open discussion

1. Open discussion on
Thermal transfer efficiency
 Thermal conductivity vs Kapitza : what is dominant ?
 Influence of temperature range (2 K vs 4 K , and even higher at hot spots)
 Cooling cavities vs cooling parts (e.g. couplers ) external to the He
Tank => different requirements ?
 Role of interfaces
 Grain boundaries : small grain vs LG
 Thin film, multilayers
 Electronic nature (oxide/metal/contaminn)
 Surface roughness :
 What scale is important ?
 Should we machine the external surface ?
 Or put a special (porous) layer ? …
http://www.sciencedirect.com/science
/article/pii/S1388248104003066
THSRF 2014 Legnaro