The development of a high-temperature superconducting magnetic sensor (SQUID) has been reported. It is relatively easy to handle in comparison with a Nb SQUID because it can work at liquid nitrogen temperature. This high Tc SQUID has great potential for application in medical diagnostics, nondestructive tests and geological survey, and in other areas. Recently a single channel of the high Tc SQUID was placed on the market. It is expected that this SQUID will accelerate the development of SQUID applications.
The superconducting magnet levitation railway system will make its debut as a new high-speed mass transport system in the 21st century. In conjunction with the Central Japan Railway Company, the Railway Technical Research Institute (RTRI) started test running of the system in April 1997 on the Yamanashi Test Line. Eight months thereafter, or in December 1997, the test vehicles recorded the world's highest speed of 550km/h, which had been the first target of the development. Various tests related to the system are successfully being promoted to verify the high technical level attained so far. This paper outlines the developmental processes of the superconducting magnet, on-board refrigeration system, and other cryogenic systems; reports the results and operation during the past year; and introduces some of the key technologies that led to the unprecedented speed of 550km/h.
The mechanical properties of superconductors such as Young's modulus and yield strength, are very important for their applications. There has been an urgent need to test the mechanical properties, but no standard method exists worldwide. We have discussed, evaluated through a round-robin test, and standardized the method of room temperature tensile tests for Cu/Nb-Ti composite superconductors because Cu/Nb-Ti composite is now the most popular superconductor. This paper provides critical examination of this method and is concerned with double-yielding phenomena, strain measurement, reliability, and accuracy, which are the items to be elucidated. The first draft is prepared and submitted to IEC/TC90 as an international standard. It will soon be issued as International Standard IEC61788-4.