Simulation of femtosecond laser ablation of gold into water Povarnitsyn M.E. 1, Itina T.E. 2,...

Simulation of femtosecondlaser ablation of gold into water

Povarnitsyn M.E.1, Itina T.E.2, Levashov P.R.1, Khishchenko K.V.1

1JIHT RAS, Moscow, Russia2LabHC, St-Etienne, France

povar@ihed.ras.ru

XXVIII International Conference on Interaction of Intense Energy Fluxes with MatterMarch 2-7, 2013, Elbrus, Kabardino-Balkaria, Russia

Motivation

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

Application of NPs – cancer and antibacterial treatment,imaging, censors, etc.

H20

Au

laser

Size distribution of NPs

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

Problem definition

H20

Au

laser

H2O Au

z

= 800 nm, = 200 fsI 1013 W/cm2

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

Two-temperature hydrodynamic model

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

Eidmann et al. PRE 62 (2000)

Pump-probe for cold

Elsayed et al. PRL 58, 1212 (1987) CuGroeneveld et al. PRL 64, 784 (1990) AgSchoenlein et al. PRL 58, 1680 (1987) Au

Collision frequency

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

Thermal conductivity and electron-ion coupling

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

Laser energy absorption

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

Phase diagram of Au (EOS)

a – 0 GPab – -1 GPac – -4 GPad – -7 GPa

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

GES library version 1.0.7: #23004 (two-temperature, multi-phase)

Water Hugoniot curve (EOS)

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

GES library version 1.0.7 #02250 (single-phase, caloric)

• Two-temperature one-fluid hydrodynamics

• Laser absorption (Helmholtz equation for S or P polarization)

• Electron thermal conductivity

• Electron-ion collisions and energy exchange

• Two-temperature equation of state

• Several materials

Model summary

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

Main stages of fs ablation

H20

Au

laser

H2O Au

z

= 800 nm, = 200 fs

Au

Au

H2O

H2O SW SW

AuH2O

1)

2)

3)

4)

Te >> Ti

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

I0=2×1013 W/cm2 (Fabs= 0.098 J/cm2)

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

I0=3×1013 W/cm2 (Fabs= 0.26 J/cm2)

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

r 10 – 100 nm

I0=4×1013 W/cm2 (Fabs= 0.55 J/cm2)

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

I0=5×1013 W/cm2 (Fabs= 0.95 J/cm2)

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

I0=5×1013 W/cm2 (Fabs= 0.95 J/cm2)

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

• The large-size particles are the result of liquid layer ejection and fragmentation

• The near-critical and supercritical trajectories appear for front target layers and the mass fraction of the liquid–gas mixture increases

• Formation of small NPs can be observed for these trajectories and estimation of the NP size matches quite well with the experimental findings

• The calculation results explain bimodal size distributions of NPs frequently observed in experiment

Summary

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013

[1] M.E. Povarnitsyn, N.E. Andreev, E.M. Apfelbaum, T.E. Itina, K.V. Khishchenko, O.F. Kostenko, P.R. Levashov and M.E. Veysman. A wide-range model for simulation of pump-probe experiments with metals. // Applied Surface Science. 258, 9480 (2012).

[2] M. E. Povarnitsyn, N. E. Andreev, P. R. Levashov, K. V. Khishchenko, and O. N. Rosmej. Dynamics of thin metal foils irradiated by moderate-contrast high-intensity laser beams // Phys. Plasmas. 19, 023110 (2012).

[3] M. E. Povarnitsyn, T. E. Itina, P. R. Levashov, K. V. Khishchenko. Mechanisms of nanoparticle formation by ultra-short laser ablation of metals in liquid environment // Phys. Chem. Chem. Phys. 15, 3108 (2013).

Publications

Povarnitsyn et al. Simulation of femtosecond… March 2, 2013