Design of JT-60SA core Thomson scattering diagnostic system

Area of Science:

• Fusion Energy Research
• Plasma Physics
• Diagnostic Instrumentation

Background:

• JT-60SA tokamak requires advanced diagnostics for plasma characterization.
• Superconducting fusion devices present unique challenges for diagnostic systems.

Purpose of the Study:

• To design and present an incoherent Thomson scattering diagnostic for JT-60SA.
• To achieve high-resolution electron temperature and density profile measurements.
• To address challenges posed by superconducting fusion environments.

Main Methods:

• Detailed design of collection optics, fiber optics with alignment, and polychromators.
• Development of optics resistant to high temperatures and radiation.
• Incorporation of replaceable lens materials for future radiation hardening.

Main Results:

• Achieves target radial spatial resolution of 25 mm with 46 spatial channels.
• Provides few percent accuracy for electron temperature and density at core plasma densities (7.5 × 10^19 m^-3).
• Collection optics designed to overcome space, temperature, and radiation constraints.

Conclusions:

• The designed Thomson scattering diagnostic is suitable for JT-60SA's operational requirements.
• The system ensures stable measurement accuracy and can be upgraded for future high-radiation conditions.
• This diagnostic will enhance understanding of plasma core properties in fusion devices.