15–21 Sept 2019
Hotel Hermitage, La Biodola Bay, Isola d'Elba, Italy
Europe/Rome timezone

Optical probing of pre-plasma dynamics for laser ion acceleration

18 Sept 2019, 16:00
20m
SBIO (Hotel Biodola)

SBIO

Hotel Biodola

talk WG2-WG5 Joint Session WG2 - WG5 (Joint Session)

Speaker

Max Mäusezahl (Friedrich-Schiller-University Jena, Institute for Optics and Quantum Electronics)

Description

Pre-plasma dynamics on the front side of a target foil in a laser-ion-acceleration process like Target-Normal-Sheath-Acceleration (TNSA) substantially influences the dynamics of the actual Debye-sheath formation and therefore eventually ion yield or ion energies. Acceleration dynamics on sub-picosecond timescales in the laser field are extremely challenging to probe experimentally. Therefore, Particle-In-Cell (PIC) simulations are used to investigate underlying processes, with accurate pre-plasma conditions being a necessary input for a realistic simulation. We realized an optical pre-plasma probing setup based on the well-known interferometric phase-measurement method to extensively study pre-plasma conditions and compare these results to the 1D hydrodynamics code MULTI-fs. Our setup produces laser-induced plasma from a $4\cdot 10^{15}\,\mathrm{Wcm}^{-2}$ pump-laser with properties otherwise similar to the petawatt-class POLARIS laser main beam and can be operated with pulse repetition rates of $1\,\mathrm{Hz}$. The probe pulse of $130\,\mathrm{fs}$ duration can probe the plasma conditions starting at $20\,\mathrm{ps}$ up to $2\,\mathrm{ns}$ after the interaction. In a first experiment, we varied key parameters including angle of incidence, pump polarization and pump intensity. Our results show a wide range of influences to plasma formation and shape and allow the investigation of a simple model bringing MULTI-fs simulation and experiment to very good agreement.

Primary author

Max Mäusezahl (Friedrich-Schiller-University Jena, Institute for Optics and Quantum Electronics)

Co-authors

Dr Sebastian Keppler (Helmholtz-Institute Jena) Mr Issa Tamer (Helmholtz-Institute Jena) Dr Marco Hornung (Helmholtz-Institute Jena) Mr Georg Alexander Becker (Friedrich-Schiller-University Jena, Institute for Optics and Quantum Electronics) Prof. Malte Kaluza (Friedrich-Schiller-University Jena, Helmholtz-Institute Jena)

Presentation materials