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Title: Experimental and theoretical studies of particle generation afterlaser ablation of copper with background gas at atmosphericpressure

Abstract

Laser ablation has proven to be an effective method for generating nanoparticles; particles are produced in the laser induced vapor plume during the cooling stage. To understand the in-situ condensation process, a series of time resolved light scattering images were recorded and analyzed. Significant changes in the condensation rate and the shape of the condensed aerosol plume were observed in two background gases, helium and argon. The primary particle shape and size distribution were measured using a transmission electron microscope (TEM), a scanning electron microscope (SEM) and a differential mobility analyzer (DMA). The gas dynamics simulation included nucleation and coagulation within the vapor plume, heat and mass transfer from the vapor plume to the background gas, and heat transfer to the sample. The experimental data and the calculated evolution of the shape of the vapor plume showed the same trend for the spatial distribution of the condensed particles in both background gases. The simulated particle size distribution also qualitatively agreed with the experimental data. It was determined that the laser energy, the physical properties of the background gas (conductivity, diffusivity and viscosity), and the shape of the ablation system (ablation chamber and the layout of the sample) have strong effectsmore » on the condensation process and the subsequent sizes, shapes and degree of aggregation of the particles.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE. Administrator for National Nuclear Security AdminNonproliferation and NationalSecurity Program Direction
OSTI Identifier:
929332
Report Number(s):
LBNL-63255
Journal ID: ISSN 0021-8979; JAPIAU; R&D Project: 675201; BnR: NN2001000; TRN: US200813%%195
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 101; Journal Issue: 12; Related Information: Journal Publication Date: 06/2007
Country of Publication:
United States
Language:
English
Subject:
37; ABLATION; AEROSOLS; ARGON; ATMOSPHERIC PRESSURE; COPPER; ELECTRON MICROSCOPES; GASES; HEAT TRANSFER; HELIUM; LASERS; LIGHT SCATTERING; MASS TRANSFER; NUCLEATION; PARTICLE SIZE; PHYSICAL PROPERTIES; PLUMES; SPATIAL DISTRIBUTION; VISCOSITY

