Composition optimization Bi2Sr2CaCu2Ox powder for high JE multifilamentary wires for high field magnets

High field magnets exceeding 16 Tesla (T) are crucial components in advancing high-energy physics research, particularly for next-generation accelerators and upgrades to existing facilities. Among the most promising materials for realizing such magnets are multifilamentary round Bi-2212/Ag wires, boasting exceptional properties including high irreversibility fields, isotropic electromagnetic performance, solenoid layer winding capabilities, and the highest engineering critical current density (JE) at fields surpassing 20 T. However, the widespread application of Bi-2212/Ag wires is hampered by the limited availability and high cost of long continuous lengths of conductors. To address this challenge, this proposed project focuses on developing a scalable process for manufacturing powders tailored specifically for Bi-2212/Ag wires. The primary objective is to facilitate the production of high-performance, long-length wires essential for high field magnets in high-energy physics applications. In the Phase I feasibility study, a chemical precipitation method was successfully employed to synthesize precursor powders, followed by controlled low-pressure calcination and heat treatment processes to achieve desired phase purity and stochiometric control. Phase I optimization efforts targeted minimizing processing time and temperature to mitigate the formation of hard aggregates, which detrimentally affect wire performance during the drawing process. Building upon the success of Phase I, Phase II will refine and scale up the proposed approach to meet the demand for long-length wires (~1 km). This scaling up involves the development of semi-automated chemical precipitation equipment and the fabrication of customized furnaces for heat treatment. The focus will be on producing reliable and cost-effective powders suitable for long length Bi-2212/Ag multifilamentary wires. Efforts will also be directed towards further optimizing the powder composition and its characteristics like particle size and morphology to enhance the current carrying ability (JE) of the wires. Long-length wires will be fabricated at BOST, followed by heat treatment utilizing oxygen overpressure, and subsequent evaluation at NHMFL, FSU. Additionally, short multifilamentary wires will be produced at Navaflex for process and composition optimization purposes. The proposed project represents a crucial step towards overcoming the limitations hindering the widespread adoption of Bi-2212/Ag wires for high field magnets in high-energy physics applications. By establishing a reliable source of powders with defined properties and optimizing wire fabrication processes, the project aims to significantly enhance the performance and accessibility of Bi-2212/Ag wires, ultimately advancing the capabilities of next-generation accelerators and contributing to the broader scientific community's pursuit of fundamental discoveries in particle physics.