and a surface modifier, such as an alcohol or a more complex surfactant. For exemplary compositions, the undercutting of masking layers of noble metals or photolithographic materials is limited to the same order as the reactive metal film thickness.