It is very likely that our group is the only academic institution in the U.S. with complete facilities for thin film superconductor wire manufacturing. We have established a reel-to-reel (R2R) pilot-scale advanced metal organic chemical vapor deposition (MOCVD) tool (Figure 1) to scale up our high-performance superconductor tapes. This system is being used for conducting manufacturing research and includes features such as a meter-long deposition zone, dual high capacity evaporators, dual high capacity pumping system, in-line 2D X-ray Diffraction (Figure 1) for real-time information on crystallographic orientation of superconductor film growth and in-line vision system for real-time detection and tagging of defects in the film. We have demonstrated 50-meter-long superconductor tapes with 3x the critical current of industry tapes. This is an excellent example of transitioning laboratory-scale research demonstrations to manufacturing and our record in securing a multi-million dollar projects to execute this scale up. The pilot Advanced MOCVD manufacturing tool is now being upgraded for multi-track deposition to increased tape throughput.
Figure 1. (Above) Pilot-scale MOCVD tool for superconductor wire manufacturing at our facility (Below) In-line X-ray 2D Diffraction system in the MOCVD manufacturing tool for real-time quality control
Two research-scale R2R Advanced MOCVD tools are also available for further advancements of superconductor tape technology including double-sided tapes and high precursor-to-film conversion efficiency. The Advanced MOCVD tools are based on a novel reactor design that includes direct tape heating, direct temperature monitoring, laminar flow channel and plasma activation. The novel features provide excellent stability of film growth temperature, precursor composition as well as high precursor-to-film conversion efficiency. Record-high performance levels have been demonstrated using the Advanced MOCVD tool. A photograph of the Advanced MOCVD tool is shown in Figure 2.
Figure 2. Reel-to-reel research-scale Advanced MOCVD tool
In addition to our several MOCVD tools, in 2024 we will be installing a reel-to-reel PLD tool for REBCO and buffer deposition. This tool is being procured through a DURIP award we received in 2023. The PLD tool consists of reel chambers for reel-to-reel continuous deposition, 33 W excimer laser, target manipulator to hold three 4″ diameter targets and capable of uniform ablation, and an intelligent optical window to avoid excessive coating of the laser optics.
A reel-to-reel system for electropolishing of substrates and electroplating system of copper stabilizer is available in our facility (Figure 3). The reel-to-reel electroplating system is utilized to deposit copper stabilizer on long superconductor tapes. It can be used for electroplating of other materials as well.
A reel-to-reel system for magnetron sputtering of silver overlayer on superconductor wires are available at our facility (Figure 4). This system can be used for magnetron sputtering of other materials as well, on a manufacturing scale.
Figure 4. Reel-to-reel system for magnetron sputtering of silver
In addition to manufacturing tools for processing, we have designed, constructed and commissioned novel reel-to-reel quality assurance tools for verification of quality of long superconductor wires. One such tool is a reel-to-reel in-field critical current measurement system (Figure 5) where critical current of long superconductor tapes is measured in a magnetic field of 5 Tesla. This equipment provides unique performance data that is important for verification of uniformity of quality of superconductor tapes in many applications but has not been available even in industry. Using know-how that was developed in our research laboratories, we established this innovative tool to qualify long tapes that are produced in our manufacturing research as well as those made in industry.
Several advanced metrology tools are available including Bruker D8 X-ray Diffractometer with area detector (2D-XRD), Renishaw Raman Analyzer, Agilent Inductively Coupled Plasma Spectroscopy (ICP-MS), Stylus and Optical profilometers. A Physical Property Measurement System (PPMS) capable of magnetization and susceptibility measurements from 4.2 K to 77 K in magnetic fields up to 14 T is available. Mechanical property measurements are conducted using a peel-test apparatus and two load frames for tensile and torsion testing at a77K with transport current.
A Bruker Skyscan 2214 micro-CT system is also available in our laboratory. Key features of the system are <500nm real nominal resolution, up to four detectors – each providing optimum range of size/density/resolution, maximum object size of 300 nm and the fastest 3D reconstruction.