Abstract: A digital radiography system includes an X-ray source for projecting a beam of X-rays toward and through an object to be examined onto the input face of an image intensifier tube. A multi-hole collimator is disposed between the object and the image intensifier tube for producing a two-dimensional array of spaced pencil beams, and these pencil beams are raster scanned relative to the object being examined and across the input face of the image intensifier tube through small distances corresponding generally to the distance between the holes in the collimator. The succession of images which are produced on the output face of the image intensifier tube during the scanning of the pencil beams are scanned by a video camera whose output signals are digitized and stored as partial images, and the partial images are thereafter interleaved with one another to provide a composite comparatively high resolution image of the object being examined.

Abstract: Penetrating radiant energy imaging system employs a scanning pencil beam of radiant energy. In some embodiments of the invention, the cross-section of the beam varies in a controlled manner; in a disclosed embodiment the beam has either one or another cross-section. A detector responds to incident radiant energy passing through a target and provides signals to a processor which produces from the signals a pair of image arrays, each array consisting of signals generated by the scanning pencil beam of one cross-section or the other. Increased contrast and/or resolution is provided by selectively combining the signals in the image arrays. In other embodiments of the invention, specifically related to tomographic imaging, rather than controlling the cross-section of the radiant energy at the source, the cross-section of the radiant energy is controlled at the detector field.

Abstract: The detector signal in an X-ray scanning system is electronically analyzed; when the system resolves an object too small to be visualized when displayed in a standard shadowgraphic format on a cathode ray tube, a generated marker appears on the cathode ray tube display representative of the object's location and size/density.

Abstract: A flying spot X-ray scanning system includes a grid controlled X-ray tube and associated collimators for producing a pencil beam of X-rays which is adapted to repeatedly scan along a line through a body to be examined and across an associated detector. The grid of the X-ray tube is energized by a train of rectangularly shaped pulses, and separate control means are provided for selectively varying the commencement of each such pulse thereby to determine the position of the scan field relative to the body being examined, and for selectively varying the duration of each pulse thereby to control the width of the scan field. The X-ray tube, collimators, and detector are adapted to be moved as a unit in a direction transverse to the scan line of the pencil beam, and a further control is provided for selectively varying the extent of this transverse movement thereby to control the longitudinal dimension of the scan field.

Abstract: A high resolution detector having a scintillation crystal for receiving incident X-rays at a front face and interacting with the radiation to generate corresponding visible light radiation. Silicon photodiode arrays are positioned on top and bottom lateral faces of the scintillation crystal to receive the visible light that is radiated laterally with respect to the direction of propagation of the incident X-rays. Photodiode elements in each photodiode array extend from the forward face of the scintillation crystal in the direction of propagation of the incident X-rays. The length of the photodiode elements determines the radiation stopping power of the high resolution detector and the height of the front face of the scintillation crystal determines the resolution of the detector. The height of the forward face of the crystal may be made small with respect to the length of the photodiode elements to provide a detector having high resolution and high radiation stopping power.

Abstract: A concentrating solar collector includes a radiation reflective surface having the configuration of a paraboloid of translation, the axial extent of the paraboloid being the portion between the apex and the plane perpendicular to the axis and passing through the focus. A receiver of reflected radiant energy is located along the focal line of the paraboloid, and includes a receiver entrance aperture whose plane is oriented at an angle to the axis, preferably at an angle of 29.degree..+-.10.degree.. The width of the entrance aperture is a function of the distance between the lip and axis of the parabola and the angular radius of the sun.

Abstract: A meter pulse initiator is employed to generate signals corresponding to the rotation of the rotor of a watthour meter. Infrared light emitting diodes (IREDs) receive a small steady state driving current and radiate two low intensity beams of radiation that are reflected from the surface of a rotating rotor. A creep hole in the rotor passes beneath one of the beams and transmits the low intensity radiation to an associated phototransistor. A small current is induced in the phototransistor and the current is amplified by a Darlington amplifier. The amplified current is applied to the IRED to increase the intensity of the radiation of the IRED in a positive feedback loop. Component saturation defines a peak driving current and an associated peak radiation intensity for the IRED. As the phototransistor current increases, a capacitor is charged to a threshold voltage and after the creep hole passes the IRED/phototransistor pair, the capacitor discharges.

