(Typomorphic features of celadonite structure.

The 1M celadonite from ferruginous metasomatic silicate rocks of the Krivoi Rog, Ukraine, has a high Fe3+ content in the octahedral layer, with a 5.21-5.23, b 9.03-9.05, c 10.10-10.15 A, beta 100o30'-100o50'. This presence of Fe3+ in the octahedral layer determines the unique structure of the dioctahedral phyllosilicates. The degree of structural perfection of celadonite is a sensitive indicator of the conditions of crystallization. -R.A.H

(Typomorphic features of celadonite structure.

The 1M celadonite from ferruginous metasomatic silicate rocks of the Krivoi Rog, Ukraine, has a high Fe3+ content in the octahedral layer, with a 5.21-5.23, b 9.03-9.05, c 10.10-10.15 A, beta 100o30'-100o50'. This presence of Fe3+ in the octahedral layer determines the unique structure of the dioctahedral phyllosilicates. The degree of structural perfection of celadonite is a sensitive indicator of the conditions of crystallization. -R.A.H

Optical-acoustic effect in laser optics investigations

Parameters of the acoustic signals (AS) excited in the massive Al, Be and Cu mirrors by TEA CO2- and Nd : glass-laser pulses were investigated. Correlations between the AS parameters and an emergence of different types of laser-induced damage such as evaporation of heat insulated defects, melting and optical breakdown off irradiated surface have been found. The possibility to make a nondisturbing prediction of the metal mirror resistance to laser-induced damage has been shown

Optical-acoustic effect in laser optics investigations

Parameters of the acoustic signals (AS) excited in the massive Al, Be and Cu mirrors by TEA CO2- and Nd : glass-laser pulses were investigated. Correlations between the AS parameters and an emergence of different types of laser-induced damage such as evaporation of heat insulated defects, melting and optical breakdown off irradiated surface have been found. The possibility to make a nondisturbing prediction of the metal mirror resistance to laser-induced damage has been shown.Les paramètres des signaux acoustiques générés par des impulsions de lasers TEA-CO2 et Nd-glass dans des miroirs massifs en Al, Be et Cu ont été étudiés. Nous avons trouvé des corrélations entre les signaux acoustiques et l'apparition de dommages variés induits par laser tels que l'évaporation de défauts isolés thermiquement, la fusion et le breakdown optique des surfaces illuminées. La possibilité de faire une prédiction non destructive de la résistance de miroirs métalliques à l'endommagement laser est démontrée