CERN EUCARD WP 7 Task 4 Round Robin

CERN, EUCARD WP 7 -Task 4 Round Robin Test for Ic measurements of Nb-Ti and YBCO conductors (EUCARD WP 7 task 4)WP 7 Jerome Fleiter (CERN, University of Grenoble)

• Laboratories involved – – – INFN-LASA (Milano) UNIGE (Geneva) CEA (Saclay) CNRS (Grenoble) CERN (Geneva) • 2 Samples measured at 4. 2 K – Nb-Ti LHC strand mounted on a LHC barrel at CERN. – YBCO tape from Super. Power, mounted on a barrel at INFN - LASA.

Nb-Ti @ 4. 2 K Ic using 0. 1μV/cm criterion (Sample 02 R 00056 A 01 UX. 129) 2000 UNIGE 4. 19 K 0. 1μV/cm 1800 INFN LASA 4. 22 K 0. 1μV/cm 1600 CERN 4. 26 K 0. 1μV/cm 1400 Ic (A) 1200 1000 800 32 mm 600 400 200 0 0 2 4 B (T) 6 8 – No correction of field – No correction of temperature 10

Nb-Ti @ 4. 2 K Ic using 1μV/cm criterion (Sample 02 R 00056 A 01 UX. 129) 2000 UNIGE 4. 19 K 1μV/cm 1800 INFN LASA 4. 2 K 1μV/cm 1600 CERN 4. 26 K 1μV/cm 1400 1000 800 600 400 200 0 0 2 4 B (T) 6 8 10 Without temperature correction, measurements are already within 4%. n-value Ic (A) 1200 80 70 60 50 40 30 20 10 0 UNIGE INFN CERN 0 5 B (T) 10

YBCO @ 4. 2 K Ic data using 1μV/cm criterion compared to a fit (Spool SP-20100108 -1 sample 01) 1600 LASA 4. 25 K 1μV/cm 1400 UNIGE 4. 19 K 1μV/cm 1200 Fit Ic (A) 1000 800 600 400 200 0 0 5 10 15 B (T) 20 25 30 – No correction of field – Engineering Critical current density at 19 T is 2400 A/mm 2 (B//ab plane) 35

YBCO @ 4. 2 K Spool SP-20100108 -1 sample 01 (Ic @77 K, s. f. =102 A) 51, 6 UNIGE n-value 51, 4 n-value 51, 2 51 50, 8 50, 6 50, 4 50, 2 17, 3 17, 5 17, 7 17, 9 18, 1 18, 3 18, 5 18, 7 18, 9 19, 1 B (T) n-values are high. Sharp transition takes place.

YBCO @ 4. 2 K Ic performance of different samples from same spool @ 4. 2 K Large spread of Ic within same spool (SP 20100108 -1) for YBCO tape 1600 CERN 1500 LASA 1400 1300 Ic (A) 1200 +10% 1100 1000 900 800 700 600 0 2 4 6 8 B (T) 10 12 14

Conclusions • Critical current Ic measurements of Nb-Ti strand YBCO tape performed at 3 different laboratories are in good agreements. 11/23/2010 8