Abstract: A scanning X-ray imaging system produces an image of the transmissivity of objects by producing a relative motion of the object generally perpendicular to the triangular planes joining an X-ray point source and M X-rays pass through a scanning slit assembly. The scanning slit assembly generally includes a plane of X-ray opaque material having N sets of line slits, where N is equal to or greater than 2, each set containing MMidentical line slits. The scanning slit assembly, in addition, includes a rotating X-ray opaque material containing N uniquely different sets of slits, each set containing identical slits. Each of the N sets of slits is uniquely paired with each of the M . N line slits. During any scan of an object, M detectors, M line slits and one of the N sets of slits are used. The scanning X-ray imaging system provides N selections in image resolution of the scanned object. The selectivity provides radiographic images with different contrast resolution and/or spatial resolution.

Abstract: An apparatus for simultaneously obtaining both non-dispersive and spatially-resolved soft x-ray spectra from a distributed soft x-ray source. A charge coupled device (CCD) camera having a back-illuminated CCD is irradiated by an x-ray source and a mechanical shutter or electronic shutter effect is used to define an integration period for the pixels of the CCD that ensures that the probability of a single pixel receiving more than one photon during the integration period is small. The magnitude of the charge at each pixel over an integration period is stored in a memory device and, after a plurality of integration periods have passed, the stored data for each pixel may be individually analyzed or combined and displayed to image the x-ray source.

Abstract: An X-ray lithography system for the production of micro-electronic circuits, of the type comprising a mask having detailed circuit patterns thereon which are irradiated by soft X-rays onto a wafer covered with a photosensitive material to replicate the mask patterns, includes an X-ray source spaced from the mask and operative to produce a plurality of input beams of X-rays which are substantially collimated by an array of grazing incidence mirrors to produce a plurality of output X-ray beams which are spaced from one another at the output of the collimator and which are projected in substantially parallel relation to one another toward the mask. Each output beam exhibits a small divergence which causes the several output beams to merge into a single, comparatively large cross-sectional area, composite beam of X-rays at a plane spaced from the collimator. The mask is positioned substantially in said plane for illumination by the composite beam of X-rays.

Abstract: A scanning X-ray imaging system produces an image of the transmissivity of objects by producing a relative motion of the object generally perpendicular to the triangular planes joining an X-ray point source and M X-ray line detectors, where M is equal to or greater than 1; these X-rays pass through a scanning slit assembly. The scanning slit assembly generally includes a plane of X-ray opaque material having N sets of line slits, where N is equal to or greater than 2, each set containing M identical line slits. The scanning slit assembly, in addition, includes a rotating X-ray opaque material containing N uniquely different sets of radial slits, each set containing identical radial slits. Each of the N sets of radial slits is uniquely paired with each of the N sets of line slits. During any scan of an object, M detectors, M line slits and one of the N sets of radial slits are used. The scanning X-ray imaging system provides N selections in image resolution of the scanned object.

Abstract: An arc-shaped X-ray beam penetrates an arcual cross-sectional area of a body and the attentuated transmitted beam irradiates a portion of a circular array of detectors on a rotating disc. The detectors operate to generate signals proportional to the intensity of the incident transmitted radiation. The beam and detectors are moved along the axis of the body during rotation of the disc to irradiate adjacent cross-sectional areas of the body. A computer operated CRT receives the detector signals and displays an image of the radiation attentuation characteristics of the scanned arcual areas.

Abstract: A CT scanner having a rotating X-ray source and a stationary circular array of 600 contiguous detectors includes a sliding shutter mechanism incorporated in the precollimator system that prevents detectors at the beginning and at the end of a scan from receiving radiation while progressively increasing and decreasing, respectively, the current to the X-ray tube.

