Reactive Co-Evaporation by Deposition and Reaction (RCE-DR) is a unique process to produce REBa₂Cu₃O_7-δ (REBCO) high temperature superconducting (HTS) wires in SuNAM. The RCE-DR process has a high throughput (120 m/h in 12 mm-width) leading to a low fabrication cost. The REBCO HTS wires manufactured by the RCE-DR process show a world-class critical current (>750 A/12mm-width) at 77 K, self-field. On the other hand, an in-field performance of those does not meet needs of superconducting markets, especially high-field magnet applications. We recently have put in new RCE-DR equipment with 100 kW class E-gun for increase of in-field critical current. E-gun with higher power allows more sources to consistently co-evaporate. Consequently, we have added ZrO₂, HfO₂, etc. to a REBCO superconducting layer in order to formation of artificial pinning centers (APCs). We have investigated how newly introduced APCs are distributed throughout REBCO superconducting layer and how they interplay with self-pinning center (RE₂O₃). We will discuss the improvement of the critical current in magnetic field and the microstructure of the REBCO superconducting layer with the APCs by transmission electron microscopy images in this presentation.

Acknowledgments
This work supported by Nano-Convergence Foundation funded by the Ministry of Science and ICT (MSIT, Korea) & the Ministry of Trade, Industry and Energy (MOTIE, Korea) [Development of high-TC superconducting wire through improvement of engineering critical current density / R201902010]

Keywords: RCE-DR, REBCO, pinning center, in-field critical current