Researchers have conducted a comprehensive review of cooling systems and power conversion technologies applicable to tokamaks, identifying key engineering challenges for future fusion power plants. The study critically examines various coolant options, including water, helium, and liquid metals, assessing their suitability for heat extraction from the plasma-facing components and superconducting magnets. The paper emphasizes the necessity of efficient heat transport and conversion to electricity to achieve a viable net energy output from fusion reactors.

The selection of an appropriate coolant is paramount, influencing the design of the primary heat transport system and the overall thermal efficiency. Water, while well-understood, faces limitations in high-temperature applications and potential activation issues. Helium offers inertness and high-temperature capability but requires complex handling systems. Liquid metals, such as lithium or lead-lithium eutectic, provide excellent heat transfer properties and potential tritium breeding capabilities but introduce material compatibility and safety concerns.

The selection of an appropriate coolant is paramount, influencing the design of the primary heat transport system and the overall thermal efficiency.

The power conversion system (PCS) is equally critical, translating the thermal energy captured by the coolant into electrical power. The review discusses conventional steam cycles, gas turbine cycles, and advanced concepts like supercritical CO2 cycles. Each approach presents distinct advantages and disadvantages regarding thermal efficiency, footprint, and integration complexity with the fusion core. Optimizing the PCS is essential for maximizing the net electrical output of a fusion power plant.

The paper highlights that the integration of the cooling system and the PCS is a complex engineering task. Heat losses, pumping power requirements, and material degradation over time must be carefully managed. Achieving high overall plant efficiency requires a holistic design approach, considering the interplay between the fusion core, heat transport, and electrical generation subsystems. This review provides a valuable resource for designers and engineers working on the next generation of fusion devices.

Future research should focus on developing advanced materials capable of withstanding the harsh fusion environment and high heat fluxes, as well as on optimizing the thermal hydraulics of coolant loops. Further investigation into the integration of tritium breeding blankets with the primary cooling systems is also crucial for D-T fuel cycle reactors. The development of robust and efficient power conversion technologies will be a key determinant in the commercial viability of fusion energy.