*A. Molodyk^1,2, S. Samoilenkov^1,2, V. Petrykin ³, S. Lee ^3
1S-Innovations, Moscow, Russia; ²SuperOx, Moscow, Russia; ³SuperOx Japan, Kanagawa, Japan
Over the recent years, the SuperOx team—S-Innovations located in Russia and SuperOx Japan—have earned recognition as world leading manufacturers of 2G HTS wire. In this talk we will describe the material, give an overview of the processing technologies, and present the status of SuperOx 2G HTS wire manufacturing facilities and wire performance. SuperOx 2G HTS wire is a multi-layered long tape based on the mechanically strong Hastelloy substrate, onto which several thin oxide layers are deposited, the so called buffer layers of the overall thickness of 100-150 nm, and then a 1-3 micron thick REBa₂Cu₃O₇ high temperature superconducting layer is deposited by PLD. The wire architecture is finished with a sputtered silver layer and an electroplated copper layer. We have been incrementally increasing our production capacity, to reflect the increasing demand on wire. In 2020, the overall capacity at SuperOx was 300 km of 12 mm wide wire per year and we keep increasing it further, to reach 1000 km per year in Q3 2021. There are two lines of product: “wire for LN2” intended for application at liquid nitrogen temperature (77 K) and “wire for in-field use” intended for application at low temperature in magnetic field. For wire for LN2, average I_c at 77 K in self-field is at 600 to 800 A/12 mm, depending on the HTS layer thickness, and the I_c standard deviation is 1-3%. The performance of the wire for in-field use at 77 K is at 450-600 A/12 mm and the I_c standard deviation is 2-5%. The wire for in-field use, however, offers an I_c at 20 K, 20 T of 150-250 A/4 mm and an I_c at 4.2 K, 20 T of 400-500 A/4 mm, which at present are the highest values for commercially available wire to the best of our knowledge. Wire for in-field use on a 40-micron-thin substrate in combination with 5 microns per side surround copper stabilisation results in a product with a record high engineering current density of over 1000 A/mm² at 20 K, 20 T and over 2000 A/mm² at 4.2 K, 20 T.