SPARC x-ray diagnostics: Technical and functional overview

Area of Science:

• Nuclear Fusion Science
• Plasma Physics
• X-ray Diagnostics

Background:

• Tokamak fusion devices require sophisticated diagnostics for operational control and physics understanding.
• X-ray measurements are crucial for monitoring plasma behavior, instabilities, and particle content.

Purpose of the Study:

• To detail SPARC's three primary x-ray diagnostics and their roles in tokamak operation.
• To explain the design and function of in-vessel tomography, ex-vessel scintillators, and Bragg spectrometers.
• To highlight how diagnostic design supports safety (tritium containment, neutron shielding) and future sensor development.

Main Methods:

• In-vessel soft x-ray tomography for plasma position, MHD activity, and impurities.
• Ex-vessel hard x-ray scintillators for detecting runaway electrons during plasma startup.
• X-ray Bragg spectrometers for ion temperature, plasma rotation, and impurity emission measurements.

Main Results:

• The soft x-ray tomography provides early operational data.
• Hard x-ray scintillators effectively detect runaway electrons.
• Bragg spectrometers yield crucial data on ion temperature and plasma dynamics.

Conclusions:

• SPARC's x-ray diagnostics are integral to tokamak operation and physics research.
• The diagnostic designs balance data acquisition with critical safety and future innovation requirements.
• These diagnostics enhance fusion power uncertainty reduction and plasma control capabilities.