Development of a laser amplification system for the multi-pass Thomson scattering system for GAMMA 10/PDX

Area of Science:

• Plasma Physics
• Optical Diagnostics
• Fusion Energy Research

Background:

• Multi-pass Thomson scattering (MPTS) enhances Thomson scattering (TS) signals for improved diagnostic time resolution.
• Standard MPTS systems suffer signal intensity loss due to optical component damping over multiple passes.
• The GAMMA 10/PDX tokamak utilizes a polarization-based MPTS configuration with an image relaying system.

Purpose of the Study:

• To develop a novel MPTS system capable of overcoming signal degradation in multi-pass configurations.
• To improve measurement accuracy and achieve megahertz sampling time resolution in plasma diagnostics.
• To demonstrate the efficacy of a laser amplification system within an MPTS setup.

Main Methods:

• Implementation of a polarization-based multi-pass Thomson scattering system.
• Integration of an image relaying system for signal transmission.
• Development and incorporation of a laser amplification system to restore laser power after multiple passes.
• Gas scattering experiments to validate the enhanced MPTS system.

Main Results:

• The developed MPTS system successfully compensated for signal intensity decrease across multiple passes.
• The laser amplification system restored degraded laser power to its initial level after six passes.
• Achieved continued multi-pass signals post-laser amplification, a world-first in gas scattering experiments.
• Demonstrated potential for enhanced accuracy and megahertz sampling time resolution.

Conclusions:

• The novel MPTS system with laser amplification effectively mitigates signal loss, significantly enhancing diagnostic capabilities.
• This advancement represents a breakthrough in achieving high-fidelity plasma measurements with improved temporal resolution.
• The successful demonstration paves the way for more accurate and detailed plasma diagnostics in fusion research.