Development of inside-plume PLD process for the fabrication of large Ic(B) REBCO tapes

We developed an inside-plume pulsed laser deposition (IP-PLD) technique which has enabled high-rate fabrication of Gd-Ba-Cu-O (GdBCO) tapes with improved transport current capability. The main idea of the IP-PLD technique is to increase the deposition rate simply by reducing the substrate-to-target (ST) distance and to employ very high laser energy density, >0.035 J/mm2. As a result, the production rate increased up to about three times higher than that for the conventional PLD method. We also showed that the IP-PLD requires appropriate adjustment of the target composition to obtain an optimal composition in the tape. By optimizing the target composition and adding BaZrO3 pinning centers, we obtained very high Ic values at 77 K of 700–1000 A/cm-w (s.f.) and 135 A/cm-w (B = 3 T (B‖c)) for short samples with an about 5 μm-thick GdBCO layer.