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Full-Text Articles in Physics

Comparison Of Plume Dynamics For Laser Ablated Metals: Al And Ti, William A. Bauer, Glen P. Perram, Timothy Haugan Mar 2018

Comparison Of Plume Dynamics For Laser Ablated Metals: Al And Ti, William A. Bauer, Glen P. Perram, Timothy Haugan

Faculty Publications

Emissive plumes from pulsed laser ablation of bulk Ti and Al from KrF laser irradiation at laser fluence up to 3.5 J/cm2 and argon background pressures of 0–1 Torr have been observed using gated intensified charged-coupled device imagery. Mass loss for Ti increases from 0.1 to 0.8 μg/pulse as pulse energy increase from 174 to 282 mJ/pulse (35–170 photons/atom) and decreases by ∼30% as pressure increases from vacuum to 1 Torr. Early plume energies are described by the free expansion velocities of 1.57 ± 0.02 and of 1.81 ± 0.07 cm/μs for Ti and Al, respectively, …


Transient Lattice Deformations Of Crystals Studied By Means Of Ultrafast Time-Resolved X-Ray And Electron Diffraction, Runze Li, Kyle Sundqvist, Jie Chen, H. E. Elsayed-Ali, Jie Zhang, Peter M. Rentzepis Jan 2018

Transient Lattice Deformations Of Crystals Studied By Means Of Ultrafast Time-Resolved X-Ray And Electron Diffraction, Runze Li, Kyle Sundqvist, Jie Chen, H. E. Elsayed-Ali, Jie Zhang, Peter M. Rentzepis

Electrical & Computer Engineering Faculty Publications

Ultrafast lattice deformation of tens to hundreds of nanometer thick metallic crystals, after femtosecond laser excitation, was measured directly using 8.04 keV subpicosecond x-ray and 59 keV femtosecond electron pulses. Coherent phonons were generated in both single crystal and polycrystalline films. Lattice compression was observed within the first few picoseconds after laser irradiation in single crystal aluminum, which was attributed to the generation of a blast force and the propagation of elastic waves. The different time scales of lattice heating for tens and hundreds nanometer thick films are clearly distinguished by electron and x-ray pulse diffraction. The electron and lattice …