Simulation of femtosecond laser ablation of gold into water

1
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,
Russia 2LabHC, St-Etienne, France povar_at_ihed.ras.
ru
XXVIII International Conference on Interaction of
Intense Energy Fluxes with MatterMarch 2-7,
2013, Elbrus, Kabardino-Balkaria, Russia
2
Motivation
Application of NPs cancer and antibacterial
treatment, imaging, censors, etc.
3
Size distribution of NPs
4
Problem definition
H2O
Au
? 800 nm, ? 200 fs I ? 1013 W/cm2
z
5
Two-temperature hydrodynamic model
6
Collision frequency
Eidmann et al. PRE 62 (2000)
Pump-probe for ?cold Elsayed et al. PRL 58, 1212
(1987) Cu Groeneveld et al. PRL 64, 784
(1990) Ag Schoenlein et al. PRL 58, 1680 (1987) Au
7
Thermal conductivity and electron-ion coupling
8
Laser energy absorption
9
Phase diagram of Au (EOS)
GES library version 1.0.7 23004
(two-temperature, multi-phase)
a 0 GPa b -1 GPa c -4 GPa d -7 GPa
10
Water Hugoniot curve (EOS)
GES library version 1.0.7 02250 (single-phase,
caloric)
11
Model summary

• 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

12
Main stages of fs ablation
H2O
Au
1) 2) 3) 4)
? 800 nm, ? 200 fs
Au
H2O
Te gtgt Ti
SW
Au
H2O
SW
Au
H2O
z
13
I021013 W/cm2 (Fabs 0.098 J/cm2)
14
I031013 W/cm2 (Fabs 0.26 J/cm2)
r ? 10 100 nm
15
I041013 W/cm2 (Fabs 0.55 J/cm2)
16
I051013 W/cm2 (Fabs 0.95 J/cm2)
17
I051013 W/cm2 (Fabs 0.95 J/cm2)
?
18
Summary

• 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 liquidgas 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

19
Publications
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).
20
Concept of Virtual Laser Laboratory
http//vll.ihed.ras.ru