Energy transport analysis in ultrashort pulse laser ablation through combined molecular dynamics and Monte Carlo simulation

Journal Article · Wed Sep 01 00:00:00 EDT 2010 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.82.094111· OSTI ID:21421437

Wenqian, Hu; Shin, Yung C; King, Galen ^[1]

---

1. School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

Mechanisms of energy transport during ultrashort laser pulses (USLPs) ablation are investigated in this paper. Nonequilibrium electron-transport, material ionization, as well as density change effects, are studied using atomistic models--the molecular dynamics (MD) and Monte Carlo (MC) methods, in addition to the previously studied laser absorption, heat conduction, and stress wave propagation. The target material is treated as consisting of two subsystems: valence-electron system and lattice system. MD method is applied to analyze the motion of atoms while MC method is applied for simulating electron dynamics and multiscattering events between particles. Early-time laser-energy absorption and redistribution as well as later-time material ablation and expansion processes are analyzed. This model is validated in terms of ablation depth, lattice/electron temperature distribution as well as evolution, and plume front velocity, through comparisons with experimental or theoretical results in literature. It is generally believed that the hydrodynamic motion of the ablated material is negligible for USLP but this study shows it is true only for its effect on laser-energy deposition. This study shows that the consideration of hydrodynamic expansion and fast density change in both electron and lattice systems is important for obtaining a reliable energy transport mechanism in the locally heated zone.

• OSTI ID: 21421437
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 82, Issue 9; Other Information: DOI: 10.1103/PhysRevB.82.094111; (c) 2010 The American Physical Society; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABLATION
ABSORPTION HEAT
ATOMS
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
DENSITY
DISTRIBUTION
ELECTRON TEMPERATURE
ELECTRONS
ENERGY ABSORPTION
EXPANSION
IONIZATION
LASER RADIATION
MOLECULAR DYNAMICS METHOD
MONTE CARLO METHOD
PULSES
STRESSES
VELOCITY
WAVE PROPAGATION
ABSORPTION
CALCULATION METHODS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY
ENTHALPY
EVALUATION
FERMIONS
HEAT
LEPTONS
PHYSICAL PROPERTIES
RADIATIONS
SIMULATION
SORPTION
THERMODYNAMIC PROPERTIES