A new transistor-like superconducting three terminal device called “Quiteron” is briefly reviewed. The article contains the basic concept of quasiparticle injection phenomena in a superconductor including the expected behavior both in the stationary state and in the transient state as well as the operation of Quiteron itself with or without external load. The factors which limit the ability of Quiteron are also discussed.
Electro-magnetic thruster is one of the ship propulsion methods in which the thrust is resulted from the interaction between magnetic field generated by the fixed magnet on the ship and electric current sent to the seawater. Consequently, the thrust is generated without any rotational parts such as a propeller. But this propulsion method requires high magnetic field density so that we have been trying to apply the superconducting coil to the electro-magnetic propulsion since 1973. In 1976, the first electro-magnetic propulsion model ship in the world, which was equipped with a small superconducting coil, was built and fundamental experiments has been carried out in our laboratory. We confirmed from the experience that superconducting magnets are essential to the propulsion method. In 1979, the second model ship of superconducting electro-magnetic thruster, ST-500, was built. The model ship is 3.6m in length, 700kg in weight and about 2 teslas in magnetic field. Our study on ST-500 has been evaluaed in the ship building world and invited to the international propeller conference held May, 1983. This article was prepared based on the paper presented in the conference.
The absolute ampere A would be actualized using two kinds of the gyromagnetic ratio of proton γp′ (low) and γp′ (high), which are measured by low and high magnetic field methods respectively with the maintained ampere. In the high magnetic field method, we measure the flux density B by weighing the force which acts on a rectangular coil, through which a known current is passing, in a magnetic field. In order to determine A with the uncertainty less than 1ppm (parts per million), the split type superconducting magnet with a wide homogeneous range better than 1ppm over 100mm length is needed. As a preliminary experiment, we have developed a small and split type superconducting magnet with the homogeneity better than 10ppm over 10mm. The dimensions are 155mm in diameter, 25mm in gap interval and 100mm in total length. A helmholtz type main coil and compensating pair coils were wound on the bobbin which was made of stainless steel SUS304. The main coil was connected to the compensating coils in series as usual. The measured homogeneity of magnetic field was less than that obtained from a calculation with the dimensions. It has been clearified that the inhomogeneity was caused by the magnetization of a part of weld in the bobbin. However the inhomogeneity is reproducible. In order to improve the inhomogeneity, the compensating coil are remade and the remade coils are