Energy release in processing of tantalum with nanosecond Nd:glass laser pulse

The total energy involved in the interaction of nanosecond Nd:glass laser pulses with tantalum in oxygen at pressures of 760 Torr and 1 Torr has been investigated experimentally in the range of laser fluences between 0.05 and 6 J/cm/sup 2/. It was found that for interactions in the range of laser fluences below 0.08 J/cm/sup 2/, the total energy is equal to the energy of the laser pulse. At laser fluences above 0.08 J/cm/sup 2/, a release of additional energy was observed at both oxygen pressures. The estimated contribution of chemical energy produced by the formation of tantalum pentoxide is not sufficient for the explanation of the observed additional energy release.