Site:           National Research Institute for Metals (NRIM)
                1-2-1, Sengen, Tsukuba-shi
                Ibaraki 305, Japan
                http://www.nrim.go.jp/
Date Visited:   5 June 1996
WTEC Attendees: R. Sokolowski (report author), 
                R.D. Blaugher, 
                J. Daley, 
                P.M. Grant, 
                H. Morishita, 
                R. Schwall, 
                J. Willis
Hosts:          Dr. Kazumasa Togano, Director, 
                   1st Research Group (Superconducting Materials)
                Dr. Hitoshi Wada, Research Dir., 
                   Tsukuba Magnet Laboratories

BACKGROUND

The National Research Institute for Metals (NRIM) was established forty years ago as an organization attached to the Science and Technology Agency (STA). Of the 450 people working at the two NRIM campuses (Tsukuba and Sakura), 300 are active researchers; the balance provide administrative and other support functions. NRIM's overall research budget for fiscal 1996 was approximately ¥3.9 billion. The budget for superconducting materials, which represents about one-third of the total research budget of NRIM, grew from ¥1.38 billion in 1993 to ¥1.63 billion in 1995. The weakening of the dollar from ¥122 to the dollar in 1995 to ¥105 in 1996 exaggerates this growth when expressed in dollars ($11.3 to $16.3 million). STA conducts an annual review of NRIM activities, but there is no industrial oversight committee such as the one that oversees progress at the DOE laboratories; consequently, there is no evaluation of the commercial worth or applicability of NRIM research, although the work done is clearly relevant to long-term industrial goals. Applications for intellectual property protection are handled by the Japan Science and Technology Corporation (JST).

SUPERCONDUCTIVITY RESEARCH

About thirty NRIM researchers work on superconductivity (only three on low temperature superconductors, Nb₃Al and multifilamentary V₃Si). Drs. Takeuchi and Inoue at Tsukuba Magnet Laboratories work on Nb₃Al. Collaborative work with industry (e.g., Hitachi and Showa) has been quite good, with results published openly and jointly in peer-reviewed scientific journals; however, some NRIM activities may be regarded by those with whom they do not collaborate (e.g., Fujikura) as being competitive. Collaboration with industry is handled typically on a "no-funds-exchanged" basis, with each party responsible for its own costs, and there is no mechanism for NRIM to receive funds from private sector companies.

Within NRIM's First Research Group headed by Dr. Togano, which is devoted to superconducting materials, there are four subgroups: (1) one headed by Dr. Kumakura looking at wires and tapes; (2) one headed by Dr. Hirata looking at more fundamental aspects such as the physics of mixed states using single crystals; (3) one headed by Dr. Nakamura looking at thin film physical growth mechanisms and device applications, and (4) one headed by Dr. Fukutomi looking at thin film processes for wires and tapes. This latter group is not using ion beam assisted deposition, but is developing novel cathodes for magnetron sputtering. Whereas nearly all work in superconductivity is done at Dr. Togano's First Research Group, there is also some materials and coil development being carried out at the High Magnetic Field Research Station. Because NRIM is a government institution, many of the more commercially oriented questions that WTEC panelists posed to NRIM were not relevant and hence were not answered.

Multicore Superconductivity Project

The overarching program objective today for superconductivity research at NRIM is derived from the second phase of the STA Multicore Project, which runs from 1995 to the year 2000. NRIM receives the largest share of Multicore Project funds, and all four groups mentioned above receive financial support from this project. Funding for the Multicore Project is fixed over a five-year period. Although program objectives are clearly defined, flexibility exists such that technical directions can be changed if necessary, and replanning is possible within and among groups and divisions. There is also the possibility of additional funding should a sufficiently provocative discovery warrant a request for an unbudgeted increment to pursue the new scientific or technical development. The two applications this project has targeted for development are an insert magnet for a 1 GHz NMR system and a magnetic separation unit that is being pursued in collaboration with MITI's Electrotechnical Laboratory (ETL). The WTEC team's hosts mentioned that the large-scale installation of NMR systems at Riken in Saitama is highly dependent on the success of the 1 GHz project. The magnetic separation project -- the magnet will have a warm bore of about 15 cm and generate several tesla -- has a practical goal of assisting in the cleaning of nearby Kasumigaura Lake. In spite of rapid advances in recent development of coated conductors with enhanced current-carrying performance, NRIM researchers feel that BSCCO-2223 is still the best candidate through the next five years for achieving the high performance target of 100,000 A/cm² in long lengths.

Superconductivity for Electric Power Applications

Since the technical focus of the Multicore Project is aimed at NMR spectroscopy and magnetic separation, only the more fundamental and performance-enhancing aspects of conductor-related research will be relevant to electric power applications. In these terms, the fiscal 1996 budget for HTS/LTS power applications was about ¥284 million, and the number of researchers was 13 (10 in HTS and 3 in LTS). The budget distribution for these two applications for 1995 and 1996 is as follows:

  Year      NMR             Magnetic Separation
  1995      ¥170 million    ¥72 million 
  1996      ¥170 million    ¥110 million 

Funding for the balance of the project is expected to continue at this rate until completion of Phase II in 1999.

Conductor and Materials Development

Nearly 10% of NRIM's superconductivity budget (~¥100 million) and 70% of the staff in superconductivity (20 people) are applied to conductor and materials development. External organizations collaborate by sending researchers to NRIM and by winding coils. NRIM's role is to establish basic technology and make available its materials characterization facilities. Most scientists at NRIM are engaged in the study of BSCCO-2212, although there is some work being conducted on BSCCO-2223 and YBCO. Conductor geometries being studied include monocore, multifilamentary, and also coated tapes. The performance levels NRIM researchers have been able to achieve in these various systems are well documented in the scientific literature. Their major scientific and technical issues concern improving (1) uniformity and reproducibility of J_c along the tape length, (2) mechanical properties, and (3) high-temperature characteristics of the Bi-system. They see process optimization as the solution to item (1), since it is believed that inclusions randomly situated along the length of HTS tapes limit the uniformity of J_c. Silver alloys are also being used to address the mechanical properties issue; however, the price of a sharp improvement in strength of either the silver sheath or substrate is a degradation in J_c.

NRIM is doing no work on bulk materials or ac losses.

Power Generation, Storage, Transmission & Distribution

NRIM has no R&D programs in these areas.

End User Applications

About 10% of the superconductivity budget and manpower (¥110 million and three researchers) are applied to end user applications, mainly for magnetic separation in collaboration with ETL, which is doing the system development. NRIM's contribution to this program is magnet development. System designs and operating parameters have not yet been decided, but preliminary coil tests are being conducted. The major technical issue is the construction of a large-bore HTS magnet operating at higher temperature with either a cryocooler or liquid nitrogen. NRIM officials believe that there can be a market for high field magnets if HTS materials, which have higher upper critical fields than LTS conductors at low temperatures, can help produce high magnetic fields that lie outside the range achievable by LTS materials alone. The time to market is estimated to be anywhere from five to ten years. Depending on the frequency (resolution) required, LTS can handle systems up to 900 MHz, whereas systems greater than 1 GHz will require hybrids incorporating both LTS and HTS materials. No detailed comments were available for target costs or markets; however, the expectations for HTS products in the marketplace are as follows:

5 years -- current leads
10 years -- NMR, magnetic separation, cables, sensors