Thermodynamic optimization of the cryostat for Nb/sub 3/Sn superconductors thermal research

NED activity within work package TSQP includes a task to study the thermal behavior of new ceramic electrical insulation. This insulation with good wrapping and excellent thermal resistance during heat treatment would eliminate complex coil fabrication, lower cost and reduce fabrication time. Tests of the insulation's thermal features require a superfluid helium cryostat. The cryostat is constructed at Wroclaw University of Technology in co-operation with CEA and CERN. Heat transfer measurements should be realized in saturated He I (4.2 K), in supercritical He (4.2...5 K, 1...6 bar), and in pressurized He II (1.9 K, 1 bar). The cryostat thermal insulation has been optimized on the basis of the generated entropy minimization method. The total heat flux to the super-fluid helium has been estimated at 3 W. The cryostat, after the tests done at Wroclaw University of Technology, will be delivered to CEA, Saclay to perform thermal measurements of the insulation.