[Landau ITP Seminars] Friday 21.01.2022

[Serge Krashakov]

Уважаемые коллеги!

На заседании Ученого совета в пятницу 21 января в 11:30 будет заслушан 
доклад:

Inogamov N.A.
*Equations of state (EoS), two white spots in EoS: examples from laser 
ablation in liquid and from laser driven mechanics of deformable solids*

Example 1. Uncertainties of EoS in the near-critical region. Numerical 
modeling of ablation into a liquid has been performed. Molecular 
dynamics and hydrodynamics codes have been applied. Laser radiation 
passes through a transparent liquid and illuminates a metal target. 
Absorption and reflection of light from the target takes place. The 
range of absorbed energies about 1 J/cm2 of interest for technology is 
considered: below these values few nanoparticles (NPs) are formed per 
laser pulse, above - optical breakdown of the liquid takes place. A 
theory has been developed which, using simulation data and thermodynamic 
information (equations of state of matter), makes it possible to 
estimate the mass and composition of NPs formed by laser impact.
[1] N. A. Inogamov, V. V. Zhakhovsky, V. A. Khokhlov, "Physical 
processes during laser ablation into a liquid", Pisma v ZhETP, 115(1), 
20-27 (2022).

Example 2. Uncertainty of the EoS state associated with elastic-plastic 
phenomena in solids. It is necessary to describe both elastic 
characteristics and supercritical fluid at the same time.
Powerful laser exposure causes irreversible changes in the crystal 
structure of the target. These changes are the basis of laser shock 
peening (LSP) technologies. The processes determining the thickness of 
the residual strain layer and related residual stresses are investigated 
in this work. It is known that the termination of pinning is associated 
with the attenuation of the laser shock wave. In this work, new 
information was obtained concerning the transformation of the wave from 
elastic-plastic to elastic mode of propagation in the case of picosecond 
impact. The elastic wave is useless for pinning. It turns out that 
during the transformation, the classical configuration with the plastic 
jump and the elastic precursor before it disappears. In this case, the 
leading edge of the expanding plastic layer gradually reduces its speed 
below the volume speed of sound, smears inside the rarefaction wave and 
stops. While the elastic system of waves is very important for the 
modern laser opto-acoustics applications.
[2] N. A. Inogamov, E. A. Perov, V. V. Zakhovsky, V. V. Shepelev, Y. V. 
Petrov, S. V. Fortova, "Laser Shock Wave: Plasticity, Residual 
Deformation Layer Thickness and Transition from Elastic-Plastic to 
Elastic Propagation Mode", Pisma v ZhETP, 115(2), 80-88 (2022).


ID и пароль онлайн-трансляции в Zoom те же, что и для предыдущих 
трансляций докладов на Ученом совете:
https://zoom.us/j/96899364518?pwd=MzBsR2lYT0lYL2x2b1oyNU9LeWlWUT09
Meeting ID: 968 9936 4518
Пароль: 250319
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