ULTRASONIC ATTENUATION STUDY OF THE INTERACTION OF IRRADIATION PRODUCED PINNING POINTS WITH DISLOCATIONS IN COPPER A. OSTERMANN, D. LENZ et K. LÜCKE J. Phys. Colloques, 32 C2 (1971) C2-149-C2-150 DOI: 10.1051/jphyscol:1971232