CERN/CEA Collaboration agreement No. KE2275/TE WP4 – Nb 3 Sn technology development Pré-Kick-off meeting 03/07/2014

Nb 3 Sn Technology development WP4 concerns the studies necessary on Nb 3 Sn cable prior to new coil winding. It is centered on FRESCA 2 cable but other cases as QXF or 11T cables could be analyzed. FRESCA 2 Cable characterization Mechanical tests facility at Saclay Cable behavior during heat treatment 03/07/2014 CA No. KE2275/TE - WP4 - Nb3Sn technology development 2

Cable expansion studies Insulated cable procured by CERN Ten stacks preparation and heat treatment at Saclay Dimensional measurements under 5MPa at CERN FRESCA 2 cable characterization 03/07/2014 CA No. KE2275/TE - WP4 - Nb3Sn technology development 3

Impregnated cable mechanical behavior studies Insulated cable procured by CERN Ten stacks heat treatment and impregnation at Saclay Compressions tests at RT Compressions tests at 4K Thermal contraction measurement between RT and 77K/4K at Saclay FRESCA 2 cable characterization 03/07/2014 CA No. KE2275/TE - WP4 - Nb3Sn technology development mm Impregnation insert and mold

Mechanical tests facility at Saclay Mechanical tests facilities at Saclay 03/07/2014 CA No. KE2275/TE - WP4 - Nb3Sn technology development 5 Compression tests set-up Thermal contraction set-up

Cable behavior during HT Short coil dilatation tool Mandrel total length: 690 mm Straight section total length: 600 mm Mandrel width: 90 mm 1.5 turns = 2.4 m of cable Mandrel configurations Configuration 0 – C0 Configuration 1 – C1 Configuration 2 – C2 Configuration 1 sym – C1 LE 03/07/ CA No. KE2275/TE - WP4 - Nb3Sn technology development 6

Cable behavior during HT 7 CA No. KE2275/TE - WP4 - Nb3Sn technology development 03/07/2014 CLOSED MANDREL MANDREL WITH CENTRAL GAP Stress witness

Cable behavior during HT PIT Cable 8 CA No. KE2275/TE - WP4 - Nb3Sn technology development 03/07/2014 Cable Mandrel material C1 Gap reduction % LSS C2 (*C1 LE) Gap reduction % LSS 1 central gap2 head gaps *1 PIT 1.82 mm Iron HT15.83 mm0.97%HT25.22 mm0.87% Stainless steelHT26.73 mm1.12%HT38.02 mm1.34% TitaniumHT25.50 mm0.92%HT37.94 mm1.32% PIT 1.86 mm IronHT7 (3 turns)5.16 mm0.86%HT47.69 mm1.28% Titanium HT74.96 mm0.83%HT48.82 mm1.47% HT95.84 mm0.97%*HT8*7.86 mm1.31% HT9 Step 190°C2.88 mm 49% of the final gap HT9 Step 400°C4.64 mm 79% of the final gap

Cable behavior during HT RRP Cable 9 CA No. KE2275/TE - WP4 - Nb3Sn technology development 03/07/2014 Mandrel material C1 Gap reduction L SS = 600 mm L TOT = 690 mm L cable = mm 1 central gap% L SS % L TOT (head to head) % L cable Titanium HT5 Central gap4.73 mm0.79%0.69%0.64% Total gap (central - lateral) 3.93 mm0.66%0.57%0.53% HT6 Central gap4.55 mm0.76%0.66%0.61% Total gap (central - lateral) 3.84 mm0.64%0.56%0.52% HT10 Central gap4.89 mm0.82%0.71%0.66% Total gap (central - lateral) 3.97 mm0.66%0.58%0.54%

Cable behavior during HT – next steps Complete RRP and PIT FRESCA2 cable tests campaign with reduced scale dilatation tool studying the influence of : SS length Number or turns Cable insulation Scale-1 Dilatation test 03/07/2014 CA No. KE2275/TE - WP4 - Nb3Sn technology development 10