The conceptual design of the soft x-ray tomography for the DTT

Abstract

DTT, the Divertor Tokamak Test facility, currently under construction at ENEA in Frascati (Rome, Italy), is a fully superconducting tokamak. DTT is a medium-sized experimental fusion reactor designed to test new divertor and plasma control technologies for use in larger, fusion reactor-scale devices such as ITER and DEMO. This work focuses on the conceptual design of Soft X-ray tomographic system for DTT first phase, when the machine is expected to operate with up to 17.5 MW of total injected power The diagnostic layout has been developed to optimize the tomographic reconstruction of emissivity distributions using Tikhonov-Phillips regularization techniques. Measurement arrays are positioned within each of the four access ports of a single toroidal sector, with their lines of sight (LoS) cover the entire poloidal cross-section of the vacuum vessel. This configuration is essential to ensure accurate tomographic reconstruction, which is useful for analyzing and monitoring plasma behavior. A large effort has been devoted to defining the best layout for the mechanical supports and their positioning, to ensure compatibility with the other systems located in the same ports. The selected detectors for this diagnostic are grown Chemical Vapor Deposition (CVD) diamonds, which offer significant advantages over traditional solutions, including high radiation hardness, increased mechanical robustness, and the ability to operate at elevated temperatures and pressures.