Minimum Quench Energy of Nb3Sn Wires With High Specific Heat Tape

A major problem of state-of-the-art Nb
₃
Sn accelerator magnets is their long training due to thermo-mechanical perturbations. Increasing the specific heat,
C_p
, of the Rutherford cable would reduce and/or eliminate training by limiting the coils temperature rise. This paper studies feasibility of increasing the
C_p
of Rutherford-type cables by using thin composite Cu/Gd
₂
O
₃
and Cu/Gd
₂
O
₂
S tapes produced by Hyper Tech Research, Inc. The tape can be either wrapped around the cable, placed on the cable wide faces under the insulation, and/or inserted as a core. Wire samples outfitted with these high-
C_p
ribbons, or tapes, were prepared and tested at FNAL for their Minimum Quench Energy (
MQE
). At 90%
I_c
and 15 T, the average gain of
MQE
of the Nb
₃
Sn wire soldered to the Cu/Gd
₂
O
₂
S 55 μm thick ribbon was 2.5, and further increased at larger transport currents.