A5031551065- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Analytical chemistry methods development
- Mass Spectrometry Techniques and Applications
- Spectroscopy and Laser Applications
- Plasma Diagnostics and Applications
- Laser Design and Applications
- Astro and Planetary Science
- Plasma Applications and Diagnostics
- Various Chemistry Research Topics
- Laser-Ablation Synthesis of Nanoparticles
- Quantum optics and atomic interactions
- Mercury impact and mitigation studies
- Catalytic Processes in Materials Science
- Ion-surface interactions and analysis
- Laser Material Processing Techniques
- Spectroscopy Techniques in Biomedical and Chemical Research
- Cold Atom Physics and Bose-Einstein Condensates
- Molecular Spectroscopy and Structure
- Advanced Chemical Physics Studies
- Photoacoustic and Ultrasonic Imaging
- Energetic Materials and Combustion
- Diamond and Carbon-based Materials Research
- Atmospheric Ozone and Climate
- Spectroscopy and Quantum Chemical Studies
University of Tennessee at Knoxville
2013-2024
University of Tennessee Health Science Center
2014-2023
Cairo University
2019
Centre National de la Recherche Scientifique
2018
Laboratoire pour l'utilisation des lasers intenses
2018
Sorbonne Université
2018
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2018
Marie Curie
2018
Moscow Institute of Physics and Technology
2018
Université Paris-Saclay
2018
Temperature and pressure profiles are computed by the use of a two-dimensional, axially symmetric, time-accurate computational fluid-dynamic model for nominal 10-ns optical breakdown laser pulses. The includes kinetics mechanism that implements plasma equilibrium in ionized regions nonequilibrium, multistep, finite-rate reactions nonionized regions. Fluid-physics phenomena following laser-induced recorded with high-speed shadowgraph techniques. predicted fluid shown direct comparison...
Stark-broadened emission profiles of the Balmer series Hbeta lines are measured subsequent to nanosecond laser-induced optical breakdown in gaseous hydrogen. Electron number densities found from time-resolved spectra emissions be range 10(15)-10(18) cm(-3). These results compared with Halpha measurements for which as high 10(19) cm(-3) determined Stark widths and shifts. Good agreement is reported inferred emissions, down an electron density 3 x 10(16) cm(-3), by accurate treatment ion...
The temperature in an aluminized propellant is determined as a function of height and plume depth from diatomic AlO thermal emission spectra. Higher the plume, 305 508 mm burning surface, measured spectra show average with 1σ errors 2980 ± 80 K. Lower 152 2450 100 K inferred. analysis yields higher temperatures when using constant emissivity. Particle size effects along are investigated wavelength-dependent emissivity models.
This work describes the use of a laser-induced breakdown spectroscopy (LIBS) system to conduct macroscopic elemental mapping uranium and iron on exterior surface interior center cross-section surrogate nuclear debris for first time. The results suggest that similar LIBS systems could be packaged as an effective instrument screening samples during collection activities in field or process control measurements production surrogates. technique focuses mitigation chemical physical matrix effects...
This work communicates a review on Balmer series hydrogen beta line measurements and applications for analysis of white dwarf stars. Laser-induced plasma investigations explore electron density temperature ranges comparable to star signatures such as Sirius B, the companion brightest observable from earth. Spectral shape characteristics include width, peak separation, central dip-shift, thereby providing three indicators measurements. The alpha shows two primary line-profile parameters...
Spectral measurements of the H(α) Balmer series line and continuum radiation are applied to draw inferences electron density, temperature, level self-absorption in laser ablation a solid ice target ambient air. Electron densities 17 3.2×10(24) m(-3) determined from absolute calibrated emission coefficients for time delays 100-650 ns after generation plasma using Q-switched Nd:YAG radiation. The corresponding temperatures 4.5-0.95 eV were evaluated spectral radiance at longer wavelengths....
A hand-held device for laser-induced breakdown spectroscopy has been investigated the determination of uranyl fluoride surface contamination. This research demonstrates ability to successfully detect uranium on surfaces when using a low resolving power (λ/Δλ=4000) spectrograph, with 5 mJ energy per 1 ns pulsed laser radiation, available as commercially packaged system. Sand/uranyl mixtures are prepared simulate residue likely encountered during decontamination efforts at facilities that...
This article reports new measurements of laser-induced plasma hypersonic expansion diatomic molecular cyanide (CN). Focused, high-peak-power 1064 nm Q-switched radiation the order 1 TW/cm 2 generated optical breakdown in a cell containing 1:1 molar gas mixture N and CO at fixed pressure 1.1 × 10 5 Pascal 100 mL/min flow mixture. Line-of-sight (LOS) analysis recorded spectra indicated outgoing shockwave speeds well excess Mach 5. Spectra atomic carbon confirmed increased electron density near...
The fluid flow phenomena resulting from laser-spark decay is described based on a numerical simulation. transient model involves the solution of two-dimensional axial-symmetric transport equations mass, momentum, and energy in nitrogen gas. Initial temperature pressure profiles are taken upon termination laser pulse, laserinduced plasma formation processes. specific heat property models include effects dissociation ionization. Temperature, pressure, velocity reported at selected times,...
We report time-resolved measurements of diatomic aluminum monoxide spectra in the study laser ablation by use frequency-quadrupled 266 nm Nd:YAG radiation. Spectroscopic temperatures 3432(35) K and 3329(13) are obtained at a delay time 20mu, respectively, modified Boltzmann plot Nelder-Mead algorithm fitting recorded spectrum.
We present results including measurement and analysis of titanium monoxide. Pulsed, nanosecond Nd:YAG laser radiation is used in a typical laser-induced breakdown spectroscopy arrangement to record the spectra. This scheme provides experiments analogous pulsed deposition tactics allows for time-resolved spectroscopic analysis. The computed spectra are generated from new, accurate line-strength file that us accurately predict γ (A3Φ→X3Δ) γ' (B3Π→X3Δ) spectral signatures. infer temperature on...
Effects of spherical aberrations in converging and diverging lens-axicon doublets are investigated. Intensity profiles obtained the line ring focal regions by numerically solving Fresnel-Kirchhoff integral. Comparisons with aberration-free computations show that higher peak irradiances occur for doublet when included. Results presented axicons small apex angles combinations illuminated collimated Gaussian 1.064-mum laser beams.
Spectra from plasma produced by laser-induced breakdown of graphite were recorded and analyzed to increase our understanding the way in which carbon nanoparticles are created during Nd:YAG laser ablation graphite. The effects various buffer gases studied. Electron density temperature determined spectra first second ions atomic carbon. C2 Swan spectrum was also prominent most measured spectra. Temperature inferred each experimental determination for a synthetic best fitted, least-squares...