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High-temperature superconducting (HTS) magnets are emerging as key R&D components for compact and economical future fusion devices. Institute for Plasma Research (IPR), India, has undertaken an R&D initiative focused on the design and development of fusion-relevant HTS magnets. This initiative covers the development of compact solenoids and D-shaped magnets and dedicated test facilities. As a part of this effort, the design, fabrication, and testing of a D-shaped HTS magnet with dimensions of 1.1 m in height and 0.7 m in width have been completed. This magnet comprises a vacuum-jacketed liquid nitrogen chamber housing the HTS winding pack. The winding pack terminations of this coil are electrically connected with a pair of liquid nitrogen-cooled copper current leads for interfacing with the power supply. The winding pack is composed of a double pancake with 12 turns of stacked-type REBCO HTS cable in a layered configuration. The fabrication of the winding pack of magnet is carried out using dry FRP tape insulated HTS cable with in-house setup using LN2 casing bottom section as a mandrel to achieve the required D shape profile. The voltage taps and PT-100 temperature sensors are installed on the winding pack at critical locations. The winding pack is then encapsulated by welding the remaining section of the LN2 casing which is further inserted and encased in a D-shaped vacuum chamber of volume 0.05 m3. This D-shaped magnet has been successfully tested at 77 K, up to 1.2 kA. The design parameters, fabrication processes, test results, and the technical difficulties faced during the development of this magnet will be discussed in this paper.
