Laser ablation solid sampling: Vertical spatial emission intensity profiles in inductively coupled plasma

Spectral emission intensity in the inductively coupled plasma (ICP) was measured versus height above the load coil during laser ablation solid-sample introduction. The laser-beam pulse width, power density, and wavelength, and the sample composition are know to effect the particle size distribution of the ablated mass. Ceramic and metal samples were ablated using nanosecond and picosecond pulses, and provided similar emission intensity profiles for common elements, indicating that changes in the particle size distribution are not manifested in the vertical spatial emission profile. The gas environment in the ablation chamber also influences the particle size distribution as well as the ablation interaction. Gas composition will influence the spatial emission intensity profile because of changes in the excitation characteristics of the ICP. A preliminary study using noble gases in the ablation interaction was conducted by keeping the spatial profile constant, maintaining a constant total gas composition to the ICP.

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