Minimum Quench Energy measurements on prototype LHC inner cables in normalhelium at 4.4 K and in superfluid He at 1.9 K

The minimum energy of short duration (MQE) required to quench superconducti ng cables at fixed field for currents close to the critical current has bee n measured for several prototype LHC inner type cables. Measurements done b oth in normal helium at 4.4 K and also in superfluid helium at 1.9 K show t hat the level of cable compaction has a substantial effect on the conductor stability. It also appears that another parameter that significantly influ ences the ability of the conductor to absorb transient energy pulses is the inter-strand resistance, which can vary greatly depending on the cable des ign and the nature of the strand surface. This parameter seems to make a bi gger difference to MQE at 1.9 K than at 4.4 K, Details of these measurement s are presented.