Speaker
Description
Bi-2212 conductors and accelerator magnets have been advanced in the USA through a collaboration between US national labs, university, and wire industry connected by the US Magnet Development Program (MDP) and by recently the U.S. Department of Energy’s Accelerator R&D and Production (ARDAP) Office. For example, a high engineering critical current density of 1000 A/mm2 has been demonstrated at 4.2 K and 27 T. Canted-cosine-theta coils have been made from Bi-2212 Rutherford cables and tested as a dipole magnet; the fabrication scheme and an initial performance benchmark have been established. Here in this talk we will summarize key findings and results under a two years' ARDAP project, which aims to advance conductor manufacturing and various aspects of coil technologies relevant for accelerator magnets with complimentary efforts and coil development from US MDP. We will discuss results of ARDAP conductor development that fabricates eight 2 kg conductor billets, which targets for establishing key powder characteristics and wire performance relationships and improve produce consistency and yield. Among the eight billets, there are two billets produced in 0.7 mm and fabricated as a Rutherford cable; a billet was produced in usual wire architecture and 0.8 mm but encased in a thicker Ag-0.2wtMg sheath. The wires also receive various modifications to thermo-processing to improve understanding of wire production. We will also discuss new understanding of Bi-2212 Rutherford cable fabrication and causes of ceramic leakages revealed in this collaborative effort.
