Characterization of gadolinium via the temporal and spatial evolution of emissions from laser-created plasmas

Summary form only given. Atomic emission spectroscopy of laser generated plasmas can be used to analytically detect elements at ppm concentrations in harsh or radioactive environments. In this technique, a laser beam is focused onto the surface of a sample, the sample is vaporized and a high-temperature plasma is formed. Spectral analysis of the plasma light yields a determination of the elemental content of the original sample. Because the constituents of the laser-created plasma are not constant in time, time-resolved spectral analysis, whereby spectra are obtained only during a specified period of time following creation of the plasma, allows one to discern atomic emissions from ionic emissions and to improve signal-to-noise ratios because the initial large background can be eliminated from detection. A further characterization of the laser generated plasma is obtained by studying its spatial evolution, and is accomplished using a gated, two-dimensional detector, which allows the time-resolved spectroscopic image of the plasma plume to be captured. We chose gadolinium (Gd) for our experiments because many of its physical properties.