Abstract: A remote load controlling apparatus receives a disconnect signal on a line that is filtered and voltage limited. This disconnect signal sets a flip-flop which enables an oscillator and a solid-state switch. The enabled switch energizes a relay to disconnect the load from electric service. A counter counts the output of the enabled oscillator and provides a flip-flop reset signal after a local time delay that is determined by a particular incremented count state of the counter. The reset flip-flop disables the oscillator and solid-state switch to de-energize the relay and reconnect the load to electric service. The flip-flop may also be reset by a remote signal to disable the oscillator and solid-state switch and reconnect the load before the counter is incremented to its particular incremented count state. A second counter and a second solid-state switch may be added to ensure that the load is connected to electric service if a component of the apparatus should fail.

Abstract: An X-ray detecting system includes a number of X-ray detectors mounted on the periphery of a vertical ring rotatable about a patient to be scanned diametrically opposite from an X-ray tube, slit collimator and chopper wheel mounted on the ring. Each detector includes a scintillator crystal typically of NaI, a photomultiplier tube that receives light from the crystal proportional to the incident X-rays, an amplifier energized by the output of the photomultiplier tube that provides a proportional signal to an LED that energizes both the photomultiplier tube (PMT) to provide light feedback and a photodiode that provides an electrical output signal so that the total current at the PMT anode resulting from X-ray light and LED light is constant. Circuitry is preferably included so that the LED supplies only the chopped part of the X-ray equivalent light signal with practically no d-c component.

Abstract: Inert gas under pressure forces a suspension of particles in a carrier fluid through a flow channel including tubes of narrow diameter at a pressure high enough to establish laminar flow free from turbulence at a speed determined by a constant displacement rate syringe at the downstream end of the flow channel. At at least two locations along the flow channel measurements are made of particle conditions, such as radioactivity and size, to provide a multiple of particle signals which are correlated to provide a multi-dimensional characterization of the particles, such as the number of cells exceeding a predetermined radioactivity level for each of a number of cell size ranges.

Abstract: The detection of malignant or dysplastic cells in a tissue sample, by treating the sample with a solution containing radioactive gallium and relying upon the greater take-up of the gallium by the malignant or dysplastic cells relative to normal cells to provide a detectable signal of malignancy, is improved by including non-radioactive preemptive species in the solution to pre-empt potential gallium binding sites in protein molecules of normal cells. The pre-emptive species may be one or more of scandium, indium or yttrium.

Abstract: An X-ray inspection system includes a circuit that responds to a high level of opacity for more than a predetermined time interval by providing an alarm signal to alert the inspector of the possibility of concealed contraband. The circuitry also provides a pulse when exceptional opacity is detected for combination with the vertical deflection signal to translate the display of exceptionally opaque objects to a different portion of the viewing screen to facilitate identification of potential contraband without opening the baggage or parcel being inspected.

Abstract: A tilted drum having an X-ray opaque rim formed with slits parallel to the drum axis has a rim portion interposed between an X-ray tube and an X-ray opaque stationary surface formed with a slit perpendicular to the drum axis to provide a scanning pencil beam of X-rays of rectangular cross section as the drum rotates about its axis.

Abstract: A remote meter-reading system interrogates meter stations over power lines and receives encoded meter readings over the power lines in synchronism with the power line frequency by superimposing a digitally modulated signal over the 60-Hz power frequency. The central control station transmits at a data rate of 60-baud and receives at a data rate that is 60-baud or a submultiple thereof, to reduce the demands on the remote meter station transceiver as compared to those on the central control unit transceiver. The bit clock at the central control unit and the meter stations is derived from the 60-Hz power line phase available at each station. Each meter station achieves message synchronization by continuously monitoring the data bit stream for a preset synchronization code and thereafter treats the following 21 data bits as address and function codes.