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STUDY OF LASER ABLATION OF GRAPHITE-POLYMER AND POLYMER TARGETS USING CAVITY RING-DOWN

We performed laser ablation of different graphite-polymer (PPS) and polymer (Mylar type A), means of a pulsed laser (XeCl, 308 nm, 15 ns). Laser fluence was about 1 J/cm2. The target was avoid drilling. Induced plume is allowed to spread in vacuum at pressure of about 10– 3 mbar. used cavity ring-down spectroscopy for absorption measurements in the plume within the spectral 450-480) nm. The C2 radicals were detected through the observation of Swan bands. simulation of absorption spectra was used for determination of vibrational and rotational temperatures. Comparing to pure graphite laser ablation, much higher ro-vibrational temperatures were observed case of graphite-PPS target. In addition, observed C2 density decreases as number of increases, contrary to the case of laser ablation of pure graphite targets. In the case of pure polymer ablation, C2 observation was possible only in the very early time windows (fast radicals). periods, scattering on large (slow) particles gives dominant contribution to the cavity loss. for monitoring of polymer laser ablation by means of the cavity ring-down spectroscopy methods, such as optical emission spectroscopy will be discussed.

laser ablation; graphite; polymers; absorption spectroscopy; cavity ring-down

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