Citation Formats

Wen, Sy-Bor, Mao, Xianglei, Greif, Ralph, and Russo, Richard E. Experimental and theoretical studies of particle generation afterlaser ablation of copper with background gas at atmosphericpressure. United States: N. p., 2007. Web. doi:10.1063/1.2748635.
Wen, Sy-Bor, Mao, Xianglei, Greif, Ralph, & Russo, Richard E. Experimental and theoretical studies of particle generation afterlaser ablation of copper with background gas at atmosphericpressure. United States. doi:10.1063/1.2748635.
Wen, Sy-Bor, Mao, Xianglei, Greif, Ralph, and Russo, Richard E. Thu . "Experimental and theoretical studies of particle generation afterlaser ablation of copper with background gas at atmosphericpressure". United States. doi:10.1063/1.2748635. https://www.osti.gov/servlets/purl/929332.
@article{osti_929332,
title = {Experimental and theoretical studies of particle generation afterlaser ablation of copper with background gas at atmosphericpressure},
author = {Wen, Sy-Bor and Mao, Xianglei and Greif, Ralph and Russo, Richard E.},
abstractNote = {Laser ablation has proven to be an effective method for generating nanoparticles; particles are produced in the laser induced vapor plume during the cooling stage. To understand the in-situ condensation process, a series of time resolved light scattering images were recorded and analyzed. Significant changes in the condensation rate and the shape of the condensed aerosol plume were observed in two background gases, helium and argon. The primary particle shape and size distribution were measured using a transmission electron microscope (TEM), a scanning electron microscope (SEM) and a differential mobility analyzer (DMA). The gas dynamics simulation included nucleation and coagulation within the vapor plume, heat and mass transfer from the vapor plume to the background gas, and heat transfer to the sample. The experimental data and the calculated evolution of the shape of the vapor plume showed the same trend for the spatial distribution of the condensed particles in both background gases. The simulated particle size distribution also qualitatively agreed with the experimental data. It was determined that the laser energy, the physical properties of the background gas (conductivity, diffusivity and viscosity), and the shape of the ablation system (ablation chamber and the layout of the sample) have strong effects on the condensation process and the subsequent sizes, shapes and degree of aggregation of the particles.},
doi = {10.1063/1.2748635},
journal = {Journal of Applied Physics},
number = 12,
volume = 101,
place = {United States},
year = {Thu May 31 00:00:00 EDT 2007},
month = {Thu May 31 00:00:00 EDT 2007}
}
  • The metal carbide radicals AlC and AlC{sub 2} have been generated by the laser vaporization of aluminum carbide and trapped in neon and argon matrices at 4 K for electron spin resonance (ESR) characterization. These results provide the first experimental evidence showing that AlC has a {sup 4}{Sigma} ground electronic state and that AlC{sub 2} is {ital X} {sup 2}{ital A}{sub 1}. {ital Ab} {ital initio} theoretical calculations were conducted for the geometries and various nuclear hyperfine parameters in both radicals which yielded {ital A} values in reasonable agreement with the observed. In AlC, the three unpaired electrons reside primarilymore » on carbon with the following neon matrix magnetic parameters (MHz): {ital g}{sub {parallel}}=2.000(1); {ital g}{sub {perpendicular}}=2.0010(5); {vert bar}{ital A}{sub {perpendicular}}(Al){vert bar}=33.2(5); {vert bar}{ital A}{sub {parallel}}(Al){vert bar}=3(3); {ital A}{sub {perpendicular}}({sup 13}C)=52.1(5); {ital A}{sub {parallel}}({sup 13}C)=52(2); and {ital D}(zero field splitting)=374(1). For AlC{sub 2}, the spin density resides predominantly in an aluminum 3{ital p}{sub {ital z}}/3{ital s} hybrid directed away from C{sub 2}. The neon magnetic parameters (MHz) are: {ital g}{sub {parallel}}=2.0005(5); {ital g}{sub {perpendicular}}=1.9965(3); {ital A}{sub {perpendicular}}(Al)=941.5(5); {ital A}{sub {parallel}}(Al)=1067(1); {vert bar}{ital A}{sub {parallel}}({sup 13}C){vert bar}=59(1); and {vert bar}{ital A}{sub {perpendicular}}({sup 13}C){vert bar}=52(1).« less
  • Sections of the potential energy surface of [Fe,C,H{sub 4},O]{sup +} ions are probed experimentally by using collisional activation mass spectrometry as well as theoretically by ab initio MO studies. Evidence is presented for the existence of several. clearly distinguishable isomers, some of which are relevance in the context of methane activation by FeO{sup +} in the gas phase. 43 refs., 4 fig., 5 tab.
  • Significant laser energy was transferred from the near field scanning optical microscope tip to a silicon wafer producing nanopatterns on the sample surface. The patterns changed from nanoprotrusions to nanocraters when the background gas was changed from air to argon. Two physical mechanisms were attributed to this dramatic change, namely, oxidation and laser ablation. When air was present, oxidation dominated over ablation in the formation of the nanoprotrusions obtained after multiple laser pulses. When oxygen was absent, e.g., pure argon was the background gas, laser ablation was dominant, and nanocraters resulted after multiple laser pulses.
  • Laser ablation of copper with a 4 ns laser pulse at 1064 nm was studied with a series of synchronized shadowgraph (100 fs laser pulses at 400 nm) and emission images (spectral line at 515 nm). Data were obtained at two laser pulse energies (10 and 30 mJ) and in three background gases (He, Ne, and Ar) at atmospheric pressure. The laser energy conversion ratio and the amount of sample vaporized for ablation in each condition were obtained by the theoretical analysis reported in paper I from trajectories of the external shock wave, internal shock wave, and contact surface betweenmore » the Cu vapor and the background gas. All three quantities were measured from shadowgraph and emission images. The results showed that E, the amount of energy that is absorbed by the copper vapor, decreases as the atomic mass of the background gas increases; and M, the mass of the sample converted into vapor, is almost independent of the background gas [Horn et al., Appl. Surf. Sci. 182, 91 (2001)]. A physical interpretation is given based on the phenomena observed in shadowgraph and emission images during the first tens of nanoseconds after the beginning of the laser pulse for ablation in different background gases. In addition, an internal shock wave was observed in the emission images during the first tens of nanoseconds after the laser pulse, which strikes the surface and should be one of the mechanisms inducing the liquid sample ejection. Also, a significant vortex ring near the target was observed in emission images at longer times after the laser pulse (>100 ns) which distorts the otherwise hemispherical expansion of the vapor plume.« less
  • Beam-gas collision created experimental background, i.e., singles, has affected heavy ion and polarized proton operations in Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The gas molecules in interaction region are mainly caused by the electron induced gas desorption, and the electrons are produced from the beam induced electron multipacting, or called electron cloud. The background has a dependence on the usual electron cloud related parameters, such as the bunch intensity, bunch spacing, and the solenoid field. With the RHIC upgrade plan, the experimental background may become a luminosity limiting factor. Mitigations are discussed.