Student: Devi Pooja
Školitel: Ing. Libor Juha, CSc. (FzÚ AV ČR)
Konzultant: Sushil Kumar Singh, Ph.D. (FzÚ AV ČR), Doc. RNDr. Jan Wild, CSc.
Stav práce: zadaná
Anotace:
The thesis will be focused on a detailed study of various mechanism of laser absorption (collisional, resonance, ponderomotive acceleration etc.) and subsequent plasma processes when the high energy beam interacts with the various materials in different aggregate states such as solid, gas and foam targets. The underline physics and investigations relevant with inner plasma processes such as laser absorption, reflection, scattering, generation of energetic particles, radiation and electromagnetic fields are the one of the most fundamental aspects of laser matter interaction which still need to be investigated in detail both experimentally and theoretically. The main goal of this project is to investigate various mechanism of laser absorption and determine the energy balance by measuring energy distribution of particles (electrons, ions) and bremsstrahlung radiation as well as scattered energy of the laser beam from the plasma [1]. Moreover, monitoring the spectrum and intensity of scattered light provides important information about the focused intensity and pre-plasma formation which is also relevant with the study of parametric instabilities in the plasma such as stimulated Raman scattering and two plasma decay. The targets with reduced density as promising material have been proposed to mitigate laser-imprint effects in inertial confinement fusion studies [2] as well as for the generation of bright X-rays for the radiography of dense plasma. The laser pulse penetrates and heats the low-density foam or gas-puff target to a much greater volume converting the material into a quasi-homogeneous plasma with a relatively low and uniform density and a high temperature with respect to massive solid targets. The laser absorption is increased and ion kinetic energy is reduced making the foam efficient sources for x-ray and neutron generation [3]. Moreover, the effect of external magnetic field (few tens of Tesla) on the laser-plasma interaction including parametric instabilities, beam self-focusing and filamentation will also be studied and characterized [4]. These investigations are very crucial not only in the field of inertial fusion research but also has various applications such as the development of bright x-ray sources for radiography, laboratory astrophysics and astrobiology nanolithography, materials processing testing and national security [5-6].
References:
1. S. Singh et al.: Plasma Physics and Controlled Fusion 63, 035004 (2021).
2. N. Woolsey.: Nature 601, 514–515 (2022).
3. M. M. Günther et al.: Nature Communications 13, 170 (2022).
4. Y. Wang et al.: Review of Scientific Instruments 90, 075108 (2019).
5. S. Singh et al.: Plasma Physics and Controlled Fusion 64, 105012 (2022).
6. S. Singh et al.: Review of Scientific Instruments 89, 085118 (2018).