Abstract: An improved AC susceptometer and methodology for its use which is particularly suitable for the characterization of the properties of superconducting materials. Added to the circuitry of a conventional AC susceptometer is frequency domain analytical equipment for measuring the induced magnetic response. The addition of frequency domain measuring equipment permits the determination of the harmonic components of the induced magnetic response. The measurement of the harmonic components of the response also provides novel methodology for studying the phenomena of flux penetration, flux pinning and movement and permits the measurement of parameters such as lower critical field, critical temperatures, and the irreversibility line.

Abstract: A device for tapping the line power of a cable television distribution system. The device is intended for connection to a standard port of a cable tap. The device includes a threaded portion for connection to the port, a housing and an output connector mounted to the housing. Disposed within the housing is a module containing electronics forming a low pass filter to remove the line power from the RF television signal. The module is slidably mounted to extend out of the housing and is biased into engagement with the hot side of the port. The mounting of the electronics within a slidable module permits the low pass filter to be in close proximity to the port so as to eliminate interference with the television signal. The slidable housing also permits the device to be used with ports which differ in depth.

Abstract: A specimen holder for use in a charged particle beam device, notably an electron microscope, comprises a support and a resilient retaining element. The retaining element comprises a resilient ring which can be detached from the support or resilient tags which are attached to the support. A specimen is pressed against the support by the resilient retaining element. Such retaining of the specimen offers the advantage that the specimen can be readily disposed on the comparatively thin support and can be simply detached therefrom with a minimum risk of damaging.

Abstract: An improved AC susceptometer and methodology for its use which is particularly suitable for the characterization of the properties of superconducting materials. Added to the circuitry of a conventional AC susceptometer is frequency domain analytical equipment for measuring the induced magnetic response. The addition of frequency domain measuring equipment permits the determination of the harmonic components of the induced magnetic response. The measurement of the harmonic components of the response also provides novel methodology for studying the phenomena of flux penetration, flux pinning and movement and permits the measurement of parameters such as lower critical field, critical temperatures, and the irreversibility line.

Abstract: The measuring device (1) comprises a scale graduation element (3) provided with a number of tracks (9, 13), a pick-up device (5) which comprises a number of sensing elements (4, 6) provided with sensors, which number corresponds to the number of tracks (9, 13), and also comprises a signal processing system (7). The tracks (9, 13) include an incremental track (9) and an absolute track (13). Both tracks are formed as a succession of strip-shaped parts (11, 15), each of which has a property which can be detected by the sensors of the sensing elements (4, 6). This property is dependent on the location on the scale graduation element (3). This property is preferably bivalent. In the signal processing system (7) signals originating from the sensing element (4) associated with the incremental track (9) and signals originating from the sensing element (6) associated with the absolute track (13) are combined.

Abstract: An X-ray radiation detector is thermally conductively secured to the end of a cryogenically cooled copper cold finger in an evacuated atmosphere. A collimator having a conical radiation conduit at a relatively low evacuated pressure is thermally conductively secured to the end of the cold finger for passing radiation emitted by an electron microscope and reflected from a specimen to the detector in a windowless environment. The collimator and cold finger are at about the same cryogenic temperature. The detector is maintained at a temperature of a few degrees C. above that of the collimator. The collimator conduit radiation ingress aperture is dimensioned to limit gas flow to the conduit to limit moisture flow into the conduit and to the detector, the gas flow being molecular in a low pressure atmosphere.

Abstract: A low pressure gas discharge lamp (such as a fluorescent lamp) which includes a wire mesh grid disposed within the lamp envelope so as to intercept the electrons flowing between the lamp electrodes. A lead wire extends from the grid to the outside of the lamp envelope, when the grid is provided with a negative voltage with respect to the surrounding plasma the lamp may switched off. The grid controlled lamp eliminates the need for a solid state power switch in the lamp driving circuitry. As such, the lamp current flows only through the lamp not through the electronic ballast/lamp driving circuitry. With the lamp current removed from the ballast circuitry, power dissipation problems in the driver circuitry is eliminated. The grid controlled lamp design greatly facilitates circuit design.

Abstract: In an electron optical system a monopole shaped magnetic field is introduced enabling an aberration free imaging writing or detection in the system. Apparatus based on this field distribution result in improved secondary electron detection such as for chip inspection, in improved resolution in Auger electron detection for analysis, in a higher exactness in chip production in an electron beam pattern generator and in an electron beam image projector in which now also size reduction can aberration free be introduced.

Abstract: A material for use in a laser heterostructure which is lattice matched material to ZnSe and has a high band gap. The material is Mg.sub.y Zn.sub.l-y S.sub.x Se.sub.l-x with the ratio of sulphur to magnesium of 0.26/0.19. Lasing devices constructed from layers of this material and ZnSe can be either electron beam pumped or electrically driven.

Abstract: In a device for doubling the frequency of a light wave, a fundamental light wave 2 originating from a laser light source 1 is guided through a nonlinear optical medium 5 while forming a second harmonic wave 6. The nonlinear optical medium is formed from a polymer network and elements having a great hyperpolarizability. In the device, phase matching is realised by the application of a polymer network having a helical structure. The pitch of the helical structure is adapted to the phase-matching conditions by the selection of the polymerization conditions during the formation of the network.

Abstract: The present invention relates to a vacuum arc electron source having an anode and a cathode facing each other such that they produce a plasma (P) after an appropriate voltage difference has been applied between the anode and the cathode, an electron extractor device (30) and a material-retaining device arranged between the extractor device and the plasma source. According to the invention, the material-retaining device comprises, arranged in the electron extraction direction (F), at least one upstream baffle (10) and a downstream baffle (20) which are each electrically conducting and have apertures (16, 26) arranged in quincunx, such that when the baffles (10, 20) are adjusted a given potential, the plasma (P) does not extend to downstream of the downstream baffle (20).

