Abstract: A probe capable of inducing a rotating magnetic field to excite a conductive tube includes an array of magnetic field sensors to detect and characterize defects in the tube. The probe includes a circumferential coil assembly and an axial coil assembly both positioned to induce eddy currents in the conductive tube, such that the magnetic field sensors can detect defects in the tube, including defects extending circumferentially, axially, or any combination thereof, whether at the surface or sub-surface of the tube inner and outer walls.

Abstract: A rotating magnetic field probe includes three (or more) windings that work in both transmit and receive mode, to form an eddy current detection transceiver. In a transmit mode, the windings are driven with a drive signal (e.g., an alternating current) having similar or the same magnitude at each winding, but differing in phase from one another. In a receive mode, the terminal voltages of the windings is measured and summed to determine the location of a defect.

Abstract: A probe capable of inducing a rotating magnetic field to excite a conductive tube includes an array of magnetic field sensors to detect and characterize defects in the tube. The probe includes a circumferential coil assembly and an axial coil assembly both positioned to induce eddy currents in the conductive tube, such that the magnetic field sensors can detect defects in the tube, including defects extending circumferentially, axially, or any combination thereof, whether at the surface or sub-surface of the tube inner and outer walls.

Abstract: A rotating magnetic field probe includes three (or more) windings that work in both transmit and receive mode, to form an eddy current detection transceiver. In a transmit mode, the windings are driven with a drive signal (e.g., an alternating current) having similar or the same magnitude at each winding, but differing in phase from one another. In a receive mode, the terminal voltages of the windings is measured and summed to determine the location of a defect.

Abstract: A tomographic imaging system comprising a source array emitting rays, a deformable mirror reflecting the rays emitted by the source array, and a detector array receiving the electromagnetic rays emitted by the source array and reflected by the deformable mirror. An object can be positioned between the deformable mirror and the detector array and the deformable mirror can be deformed to a plurality of configurations to form a tomographic image of the object. The system can also be used in radiation therapy.

Abstract: A tomographic imaging system comprising a source array emitting rays, a deformable mirror reflecting the rays emitted by the source array, and a detector array receiving the electromagnetic rays emitted by the source array and reflected by the deformable mirror. An object can be positioned between the deformable mirror and the detector array and the deformable mirror can be deformed to a plurality of configurations to form a tomographic image of the object. The system can also be used in radiation therapy.

Abstract: An optoelectronic tomographic reconstruction system utilizes spacial light modulators in charge couple devices to perform projection iterative reconstruction techniques and simultaneous iterative reconstruction techniques. A back projection processor uses a linear array of analog spacial light modulators in a cylindrical lens, an image detection array, and an image rotator. The image rotator smears a projected image at the same angle as the projection was taken. The back projection processor thus smears the projection back to the image space. An optoelectronic forward projection processor uses an spacial light modulator array, an image rotator, and an image detecting array. A reconstructed image displayed by the spacial light modulator is smeared by the rotator to forward project the reconstructed image on the image detecting array at the same angle as when the measured projection was taken. The forward projection processor thus smears the reconstructed image back into the projection space.

Abstract: A method and apparatus for electronically driving an ultrasonic acoustic transducer. The transducer is operable in two modes; in a first mode, the lock-in frequency of the transducer is determined; in a second mode, the lock-in frequency determined in the first mode is used to modulate a tone-burst pulse to drive the transducer in an efficient manner. Operating in the first mode, the lock-in frequency is determined by exciting the transducer with a series of tone bursts, where each tone burst comprises an electronic pulse modulated by a tone of one frequency selected from a range of frequencies, and measuring the response of the transducer to each tone burst. In an alternative embodiment, the excitation of the transducer in the first mode is provided by a signal whose frequency is swept over a range. The response of the transducer is sampled at various times during the sweep. The lock-in frequency is chosen by examining the responses and choosing the frequency which gives the best response.

Abstract: An optoelectronic tomographic reconstruction system utilizes spacial light modulators in charge couple devices to perform projection iterative reconstruction techniques and simultaneous iterative reconstruction techniques. A back projection processor uses a linear array of analog spacial light modulators in a cylindrical lens, an image detection array, and an image rotator. The image rotator smears a projected image at the same angle as the projection was taken. The back projection processor thus smears the projection back to the image space. An optoelectronic forward projection processor uses an spacial light modulator array, an image rotator, and an image detecting array. A reconstructed image displayed by the spacial light modulator is smeared by the rotator to forward project the reconstructed image on the image detecting array at the same angle as when the measured projection was taken. The forward projection processor thus smears the reconstructed image back into the projection space.

Abstract: Apparatus for detecting surface flaws in cylindrical articles having central longitudinal axes, including a guide assembly for guiding the cylindrical articles along a displacement path having a central longitudinal axis extending coaxially of the central longitudinal axes of the articles and a detection coil assembly positioned in annular relationship with the displacement path for producing a signal representative of the surface geometry of a cylindrical article which traverses the displacement path.