Implementation of a Wollaston interferometry diagnostic on OMEGA EP

Area of Science:

• Plasma Physics
• Laser-Induced Plasmas
• Optical Diagnostics

Background:

• Experiments on the OMEGA EP laser system generate plasma plumes.
• Measuring electron density in these plasmas is crucial for understanding experimental outcomes.
• Existing diagnostics may have limitations in resolution or flexibility.

Purpose of the Study:

• To present a new Wollaston interferometer design for measuring plasma plume electron density.
• To demonstrate the diagnostic's unique configuration and capabilities.
• To characterize plasma density within a specific range.

Main Methods:

• Utilizing a Wollaston prism to split a 263 nm laser probe beam into two.
• Integrating the interferometer into the 4ω probe system with an f/4 imaging system.
• Implementing a unique configuration allowing independent adjustment of fringe spacing (17-76 μm/fringe).

Main Results:

• The diagnostic achieves a field of view of approximately 1.2 × 1.6 mm at target chamber center.
• High imaging resolution of 5 μm is maintained.
• Accurate plasma density characterization achieved for densities ranging from 3 × 10^18 to 1 × 10^20 cm^-3.

Conclusions:

• The developed Wollaston interferometer is a valuable tool for plasma diagnostics.
• The independent control over fringe spacing offers enhanced flexibility.
• This diagnostic enables precise electron density measurements in laser-produced plasmas.