12. Super conducting transformers
12.3 Refrigerating
To produce fine diameter of filaments, metal super conductive materials are only applicable by today's technology. These have to be kept in liquid helium level temperature (4K) for keeping super conductivity. Theoretically the efficiency of the refrigerator to produce such temperature is extremely low and practically furthermore low (in the order of 1/500 --- 1/1000). That means to refrigerate 1kW of loss, 500 --- 1000kW of electric power is necessary.
This page is based on Prof. E.Haginomori's lectures
in Tokyo Institute of Technology, and edited by Japanese ATP User Group.
Copyright (C) Eiichi Haginomori and Japanese ATP User Group.