Related Experiment Videos
Two-dimensional effects in laser-created plasmas measured with soft-x-ray laser interferometry
J Filevich1, J J Rocca, E Jankowska
1Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO 80523, USA.
Summary
Laser interferometry revealed unexpected inverted density profiles in laser-created plasmas. This phenomenon, driven by radiation-induced ablation and cooling, impacts plasma dynamics.
Area of Science:
- Plasma physics
- Laser-plasma interactions
- Hydrodynamic modeling
Background:
- Laser-created plasmas are crucial for inertial confinement fusion research.
- Understanding plasma density profiles is key to controlling energy transport.
Purpose of the Study:
- To investigate the plasma density profile formation under specific laser conditions.
- To elucidate the underlying physical mechanisms driving observed plasma structures.
Main Methods:
- Soft-x-ray laser interferometry was used to diagnose plasma density.
- Numerical simulations were employed to model plasma hydrodynamics.
- Characterization of laser parameters: 1.06 microm wavelength, 13-ns pulse duration, moderate intensities (10^11–10^12 W/cm^2), and narrow focal spot (~30 microm).
Main Results:
- Unexpected inverted density profiles with an on-axis density minimum were observed.
- Distinct plasma sidelobes were identified.
- Simulations confirmed strong two-dimensional hydrodynamic behavior as a universal phenomenon.
Conclusions:
- Plasma radiation-induced mass ablation and cooling are the primary drivers of the observed inverted density profiles.
- These findings highlight the importance of considering radiation effects in laser-plasma interactions.
- The results have implications for optimizing laser-driven fusion experiments and understanding astrophysical plasmas.