Abstract: A method and apparatus which utilizes the hysteritic behavior of type II superconductors is provided for reducing the effective magnetic susceptibility of such high temperature superconducting materials being used close to the sample region in nuclear magnetic resonance system probes by providing decaying AC changes in the magnetic field parallel to said superconductive material. The method is particularly applicable to receiver coils. Reducing the effective magnetic susceptibility of superconducting receiver coils enables the improved sensitivity they inherently provide to be realized without loss of resolution resulting from line broadening caused by susceptibility discontinuities of materials near the sample region of the probe.

Abstract: A rotating sealing device for sealing between a wall separating two mediums under substantially different pressure and a rotatable shaft utilizes a combination of a liquid meatal seal comprising at least one liquid metal ring and a shield means which prevents contamination of the metal ring by gases coming into contact with the liquid metal. Magnetic fluid seal, a ring of an oil material, or inert gas may be used as a shield to protect the liquid metal.

Abstract: An X-ray tube has an anode and a photocathode inside a vacuum envelope and an electron multiplier is disposed between them. Such an electron multiplier may be a plurality of sequentially disposed dynodes or a microchannel plate. Because of the secondary electron emission from such an electron multiplier, a higher-power radiation is obtained without requiring a high optical power level to generate photoelectrons. The vacuum envelope may be of a rotary type with the anode and photocathode having annular regions.

Abstract: Radiation damping effects in NMR are compensated by splitting the amplified NMR signal induced in the main probe coil to obtain a correction signal, phase shifting the correction signal to obtain a feedback signal and impressing the feedback signal onto the sample through means independent of the main probe coil.

Abstract: A resonant coil for nuclear magnetic spectroscopy and microscopy is provided, in which the coil is in the form of nested, interrupted loops of a conductive material forming a distributed inductive element and having a plurality of capacitive elements with capacitance distributed over the periphery of the loops. The coil is preferably formed as a thin film of a superconductive material on an electrically nonconductive substrate.

Abstract: The present invention relates to improving the sensitivity of an NMR system for electrically conductive (polar) NMR samples. Many NMR samples use water or a salt solution of water or other electrically conductive liquid as a solvent for biologically active materials. When such a sample is placed in the probe coil of an NMR spectrometer, electrical losses in the conductive material lowers the Q of the receiving circuit and thereby reduces the sensitivity of the spectrometer. These electrical losses can be greatly reduced by breaking up the current paths within the sample. This can be achieved by a special sample cell that compartmentalizes the sample with electrical insulating material reducing the electrical current paths.

Abstract: An X-ray tube rotating anode is cooled with a liquid metal functioning as a recirculated heat exchange fluid and/or a metal film in a gap between the anode and a stationary structure. The liquid metal is confined to the gap by (a) a labyrinth having a coating that is not wetted by the liquid, (b) a magnetic structure, or (c) a wick. The liquid metal recirculated through the anode is cooled in a heat exchanger located either outside the tube or in the tube so it is surrounded by the anode. The heat exchanger in the tube includes a mass of metal in thermal contact with the recirculating liquid metal and including numerous passages for a cooling fluid, e.g. water. A high thermal conductivity path is provided between an anode region bombarded by electrons and a central region of the tube where heat is extracted.

Abstract: A seismographic sensor is constructed from a D'Arsonval movement. The elements of the movement include a coil suspended in the field of a permanent magnet and a pointer attached to the coil. A weight is attached to the pointer and acts as an inertia element. Leveling screws are provided to control the period of the weighted pointer and to control the resting position of the pointer. When the base of the meter vibrates during an earthquake, the weighted pointer does not follow the vibration because of its inertia, resulting in a relative rotation of the meter coil and the magnet field, thereby inducing a voltage in the coil. This voltage is proportional to one component of horizontal velocity of the earth's motion. Means are provided to process and record the magnitude of this voltage.

Abstract: A small sample of material is introduced into a vacuum to be analyzed, by ionization of atoms or molecular fragments of the sample using an electron or photon beam. The ionized species are trapped in a structure that defines electric fields or a combination of electric and magnetic fields in such a way that their motions are confined to the interior of the trap and that their motions within the trap are characterized by unique and discrete frequencies of oscillation dependent on the mass-to-charge ratio of the individual species. In order to provide for the detection of the frequencies of the motions, additional electrical signals are applied to the trapping structure so as to cause the motions to take place with a considerable degree of coherence. Alternatively, the coherence may be caused by creation of the ions during a very short pulse of the electron or photon beam at a position within the trapping structure but displaced from a positon of equilibrium.

