A STUDY OF LASER-PRODUCED COPPER PLASMA AT REDUCED PRESSURE FOR SPECTROSCOPIC APPLICATIONS

The aim of this work is to specify experimental conditions which allow atomic emission with the finest possible linewidths to be obtained in a laser-produced copper plasma at reduced pressure (20 mTorr). For the initial stage of the plasma evolution (t < 1 mu s) a three-dimensional expansion description of the plasma plume is developed by means of pictures taken with a gated and Intensified Charge-Coupled Device (ICCD) camera. Full linewidths and line intensities of investigated copper transitions obtained by high-resolution spectrometry are related to the spatial position in the plasma plume with this mapping. The influence of different relevant plasma parameters on the linewidth as well as its space and time evolution is discussed. Best values of full linewidths of 0.1 Angstrom were obtained for the CuI transition 5105 Angstrom.