Atomistic simulation study of short pulse laser interactions with a metal target under conditions of spatial confinement by a transparent overlayer
- Electro Scientific Industries, Inc., 13900 NW Science Park Drive, Portland, Oregon 97229 (United States)
The distinct characteristics of short pulse laser interactions with a metal target under conditions of spatial confinement by a solid transparent overlayer are investigated in a series of atomistic simulations. The simulations are performed with a computational model combining classical molecular dynamics (MD) technique with a continuum description of the laser excitation, electron-phonon equilibration, and electronic heat transfer based on two-temperature model (TTM). Two methods for incorporation of the description of a transparent overlayer into the TTM-MD model are designed and parameterized for Ag-silica system. The material response to the laser energy deposition is studied for a range of laser fluences that, in the absence of the transparent overlayer, covers the regimes of melting and resolidification, photomechanical spallation, and phase explosion of the overheated surface region. In contrast to the irradiation in vacuum, the spatial confinement by the overlayer facilitates generation of sustained high-temperature and high-pressure conditions near the metal-overlayer interface, suppresses the generation of unloading tensile wave, decreases the maximum depth of melting, and prevents the spallation and explosive disintegration of the surface region of the metal target. At high laser fluences, when the laser excitation brings the surface region of the metal target to supercritical conditions, the confinement prevents the expansion and phase decomposition characteristic for the vacuum conditions leading to a gradual cooling of the hot compressed supercritical fluid down to the liquid phase and eventual solidification. The target modification in this case is limited to the generation of crystal defects and the detachment of the metal target from the overlayer.
- OSTI ID:
- 22275576
- Journal Information:
- Journal of Applied Physics, Vol. 115, Issue 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Two mechanisms of nanoparticle generation in picosecond laser ablation in liquids: the origin of the bimodal size distribution
|
journal | January 2018 |
Femtosecond laser generation of microbumps and nanojets on single and bilayer Cu/Ag thin films
|
journal | January 2019 |
Electron-phonon thermalization in a scalable method for real-time quantum dynamics
|
journal | January 2016 |
Similar Records
Molecular dynamics study of femtosecond laser interactions with Cr targets
Generation of nanocrystalline surface layer in short pulse laser processing of metal targets under conditions of spatial confinement by solid or liquid overlayer