Abstract: A modular assembly for a bulk material includes container modules defining at least one radiation source cavity, at least one radiation detector channel and a passageway disposed for enabling passage of the conveyor belt through an activation region; and radiation shielding material disposed within the container means. A lower primary module contains a first portion of the radiation shielding material and defines either the radiation source cavity or the radiation detector channel. An upper primary module contains a second portion of radiation shielding material and defines the other of either the radiation source cavity or the radiation detector channel. A set of replaceable side modules contain additional portions of the radiation shielding material.

Abstract: In a bulk material analyzer in which bulk material is received in an activation region between a pair of neutron sources laterally disposed on one side of the activation region for emitting neutrons for bombarding the bulk material within the activation region to cause gamma-rays to be emitted from the bombarded bulk material and a pair of gamma-ray detectors laterally disposed on an opposite side of the activation region for detecting gamma-rays emitted from the bulk material, and in which a neutron moderator is disposed between the neutron sources and the activation region for reducing the velocity of the emitted neutrons such that the neutrons entering the activation region include thermal neutrons and faster neutrons, the uniformity of sensitivity of the bulk material analyzer to materials at different positions in a sample of the bulk material being analyzed is enhanced by controlling the proportions of thermal neutron at different positions within the sample being analyzed.

Abstract: A hydroball string sensing system for a nuclear reactor that includes stainless tubes positioned to guide hydroball strings into and out of the nuclear reactor core. A sensor such as an ultrasonic transducer transmitter and receiver is positioned outside of the nuclear reactor core and adjacent to the tube. The presence of an object such a bullet member positioned at an end a hydroball string, or any one of the hydroballs interrupts the transmission of ultrasound from the transmitter to the receiver. Alternatively, if the bullet member and hydroballs include a ferritic material, either a Hall effect sensor or other magnetic field sensors such as a magnetic field rate of change sensor can be used to detect the location and position of a hydroball string. Placing two sensors along the tube with a known distance between the sensors enables the velocity of a hydroball string to be determined.

Abstract: The work is scanned by acoustic energy from a focused-arc transducer and from an acoustic-lens transducer. An echo-ranging subassembly energizes the focused-arc transducer and processes the echo trains relfected from the lines or pencils in the work along which the acoustic energy is focused. A holographic echo-processing subassembly is connected to energize the acoustic-lens transducer and to process the echoes reflected from the work where the energy from the acoustic lens impinges. The echo-ranging subassembly and the holographic echo-processing subassembly are enabled alternately and the acoustic energy from the focused-arc transducer and from the acoustic-lens transducer impinge on, and is reflected by, each of a succession of elemental areas of the work. The outputs of the echo-ranging subassembly and of the holographic echo-processing subassembly are supplied to an elastic store which may include one or more shift registers.

Abstract: Echo ranging flaw detecting, characterizing and studying apparatus in which the work is scanned simultaneously by acoustic energy focused at a point from an acoustic-lens transducer and by acoustic energy focused along a line along which it is propagated from a focused-arc transducer. The acoustical echos from the lens transducer are combined with an electrical analog of an acoustical reference wave to produce an acoustical interference pattern which is reconstructed into a holographic display or hologram by a laser beam. The echos from the focused-arc transducer produce a cathode-ray tube display or are stored in a memory.

Abstract: In detecting, characterizing or studying flaws in work whose surface is irregular by acoustic imaging in which a holographic pattern is produced the irregular surface is scanned by acoustic energy focussed on or near the irregular surface and the reception of the acoustic energy resulting from echoes from flaws is controlled for each scanned elemental area so as to reduce to a negligible magnitude the effects or variations in the acoustical path caused by the irregularties at different elemental areas in accordance with the irregularity at that area. The control may be effected by filling in the depressions in the irregular surface with an acoustic energy absorbing material such as butyl rubber or with a material, such as wax, which is not wetted by the liquid through which the acoustic energy is propagated to the surface.

Abstract: A method for altering the lateral dimension of the focal zone produced by an integral ultrasonic lens system. The method comprises the steps of removing a volume of lens material from the integral lens system so as to define two separate and distinct remainder volumes on each side of the removed volume. The remainder volumes are then laterally or rotationally displaced relative each other to alter the lateral dimension of the focal zone produced by the integral lens or to produce a discrete focal zone for each of the remaining lens volumes.

Abstract: An acoustic imaging system utilizing an acoustic lens and a transducer array. A corrector device is placed in front of the transducer array to flatten the image field so as to conform to the surface of the transducer array.

Abstract: An acoustic transducer-reflector using a single disc-shaped piezoceramic element radiating into a compound reflector for obtaining a line focus sound beam that is characteristic of focused-arc transducers that maybe used for underseas applications and for non-destructive materials testing. The single transducer emits acoustic energy into the compound reflector which reshapes a circular beam into a focused arc beam. A shadow mask or aperture stop positioned in front of the reflector assures a beam such as would be radiated from a ring source.