STP716: Sensitivity of High-Energy Real-Time Radiography with Digital Integration

    Sklensky, AF
    Research scientist and manager, Lockheed Research Laboratories, Palo Alto, Calif.

    Buchanan, RA
    Research scientist and manager, Lockheed Research Laboratories, Palo Alto, Calif.

    Pages: 15    Published: Jan 1980


    Abstract

    The use of a Lockheed-designed digital integrator has allowed high-energy real-time radiography to challenge the image quality of film. The integrator is a device that digitally sums television (TV) frames or effectively increases the exposure time. The integrator is being used as part of a high-energy radiography system that typically uses a 15-MeVp radiation source to penetrate the absorber, for example, 1.5 m (5 ft) of propellant. The real-time X-ray camera converts the X-ray image into an electronic signal in standard TV format. The TV frames are fed to the integrator. The high image quality of the Lockheed integrator results from the large memory used, precise timing, equal weighting of the frames, and the capability for repetitive integration. The nominal 512-by-512 pixel array and the precise timing give high resolution. Eight-bit digitization into and out of the integrator reduces digitization noise well below the eye's threshold for detection. The nominal 9-min-maximum integration time permits radiography through extremely thick absorbers or with low-flux sources. The presence of a refresh memory permits the inspection of a full-quality image while the remainder of the memory is being used to integrate a new frame. It also makes possible repetitive integration, which makes integration of radiographs of objects in motion feasible. Finally, image subtraction permits the removal of system anomalies or image gradients or both.

    Keywords:

    nondestructive testing, real-time radiography, image processing, high-energy radiography, low-light-level television, radiography


    Paper ID: STP27516S

    Committee/Subcommittee: E07.11

    DOI: 10.1520/STP27516S


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