[en] In this study K-beta/K-alpha (K_β/K_α) intensity ratios of the elements scandium (Sc), vanadium (V), chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), bromine (Br), yttrium (Y), zirconium (Zr), and niobium (Nb) have been measured at three azimuthal scattering angles (+30^o, 0^o, and -30^o) for two fixed polar scattering angles (85^o and 135^o). The elements were excited by 59.54 keV gamma photons emitted from 100 mCi Am²⁴¹ point source. The obtained experimental values were compared with the theoretical values presented in the literature. It is observed that (K_β/K_α) intensity ratios of the investigated elements do not depend on azimuthal angles at fixed polar angles. (author)

[en] Measurements of the rotational temperature of molecular nitrogen by emission spectroscopy were performed in a dc plasma torch of non-transferred arc operating at three different output powers. The band (0, 1) of the first negative system of N₂⁺ (B²Σ_u⁺→X²Σ_g⁺) for the R branch was selected for these studies.

No abstract available

[en] In this work different projects in the field of inductively-coupled plasma optical emission spectrometry (ICP-OES) are presented. The first part deals with sample preparation. A new approach for microwave-assisted high pressure flow digestion was investigated and, in addition, diesel samples were digested using microwave-induced combustion for the subsequent determination of sulfur. In the second part a newly constructed optical interface for ICP-OES was designed which seals the plasma from the surroundings. This makes it possible to recycle part of the plasma gases leading to high savings of running costs. Furthermore, novel insights into the so-called 'carbon enhancement effect' are given. (author)

[en] Statistical uncertainty in the quantitative analysis of solid samples in motion by laser-induced breakdown spectroscopy (LIBS) has been assessed. For this purpose, a LIBS demonstrator was designed and constructed in our laboratory. The LIBS system consisted of a laboratory-scale conveyor belt, a compact optical module and a Nd:YAG laser operating at 532 nm. The speed of the conveyor belt was variable and could be adjusted up to a maximum speed of 2 m s^-1. Statistical uncertainty in the analytical measurements was estimated in terms of precision (reproducibility and repeatability) and accuracy. The results obtained by LIBS on shredded scrap samples under real conditions have demonstrated that the analytical precision and accuracy of LIBS is dependent on the sample geometry, position on the conveyor belt and surface cleanliness. Flat, relatively clean scrap samples exhibited acceptable reproducibility and repeatability; by contrast, samples with an irregular shape or a dirty surface exhibited a poor relative standard deviation.

[en] Published in summary form only

[en] Thermoluminescence (TL) emission spectra have been obtained from alkali feldspars ranging from monoclinic and triclinic potassium-rich feldspars to tricline sodium-rich feldspars, as well as from a synthetic gel of KA1Si₃O₈ composition. Emissions were detected in the wavelength range 200-800 nm using a high sensitivity spectrometer. The results suggest that the 290 nm emission band in TL is associated either with the presence of crystalline phases of NaA1Si₃O₈ or with Na/K exsolution interfaces. (author)

[en] Published in summary form only

[en] The excitation dynamics of a micro-structured plasma channel device with an inverted equilateral triangular cross-section are investigated. This device is operated in argon close to atmospheric pressure with an ac voltage. It is characterized by means of electrical measurements and optical emission spectroscopy. One emission phase is observed in each half-cycle of the applied voltage waveform. Each shows self-pulsing of the device. The integrated intensities for both phases differ by a factor of about two. Phase-resolved wavelength-integrated optical emission spectroscopy which resolves the intensity profile of the plasma channel reveals clear differences between positive and negative half period. Emission features propagating along the discharge channel at velocities of a few km s^-1 are observed. Discharge dynamics are compared with those reported for micro-structured atmospheric pressure plasma arrays with discharge cavities of similar triangular cross-section. The comparison allows conclusions on the interaction of individual inverted pyramidal cavities.

No abstract available