Laser-induced Breakdown Spectroscopy; Atomic Spectroscopy; Molecular Spectroscopy; Laser Ablation; 'lime-resolved Spectroscopy; Spectroscopy in Chemical Analysis;INDUCED BREAKDOWN SPECTROSCOPY; LINES; DENSITY; SPECTRA

This article gives a brief review of experimental studies of hydrogen Balmer series emission spectra. Ongoing research aims to evaluate early plasma evolution following optical breakdown in laboratory air. Of interest is as well laser ablation of metallic titanium and characterization of plasma evolution, Emission of titanium monoxide is discussed together with modeling of diatomic spectra to infer temperature. The behavior of titanium particles in plasma draws research interests ranging from the modeling of stellar atmospheres to the enhancement of thin film production via pulsed laser deposition,

ELECTRON NUMBER DENSITY; TEMPORAL EVOLUTION; ABEL-INVERSION; AIR; BREAKDOWN

Microplasma is generated in an ultra-high-pure H-2 and N-2 gas mixture with a Nd:YAG laser device that is operated at the fundamental wavelength of 1064 nm. The gas mixture ratio of H-2 and N-2 is 9 to 1 at a pressure of 1.21 +/- 0.03 10(5) Pa inside a chamber. A Czerny-Turner-type spectrometer and an intensified charge-coupled device are utilized for the recording of plasma emission spectra. The line-of-sight measurements are Abel inverted to determine the radial distributions of electron number density and temperature. Recently derived empirical formulas are utilized for the extraction of values for electron density. The Boltzmann plot and line-to-continuum methods are implemented for the diagnostic of electron excitation temperature. The expansion speed of the plasma kernel maximum electron temperature amounts to 1 km/s at a time delay of 300 ns. The microplasma, initiated by focusing 14 ns, 140 mJ pulses, can be described by an isentropic expansion model. (C) 2017 Optical Society of America

URANIUM; LIBS; FLUORESCENCE; SPECTROMETRY; MATRICES; SAMPLES; SYSTEM; PULSE; UF6

A hand-held device for laser-induced breakdown spectroscopy has been investigated for the determination of uranyl fluoride surface contamination. This research demonstrates the ability to successfully detect uranium on surfaces when using a low resolving power (lambda/Delta lambda = 4000) spectrograph, with a 5 mJ energy per 1 ns pulsed laser radiation, available as a commercially packaged hand-held system. Sand/uranyl fluoride mixtures are prepared to simulate residue likely encountered during decontamination efforts at facilities that handle uranium hexafluoride. Detection limits are described for four uranium lines with one revealing the capability to detect uranium at a level of 250 parts per million. Advantages of the studied compact device include that location specific information can be obtained on-site to augment contamination identification. (c) 2017 Optical Society of America

Laser-induced breakdown spectroscopy; LIBS; Polyethylene; Rubber from tire production; Molecular emission spectroscopy; Rotational-vibrational analysis;