Speakers
Dr
Alexander Usoskin
(Bruker HTS GmbH)Mr
Tim Bubelis
(Bruker HTS)
Description
Employing a newly developed compact pilot pulsed laser deposition (PLD) machine that is based on 308nm-excimer laser we manufactured 40-80 m long coated conductors (CCs) aimed for demonstration and prototyping. Both a single beam and a double beam deposition PLD regimes were tested.
The PLD installation was substantially based on “helical” technology of tape translation, “black-cavity” tape heating, and smoothed target ablation developed earlier by Bruker and improved further in the present equipment. Stainless steel tapes buffered via alternating-beam-assisted deposition (ABAD) of yttria stabilized zirconia layer were implemented as a substrate material. The polished substrate tapes and ABAD buffers were also manufactured in the pilot line of "compact" class. CeO2 buffer cap layer was deposited onto the tape in situ, via PLD prior to HTS layer. A silver protection layer and thick Cu layer were deposited by vacuum thermal evaporation and galvanic plating, respectively. Above 100A (or >250A/cm-width) critical currents were measured in 4mm wide coated conductors at 77K and self-field. Maximal critical current achieved in the best quality tape was 410 A/cm-width. Inhomogeneity of critical current detected using a magneto-scan did not exceed 5%. At optimized conditions, the Ic-inhomogeneity may be suppressed further, down to 2%. A possibility to increase PLD throughput above 30 m/hour in multi-beam modus was demonstrated. Advantages and feasibility of compact-scale equipment in process/ device prototyping and flexible pilot production are discussed in terms of processing costs and processing yield.
Author
Dr
Alexander Usoskin
(Bruker HTS GmbH)
Co-authors
Mr
Alexander Rutt
(Bruker HTS GmbH)
Mr
Reinhard Dietrich
(Bruker HTS GmbH)
Mr
Sergey Shavkin
(NRC Kurchatov Institute)
Mr
Tim Bubelis
(Bruker HTS)
Dr
Victor Pansyrny
(Russian Superconductor JSC)
