TY - CONF A1 - Shcheglov, Pavel A1 - Gumenyuk, Andrey A1 - Gornushkin, Igor B. A1 - Rethmeier, Michael T1 - Experimental investigation of the laser-plume interaction during high power fiber laser welding N2 - The effect of the well-known plasma absorption and refraction in CO2-laser metal welding plumes is in case of high power solid state laser welding negligibly small. By contrast, the diffraction effects of shorter wavelength laser radiation are considerable. According to the results of preliminary studies, the fine condensed metal particles in the welding plume can lead to essential worsening of the laser beam quality. This work is devoted to the investigation of the lasermatter interaction during up to 20 kW ytterbium fiber laser welding of thick mild steel plates. The plume attenuation of a probe 1.3 µm wavelength diode laser beam as well as of continuous radiation in 250-600 nm wavelength range was measured during welding with and without Ar shielding gas supply. The measured results allow it to calculate average size and concentration of fine condensed metal particles in different plume areas using the multi-wavelength method and the Mie scattering theory. The plume temperature, which determines the condensation conditions, was measured by means of Fe I atom spectral line emission registration. The obtained results can be also of interest for remote metal treatment with high-power fiber or disc lasers. T2 - 30th ICALEO - International congress on applications of lasers & electro-optics CY - Orlando, FL, USA DA - 2011-10-23 PY - 2011 SN - 978-0-912035-94-9 SP - Paper 1606, 637 EP - 645 AN - OPUS4-24921 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. A1 - Shabanov, Sergej V. A1 - Merk, Sven T1 - Interplay between Diagnostic and Modeling in Laser Induced Breakdown Spectroscopy T2 - CSI37 - Colloquium Spectroscopicum Internatione XXXVII CY - Búzios, Brazil DA - 2011-08-28 PY - 2011 AN - OPUS4-24879 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. A1 - Nagli, L. A1 - Gaft, M. T1 - Fraunhofer Lines in Double Pulse Laser Induced Plasma T2 - NASLIBS 2011 CY - Clearwater, FL, USA DA - 2011-07-18 PY - 2011 AN - OPUS4-24883 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. A1 - Heitmann, U.M. A1 - Müller, Maike A1 - Smith, B.W. A1 - Omenetto, N. A1 - Winefordner, J. D. T1 - Evaluation of optical thickness of laser induced plasma by duplication factor approach T2 - FACSS 2006 CY - Orlando, FL, USA DA - 2006-09-24 PY - 2006 AN - OPUS4-16479 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. A1 - Heitmann, U.M. A1 - Smith, B.W. A1 - Omenetto, N. A1 - Winefordner, J. D. A1 - Müller, Maike T1 - Analysis of cast Iron bx Laser Induced breakdown spectroscopy using ortogonal pre-ablation spark and high-resolution echelle spectrometer T2 - FACSS 2006 CY - Orlando, FL, USA DA - 2006-09-24 PY - 2006 AN - OPUS4-16480 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. T1 - Laser induced plasmas: prediction of plasma composition T2 - FACSS 2008 CY - Reno, NV, USA DA - 2008-10-27 PY - 2008 AN - OPUS4-18529 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. T1 - Laser Induced Plasma Modeling: Implications for Spectrochemical T2 - LIBS 2008 CY - Berlin, Germany DA - 2008-09-22 PY - 2008 AN - OPUS4-18531 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shcheglov, Pavel A1 - Gumenyuk, Andrey A1 - Gornushkin, Igor B. A1 - Rethmeier, Michael A1 - Petrovskiy, V.N. T1 - Vapor-plasma plume investigation during high-power fiber laser welding N2 - This work is devoted to the investigation of the laser–matter interaction during up to 20 kW ytterbium fiber laser welding of thick mild steel plates. The plume attenuation of a probe 1.3 µm wavelength diode laser beam as well as of continuous radiation in the 250–600 nm wavelength range was measured during welding with and without Ar shielding gas supply. The measured results allow the calculation of the average size and concentration of fine condensed metal particles in different plume areas using the multi-wavelength method and the Mie scattering theory. The plume temperature, which determines the condensation conditions, was measured by means of Fe I atom spectral line emission registration. The spatial distribution of the extinction coefficient in the welding plume was measured and the plume attenuation of the high-power fiber laser beam during the welding process was estimated. PY - 2013 DO - https://doi.org/10.1088/1054-660X/23/1/016001 SN - 1054-660X SN - 1531-8494 VL - 23 IS - 016001 SP - 1 EP - 7 PB - MAIK Nauka/Interperiodica Publ. CY - Moscow AN - OPUS4-27280 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shabanov, Sergej V. A1 - Gornushkin, Igor B. T1 - Absorption tomography of laser induced plasmas N2 - An emission tomography of laser-induced plasmas employed in the laser induced breakdown spectroscopy (LIBS) requires signal integration times in a microsecond range during which the LIBS plasma cannot be considered stationary. Consequently, the use of the data for reconstructing the plasma properties under the assumption that the latter does not change significantly during the integration time leads to inaccurate results. To reduce the integration time, it is proposed to measure a plasma absorption in parallel rays using a scanning rectangular aperture whose dimension Δ along the scanning direction is about a characteristic size of plasma plumes (Δ ~ 1 cm) and the other dimension Δp is of the order of a uniformity length of plasma parameters (Δp ~ 10 µm). The aperture is moved step by step along the scanning direction and the total energy of photons coming through the aperture is measured during time T at each position of the aperture. Owing to the large size of the aperture, the integration time T is reduced by a factor ~ Δp/Δ. A numerical data processing is proposed to restore the spatial resolution of the plasma absorption along the scanning direction. It is determined by the scanning step Δs ≤ Δp. Another advantage of the proposed procedure is that inexpensive linear CCD or non-discrete (PMT, photodiode) detectors can be used instead of costly 2-dimensional detectors. KW - Plasma tomography KW - Laser induced plasma PY - 2012 DO - https://doi.org/10.1016/j.jqsrt.2011.12.016 SN - 0022-4073 VL - 113 IS - 7 SP - 518 EP - 523 PB - Pergamon Press CY - Oxford [u.a.] AN - OPUS4-25823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gaft, M. A1 - Nagli, L. A1 - Gornushkin, Igor B. A1 - Groisman, Y. T1 - Doubly ionized ion emission in laser-induced breakdown spectroscopy in air N2 - The emission from doubly ionized species in laser-induced plasmas has not been properly investigated before since most analytical measurements were made at relatively long delays. This work proves that doubly ionized species, such as boron (B) III and iron (Fe) III, can exist during the first 150–200 ns of the plasma lifetime in plasmas produced in air by typical lasers with irradiances of 109 1011 W/cm². The emission from these ions was detected using both the double- and single-pulse excitations. The sum of the second ionization potential and the energy of corresponding excited states is approximately 30 eV. The presence of doubly charged ions in the early plasma was additionally confirmed by computer simulations using a collision-dominated plasma model. The Emission from doubly ionized species may be used for analytical purpose. For example, in the spectrum from a B–Fe ore, the B III analytical line at 206.6 nm is free from Fe spectral interference thus enabling the online laser-induced breakdown spectroscopy sorting of ores into three products with high, medium, and low B2O3 contents. KW - Plasma KW - Double ionization KW - Boron KW - Iron KW - Online KW - Sorting PY - 2011 DO - https://doi.org/10.1007/s00216-011-4847-0 SN - 1618-2642 SN - 1618-2650 VL - 400 IS - 10 SP - 3229 EP - 3237 PB - Springer CY - Berlin AN - OPUS4-25825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -