[en] A method has been described for the noncontact ultrasonic imaging of subsurface defects, using a concentric pulsed laser-annular Electromagnetic Acoustic Transducer (EMAT) system. The linear scane data of this system were processed to reconstruct images using the two-dimensional Synthetic Aperture Focussing Technique (SAFT). The result show that this system can accurately be used for imaging by slightly modifying the basic SAFT algorithm. (author). 18 refs, 10 figs
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[en] A q-switched ruby laser ultrasonic source concentric with an annular electro-magnetic acoustic transducer (EMAT) as a detector, working in a pulsed-echo system, have been used to inspect titanium diffusion bonds for nuclear reactor spent fuel containers. The detected waveforms were analyzed with cepstral analysis to indicate the effectiveness of diffusion bonding. The results show that they are in good agreement with those of the conventional immersion testing. (authors). 20 refs, 8 figs
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[en] A method has been described for the noncontact ultrasonic thickness measurements of thin aluminium sheets, using a Q-switched ruby laser generation concentric with an annular electro-magnetic acoustic transducer (EMAT) detection to imitate pulse-echo system. The detected waveforms were analyzed with the cut-off frequences of the higher order lamb modes. The results show in a good egreement with micrometer measurements within 2% discrepancy. (authors). 22 refs, 6 figs
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