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: The average power capacity of a rotating-anode X-ray generator tube is limited by the slow radiation cooling of the anode. The invention removes this limitation by rotating the entire vacuum envelope so the heat can be conducted directly to the air or to a circulating liquid. The cathode and anode are made as figures of revolution about the axis. A stationary source of X-rays is produced by focusing a stationary spot of the light onto a rotating photocathode. The photoelectrons are drawn off and focused onto a stationary spot on the rotating anode, to produce a stationary source of X-rays.

Abstract: A high-intensity X-ray source generates significant heat at the anode. To help dissipate this heat, the anode is often rotated in the vacuum. Heat must still be radiated from the anode to the exterior walls. An improved X-ray source incorporates the anode in the walls of the vacuum chamber and rotates the entire chamber. The heat is then easily conducted to the exterior where it may be dissipated by connection or forced air cooling.

Abstract: A microprocessor based electronic teaching aid which enables a student viewing a display containing text material being studied to designate any word or portion of text for definition or for vocalization by synthesized speech techniques wherein the reading material being studied is supplied in the form of a programmed Source ROM which contains pointers to the start addresses for the words of the reading material with reference to an internally provided dictionary. A program causes the creation of the text display responsive to the Source ROM data, and includes techniques for being able to define and vocalize any selected word. This combination of hardware and software permits a significant reduction in the cost of this teaching aid by elimination of disk drives or tape drives.

Abstract: A lens system for directing and focussing acoustic energy from an array of acoustic transducers on a small target can be made lightweight, low in absorption and dispersion by incorporating plastic Fresnel lenses with prisms into a monolithic tray of the same plastic with one lens for each transducer.

Abstract: Improvements are disclosed in an ultrasonic display and recording system of the type utilized in diagnostic medicine with particular applicability in cardiovascular diagnosis. The system includes a multi-element transducer for generating and receiving ultrasonic energy which is propagated into and reflected back from the cardiovascular region of the patient being examined, and also includes means for generating a two-dimensional real time display and/or image of the zone of examination. TM recording means are associated with the system and may be actuated to effect a TM recording corresponding to a preselected region of the real time image being observed. An ECG output signal is also displayed in real time with the two-dimensional image, and photographs of the displays may be produced at selected points in the ECG cycle in accordance with a setting made by the system operator.

Abstract: An electronic teaching aid which enables a student viewing a visual display containing text material being read or studied to designate any words or portion of said text for immediate audible vocalization or alternatively to designate any word of said test for immediate visual display of the definition of said designated word.

Abstract: An improvement in an ultrasonic imaging system is disclosed, enabling determination of volume and/or shape of three-dimensional portions of bodily tissue or the like.

Abstract: A real-time ultrasonic imaging system is disclosed which includes an array of transducers adapted for propagating ultrasonic energy into a body to be ultrasonically examined and for receiving reradiated energy from points within the body. A plurality of signal channels each includes a transmitter branch and a receiver branch associated with respective transmit and receive transducers, or both branches may share a single transducer. A transmitter branch activates a transducer to propagate the sonic energy and a receiver branch receives from the transducer electrical signals corresponding to the reradiated energy. Memory means in each receiver branch receive and store data indicative of the signal level passed to the channel by its associated transducer. Display means are provided for receiving the data from the memory means in each of the channels and for combining and processing such data to effect a real-time display of the bodily portion being examined.

Abstract: Improvements are disclosed in an ultrasonic display and recording system of the type utilized in diagnostic medicine with particular applicability in cardiovascular diagnosis. The system includes a multi-element transducer for generating and receiving ultrasonic energy which is propagated into and reflected back from the cardiovascular region of the patient being examined, and also includes means for generating a two-dimensional real time display and/or image of the zone of examination. TM recording means are associated with the system and may be actuated to effect a TM recording corresponding to a preselected region of the real time image being observed. An ECG output signal is also displayed in real time with the two-dimensional image, and photographs of the displays may be produced at selected points in the ECG cycle in accordance with a setting made by the system operator.

Abstract: A phased array ultrasonic imaging system is disclosed which combines aspects of both dynamic and pseudo-dynamic focusing. The system includes a linearly arranged array of side-by-side transducers adapted for propagating ultrasonic energy into a body to be ultrasonically examined and for receiving reradiated sonic energy from points within the body. A signal channel is connected to each of the transducers for activating same to propagate the sonic energy and for receiving electrical signals from the transducers (which correspond to the reradiated energy). Controllable delay means are provided in each of the channels for introducing linear phase shifts in the electrical signals proceeding in the channels during both transmission and reception to thereby azimuthally steer the transducer array. Means are further provided for processing the received signals proceeding through the channels and for combining same to effect a visual display of the bodily portion being examined.