Plume dynamics in femtosecond laser ablation of metals

Journal Article · Fri Oct 08 00:00:00 EDT 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3507157· OSTI ID:21454847

Donnelly, T; Lunney, J G ^[1]; Amoruso, S; Bruzzese, R; Wang, X ^[2]

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1. School of Physics, Trinity College Dublin, Dublin 2 (Ireland)
2. Coherentia CNR-INFM and Dipartimento di Scienze Fisiche, Universita degli Studi di Napoli Fedrico II, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126, Napoli (Italy)

In femtosecond laser ablation the plume has two components: a faster-moving plasma part and a slower nanoparticle plume which contains most of the ablated material. This paper describes the results of experiments to comprehensively characterize the plume in laser ablation of Ni with {approx_equal}300 fs pulses at 527 nm. Both single-pulse and double-pulse irradiation was used. The laser ablation depth was measured using white light interferometry. The dynamics of the plasma part of the ablation plume was measured using Langmuir ion probes. The shape of the overall ablation plume was recorded by depositing a thin film on a transparent substrate and measuring the thickness distribution. The expansion of the plasma plume is well described by the Anismov isentropic model of plume expansion. Just above the ablation threshold, the nanoparticle plume is also well described by the Anisimov expansion model. However, at higher fluence a wider plume is formed, perhaps due to the pressure exerted by plasma. For double-pulse ablation it is observed that as the second pulse is delayed beyond {approx_equal}20 ps the ablation depth is reduced and the ion yield is increased. This behaviour is due to reheating of the nascent plasma plume produced by the first pulse. This generates a pressure pulse that acts as a tamper which impedes the fragmentation and ablation of deeper layers of material.

• OSTI ID: 21454847
• Journal Information: AIP Conference Proceedings, Vol. 1278, Issue 1; Conference: International symposium on high power laser ablation 2010, Santa Fe, NM (United States), 18-22 Apr 2010; Other Information: DOI: 10.1063/1.3507157; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ABLATION
INTERFEROMETRY
ION PROBES
ISENTROPIC PROCESSES
LASER-PRODUCED PLASMA
LASERS
LAYERS
NANOSTRUCTURES
NICKEL
PLASMA DIAGNOSTICS
PLUMES
PULSED IRRADIATION
SUBSTRATES
THIN FILMS
ELEMENTS
FILMS
IRRADIATION
METALS
PLASMA
PROBES
TRANSITION ELEMENTS