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Laboratory of Laser Techniques, Institute of Physics, University of Tartu. Aleksei Treshchalov atr@fi.tartu.ee Riia str 142, 51014, Tartu, ESTONIA , http://www.fi.ut.ee/en/lasertehnika-labor. Studied topics
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Laboratory of Laser Techniques, Institute of Physics, University of Tartu Aleksei Treshchalov atr@fi.tartu.ee Riia str 142, 51014, Tartu, ESTONIA, http://www.fi.ut.ee/en/lasertehnika-labor • Studied topics • WG 4 Interaction of plasma reactive species with different targets for specific applications. • Plasma-assisted synthesis of nanomaterials in gases and liquids. • High-pressure pulsed discharges in gas jets. • Nanosecond time-resolved VUV-VIS spectroscopic (imaging) diagnostics of the discharge with the aim to clarify and optimize the energy flow kinetics in plasma during all stages of nanofabrication (excitation, nucleation and growth). Differential mobility analyzer (DMA, designed in Tartu University) for on-line detection of the diameter of charged and neutral nanoparticles. Diagnostics setup for time-resolved VUV-VIS spectroscopy of plasma. • Main experimental/computational facilities • VUV (112-350 nm) and UV-VIS (200-850 nm) spectrometers with ns-gated ICCD cameras,digital oscilloscope (500 MHz) for time-resolved acquisitions, excimer lasers (XeCl, ArF, F2), tunable dye lasers (250-850 nm). • Differential mobility analyzer (DMA), 0.8 -40 nm for charged and 2-40 nm for neutral nanoparticles; scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy.
Main research collaborations and industrial partners • ESTLA, small company in the field of laser technology, http://www.estla.com/ • Estonian Nanotechnology Competence Center, encc.ee Main publications • Treshchalov, A.; Lissovski, A.; Ulrich, A. (2013). Light emission from heteronuclear Ar-Kr doubly ionized excimer molecules. The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics, 67(2), 1 - 6. • Treshchalov, A.; Lissovski, A. (2012). Multi-band spectral structure and kinetics of the third continua in Ar, Kr and Xe gases excited by a pulsed discharge. The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics, 66(4), 95 - 103. • Shulga, E; Pohako, K; Treshchalov, A; Joost, U; Kisand, V; Kink, I (2011). Functionalisation of aligned carbon nanotubes with nitric acid vapour. Micro & Nano Letters, 6(8), 704 - 708. • Lissovski, A; Treshchalov, A. (2009). Emission of the third continuum of argon excited by a pulsed volume discharge. Physics of Plasmas, 16(12), 123501 • Treshchalov, A.; Lissovski, A. (2009). VUV-VIS spectroscopic diagnostics of a pulsed high-pressure discharge in argon. Journal of Physics D: Applied Physics, 42, 245203 Size distribution (0.8–40 nm) of the chargedCu particles, at the output of the alumina tube (low-current discharge in He). Reactor for generation of size-controlled nanoparticles in cathode spots of pulsed discharges. Cathode materials: Cu, Au, Ti, W, Fe… and alloys. He, Ar gases - metal nanoparticles. N2 (O2) additives –metal nitrides(oxides)nanoparticles. Size distribution of the synthesized charged (0.8–40 nm) and neutral (2–40 nm) Fe nanoparticles at the output of the alumina tube (high-current discharge in He). Temporal behavior of different emission lines from the near cathode zone (Cu wire) for the discharge in He. A dense metallic vapor cloud released from the spot is rapidly cooled by adiabatic expansion to the gas, followed by the supersaturation/nucleation of vapors. Cu+* and Cu* lines reflect the cooling of the dense plasma of Cu vapor.