Triton burnup measurements in KSTAR using a neutron activation system

Area of Science:

• Nuclear Fusion Engineering
• Plasma Physics
• Particle Transport

Background:

• Triton burnup is a critical metric in magnetic confinement fusion, influencing reactor efficiency and neutronics.
• Accurate measurement of triton burnup is essential for validating fusion plasma models.

Purpose of the Study:

• To experimentally determine the time-integrated triton burnup ratio in deuterium plasma within the KSTAR tokamak.
• To compare experimental burnup data with theoretical predictions based on triton prompt loss and slowing-down times.

Main Methods:

• Simultaneous detection of deuterium-deuterium (d-d) and deuterium-tritium (d-t) neutrons using various detectors (³He proportional counter, fission chambers, activated indium, silicon, and copper samples).
• Calculation of prompt triton loss fraction using the Lorentz orbit code.
• Estimation of classical triton slowing-down time.

Main Results:

• Triton burnup ratios in KSTAR discharges ranged from 0.01% to 0.50%, varying with plasma conditions.
• An increasing trend was observed between the measured burnup ratio and both plasma current and classical slowing-down time.

Conclusions:

• Experimental measurements provide crucial data for validating fusion plasma simulations.
• The findings suggest that plasma current and slowing-down time are key factors influencing triton burnup in tokamaks.