Tracking ultrafast dynamics of intense shock generation and breakout at target rear

• Published in: Physics of plasmas 2018-11, Vol.25 (11)
• Main Authors: Shaikh, Moniruzzaman, Jana, Kamalesh, Lad, Amit D., Dey, Indranuj, Roy, Sudipta L., Sarkar, Deep, Ved, Yash M., Robinson, Alex P. L., Pasley, John, Ravindra Kumar, G.
• Format: Article
• Language: English
• Subjects: Aluminum; Computer simulation; Femtosecond pulses; Foils; Laser beam heating; Particle in cell technique; Plasma dynamics; Plasma physics; Reflectometry; Shock wave propagation; Shock waves
• ISSN: 1070-664X; 1089-7674
• DOI: 10.1063/1.5049815

We report upon the picosecond plasma dynamics at the rear surface of a thin aluminium foil (of either 5.5 μm or 12 μm thickness) excited by high contrast (picosecond intensity contrast of 10−10), 800 nm, femtosecond pulses at an intensity of 3 × 1019 W/cm2. We employ ultrafast pump-probe reflectometry using a second harmonic probe (400 nm) interacting with the rear surface of the target. A rise in the probe reflectivity 30 ps after the pump pulse interaction reveals the breakout of a shock wave at the target rear surface which reflects the 400 nm probe pulse. Simulations using the ZEPHYROS hybrid particle-in-cell code were performed to understand the heating of the target under the influence of the high intensity laser pulse, and the temperature profile was then passed to the radiation-hydrodynamic simulation code HYADES in order to model the shock wave propagation in the target. A good agreement was found between the calculations and experimental results.