Abstract: Suitable starting materials for the manufacture of a heavy metal fluoride glass composition are mixed with solid xenon fluoride as the fluoridizing reagent, after which the mixture is heated to temperatures between 200.degree. and 400.degree. C. in an inert atmosphere for a time which suffices to bring about fluoridation of the starting materials. The intermediate product thus obtained is melted thereby forming a stable glass composition of a high purity and a high transparency. The method can be carried out in a simple manner in a furnace which need not be gastight.

Abstract: Ultrafine particles (9) are produced from a target 30) by laser beam evaporation. The laser beam (1) is directed to the target in such a manner that the removal of the target material takes place in the direction of movement of the laser beam. The ultrafine particles thus manufactured are preferably used for the manufacture of single or multi-component materials or moulded bodies from such materials; by coating substrates (15) with said ultrafine particles.

Abstract: A device for detecting a centering error of a rotationally symmetrical surface (0.sub.1, 0.sub.2) of an object (0) with respect to a rotational axis (AR) about which axis the object is rotated for the purpose of the centering error detection is described. Two beams (b.sub.1, b.sub.2 ; b.sub.3, b.sub.4) at angles of approximately 90.degree. are directed onto the object and the variation in the phase difference caused by the centering error (.epsilon.) between the two beams (b.sub.1, b.sub.2 ; b.sub.3, b.sub.4) reflected by the surface is determined.

Abstract: The invention relates to a translation device comprising an actuator body and a coupling member which mechanically contacts said actuator body, the actuator body having at least one body of a solid electrolyte which is clamped between a pair of supporting surfaces and which is provided with at least one pair of electrodes between which mass transport takes place via the electrolyte under the influence of an electric potential difference, said mass transport causing the dimensions of the electrodes to change so that the coupling member is subject to a translation in a first coordination direction relative to a reference of the device. Preferably, AgI is used as the solid electrolyte and silver is used for the electrodes. On the basis of the above-mentioned principle, translation devices can be constructed for one, two or three-dimensional translations. Translations based on both translatory and rotatory motions are possible.

Abstract: In an infrared detector device for viewing an object or scene at more than one wavelength, the detector elements (10 and 20) are optimized to have appropriately different infrared responses by being formed in accordance with the invention in different levels (1 and 2) of different material on a substrate (3). Infrared concentrators (55) such as immersion lenses, light-pipes and/or reflectors collect incident radiation (50) over an area larger than the active portion of the associated detector element (10 and/or 20) and concentrate the radiation (50) onto the active portions. The arrangement adopted in accordance with the invention provides adequate space for at least one connection (15) of each upper-level detector element (10) to extend to the substrate (3) through an area of the lower level (2) which is located between the lower-level active portions on which the radiation (50) is concentrated by the associated concentrators (55).

Abstract: Magneto-optical waveguide having a magneto-optical layer (5) applied on a substrate layer (4). An accurate phase match is provided at a compact structure in that a thin layer is applied in uniform thickness on the overall surface area of the magneto-optical layer (5), which thin layer consists of an optically transparent non-metallic material and whose refractive index is less than the refractive indices of the magneto-optical layer (5) and of the substrate layer (4), and whose thickness is less than 0.3 .mu.m.

Abstract: In an optical heterodyne or homodyne receiver an optical system (140) is used in which the local oscillator beam (L) is combined with the signal beam (S). Simultaneously, these beams are split into orthogonally polarized sub-beams. For this purpose the optical system (140) comprises polarization-sensitive beam-splitting layers (141a and 141b) and neutral beam-splitting layers (142a and 142b) which function as beam-combining elements. In order to align the directions of the exit sub-beams of the signal beam (.sub.11, S.sub.12, S.sub.2, S.sub.22) and the local oscillator beam (L.sub.11, L.sub.12, L.sub.21, L.sub.22), the angles (.alpha., .beta., .gamma., .delta.) enclosed by the beam-splitting faces are chosen to be such that two angles located opposite each other have a combined magnitude of 180.degree.. This is realised by providing the layers (141a, 142b and 141b, 142a) on side faces of one prism (140a, 140b).

Abstract: Parallel heat paths are provided by three nested tubes, the outer tube being of stainless steel and connected cantilevered to a housing at ambient temperature. The innermost tube forms a cold finger having a negligible temperature gradient and secured in thermal conductive isolation concentrically within an intermediate cold sleeve tube which is also concentric within the outer tube, the cold finger and cold sleeve tubes being made of copper. The tubes have a minimum diameter and specular facing surfaces to minimize radiation coupling which is the major source of heat transfer between the tubes. The two inner tubes have minimum thermal conductive coupling via thermal insulating tapered rings at one end and a thermal insulating support at the other end. A radiation detector is secured to the inner cold finger tube for receiving X-ray radiation from a specimen in an electron microscope. The other ends of the two inner tubes ar thermally conductively connected to a heat sink Dewar via braided copper straps.

Abstract: In a spectrometer using a two dimensional CCD array as a detector a column or a substantial part of a column of pixels is used to detect radiation of a given wavelength. The output circuit (52) of the CCD is modified by taking the drain electrode of the pixel reset transistor (T1) to the reference voltage (VR) via a further transistor (T3) which is controlled by a column reset signal applied to input (63). A further capacitor (C2) is connected in parallel with the internal binning capacitor (C1) through transistor (T1). Since the further capacitor (C2) is "off chip" it can be made much larger than the binning capacitor (C1) thus allowing a whole column of pixels to be binned enabling a reduction in read-out noise.