In-vessel design of a two-color heterodyne laser interferometer system for SPARC

Area of Science:

• Fusion energy research
• Plasma diagnostics
• Optical engineering

Background:

• The SPARC tokamak requires advanced diagnostics for plasma control.
• Interferometry is crucial for measuring plasma density.
• In-vessel systems face extreme operational conditions.

Purpose of the Study:

• To present the in-vessel design of the SPARC interferometry diagnostic system.
• To ensure system functionality and durability for "day-1" plasma operations.
• To optimize the design for plasma-facing optical components.

Main Methods:

• Utilizing infrared lasers for higher optical throughput.
• Optimizing in-vessel geometry to protect optical components.
• Designing custom all-metal parts for harsh environments.
• Employing modeling and simulation tools for design validation.

Main Results:

• The design prioritizes protection of plasma-facing optical components.
• Custom-designed all-metal assemblies ensure functionality under harsh conditions.
• The system is engineered to withstand electromagnetic disruptions and thermal events.
• Transient heat loading effects on mirrors are integrated into the design.

Conclusions:

• The SPARC interferometry diagnostic system is designed for robust performance and longevity.
• The design mitigates risks associated with plasma-facing components.
• Advanced modeling and design ensure system reliability for plasma density feedback control.