New Diagnostic System Proposed for SPARC Tokamak

The SPARC tokamak is a compact high-field device designed to operate at high plasma density with the goal of demonstrating net fusion energy. A recent paper titled "Conceptual Study of a Collective Thomson Scattering Diagnostic for SPARC" by Mads Mentz-Jørgensen and colleagues explores diagnostic options necessary for monitoring and controlling the plasma conditions that have not yet been experimentally explored in SPARC.

The authors propose a collective Thomson scattering (CTS) diagnostic system operating at 140 GHz, which they identify as the most effective option for optimizing the signal-to-noise ratio while minimizing sensitivity to refraction. This system is expected to provide core-localized measurements of several critical parameters, including:

• Fusion-born alpha distribution function
• Main-ion temperature and toroidal rotation
• Fuel-ion ratio
• 3He content

The proposed diagnostic layout is designed to be integrated into SPARC, potentially adding significant value to its diagnostic capabilities without incurring high development costs or extended timelines. The findings suggest that this diagnostic could enhance the understanding of plasma behavior in SPARC, contributing to the broader goal of achieving practical fusion energy.

The full paper can be accessed at arXiv:2408.13669.