LOW TEMPERATURE ULTRASONIC ATTENUATION IN NEUTRON-IRRADIATED QUARTZ VERSUS THE INDUCED MASS-DENSITY CHANGES A. VANELSTRAETE, C. LAERMANS et J. CORNELIS J. Phys. Colloques, 48 C8 (1987) C8-531-C8-537 DOI: 10.1051/jphyscol:1987883