Spatially translatable optical fiber-coupled heterodyne interferometer.

Area of Science:

• Plasma physics
• Interferometry
• Diagnostic tools

Background:

• Interferometers are valuable for measuring line-averaged electron density.
• Traditional interferometers are limited to fixed measurement locations.
• Understanding plasma jet dynamics requires spatially resolved measurements.

Purpose of the Study:

• To develop a spatially translatable interferometer for plasma diagnostics.
• To measure the electron density of a high-speed MHD-driven plasma jet interacting with a target cloud.
• To deduce changes in jet velocity based on electron density profiles.

Main Methods:

• Utilized a fiber-coupled interferometer system.
• Employed a Helium-Neon (He-Ne) laser coupled to a polarization-maintaining single-mode optical fiber.
• Integrated a vacuum feedthrough for robust operation.
• Achieved spatial translation of the interferometer setup.

Main Results:

• Successfully measured the spatial-temporal profile of line-averaged electron density.
• Observed the interaction of an MHD-driven plasma jet with a target cloud.
• Obtained data indicative of changes in jet velocity post-collision.

Conclusions:

• The spatially translatable interferometer enables dynamic measurements of plasma jet characteristics.
• This technique provides insights into the effects of collisions on plasma jet velocity.
• The developed system enhances the diagnostic capabilities for high-speed plasma phenomena.