Haruhiko Okumura
<okumura@matsusaka-u.ac.jp>
Satarou Yamaguchi
<yamax@YSL.nifs.ac.jp>
1996 Applied Superconductivity Conference
Pittsburgh Convention Center
Pittsburgh, Pennsylvania
August 25-30, 1996
Current leads, which connect superconducting magnets at the liquid helium temperature and power supplies at the room temperature, are the major source of heat leaking into cryostats, and therefore largely determines the running cost of magnet systems. Heat leak can be reduced by using high-temperature superconductors as the low-temperature (4K--77K) segments of current leads. Another method to reduce heat leak, recently proposed by one of us (S.Y.), uses Peltier thermoelectric elements as the high-temperature (200K--300K) segments of current leads. These thermoelements effectively pump heat out of cryostats without using separate sources of electricity. We carried out experiments and numerical calculations with such Peltier current leads and found out that they reduce heat leak at 77K by 20--30 percent.