Abstract
Streak photography, visible-UV emission spectroscopy, infrared emission and time-integrated photography have been used to study the laser ablation of Y--Ba--Cu--O in an oxygen environment. At O sub 2 pressures = > 1 mbar, the dynamics of the plume become relatively complex, with the expansion resemblying a blast-wave with strong mixing and reaction at the contact surface. The range of the ablated material has been measured and compared with an adiabatic expansion model which gives a reasonable description of the results. Preliminary experiments suggest that the quality of deposited films is critically dependent upon the relative position of substrates with respect to the plume range. Graphs, Photomicrographs. 16 ref.--AA