The history and general principle of Stirling Engine are briefly discussed. The several points of problem regarding this engine at the present stage and the future applicational probability are shown. This short report is written basing on the author's visit to Philips Res. Lab. at Eindhoven about 4 years ago.
This article introduces the cryogenic power cable, especially its thermal and electrical insulations. These are important matters on the reliability of cryogenic cables. Thermal insulating methods for cables are similar to general cryogenic vesseles. However the length of the cable makes some troubles in evacuation, formation, etc. The applications of thermal insulating methods are discussed with the examples of several plants. Electrical insulating materials at low temperature have been researched in these few years. Solid materials have no reliability because of thermal cracks. Polyethylene paper laminated insulation impregnated with liquid nitrogen has good performance for liquid nitrogen cooled cable. For the superconductive cable, supercritical helium impregnated tape-type insulator seems promissing as electrical insulating methods.
A concentric double solenoid magnet, which can generate a magnetic field up to 10T, is constructed with V3Ga, Nb3Sn, Nb-Ti materials. The Nb3Sn tape of the least current density is put on the extreme parts of the inner solenoid to avoid the magnetic instability due to perpendicular field. The magnet quenches regularly at the limit of current capacity in both solenoids. It is observed, as expected, that the influence of magnetization in the internal solenoid is important on field distribution even by charging only the external solenoid. The residual field and the field distribution at increase or decrease of current are measured on the axis at several conditions, charging only the external solenoid, only the internal solenoid or the both.