Energy balance of a laser ablation plume expanding in a background gas

Abstract

The energy balance of a laser ablation plume in an ambient gas for nanosecond pulses has been investigated on the basis of the model of Predtechensky and Mayorov (PM), which provides a relatively simple and clear description of the essential hydrodynamics. This approach also leads to an insightful description in dimensionless units of how the initial kinetic energy of the plume is dissipated into kinetic and thermal energy of the background gas. Eventually when the plume has stopped, the initial kinetic energy of the plume is converted into thermal energy of the plume and background gas.

On the role of the ablated mass on the propagation of a laser-generated plasma in an ambient gas

“…A scattering formalism [7,11] is appropriate to describe the complex plume dynamics, in particular when splitting is observed at specific distances and pressures, yet simpler hydrodynamic models retain their validity at the expense of a less accurate description of plume propagation [12][13][14]. The relation between ablated mass per pulse (M P ) and gas mass is a critical parameter that severely affects the different plasma expansion regimes and the corresponding plasma-gas energy exchange [15][16][17]. While the gas mass is determined by the pressure in the deposition chamber, the ablated mass is not unequivocally determined by the laser fluence (f L ), as obtained from the ratio between the laser pulse energy and the area of the (usually) focused laser spot on the target surface.…”

Critical influence of target-to-substrate distance on conductive properties of LaGaO3/SrTiO3 interfaces deposited at 10−1 mbar oxygen pressure

“…[13][14][15][16][17][18][19][20] As observed above, the confining effect of the background gas leads to a progressive reduction of the plume kinetic energy. This, indeed, is accompanied by a gradual conversion of such an energy into an excess of internal energy of the plume and background gas.…”

“…This, indeed, is accompanied by a gradual conversion of such an energy into an excess of internal energy of the plume and background gas. 16,20 This, in turn, results in a larger content of excited species which can be considered as a qualitative figure of the plume internal energy. As an example, Fig.…”