KAPITZA RESISTANCE AND THERMAL-CONDUCTIVITY FOR NIOBIUM

The use of superfluid helium as a refrigerant of niobium superconducti ng cavities in several great particle accelerators' projects gives mor e interest to the measurement of the Kapitza resistance (or the Kapitz a conductance) of niobium with different purity and surface treatments . Two experimental setups are presented here one allowed for the measu rement of the Kapitza resistance and the other for thermal conductivit y of niobium. They have been tested successfully with copper for which there are several available data. Results are given for niobium ''Her aeus'' with different surface treatment and for temperatures ranging f rom 1.4 K to 2.15 K.