Conductor working group video-meeting P. Ferracin, S. Izquierdo Bermudez December 19, 2013

Nb-Ti leads parameters (from Luc) Strand: mm LHC strand, 1.6 Cu/SC ratio Cable: 34 strands, width of mm and a mid-thickness of 1.92 mm. Field (see slides 4-5) – In the nominal conditions (17.5 kA) we expect a field in the splice area of ~1.5 T – In the short sample condition (21.2 kA) we can say that the field in the splice area the field is ~2 T Critical current – Luc estimated approximately what would be the critical current of the cable 17 kA at 10 T and 1.9 K as high as 60 kA at 2 T and 1.9 K (to be confirmed) 44 kA at 2 T and 4.2 K 39 kA at 3 T and 4.2 K 19/12/2013 P. Ferracin2

Nb-Ti leads quantity and schedule Quantity for “magnet leads” – Assuming 8 m per coil we need (LARP+CERN) SQXF: 8m* 32 coils = 256 m LQXF: 8m * 33 coil = 264 m Series: 8 m * 135 coil = 1080 m Total: 1600 m Quantity for bus bars (see slide 6) – Total: 1500 m Total: ~3 km Schedule – Coil winding is expected to start in February 2014 – Additional samples could be needed to perform some bending tests for the design of the connection box Real estate is tight: we need to know the minimum hard-way bending radius 19/12/2013 P. Ferracin3 Double leads is presently LARP baseline; Is it possible to increase this number by 50 or 100%?

Susana Izquierdo Bermudez Field in Nb3Sn-Ti splice region 4 Magnetic Yoke & Pad =975 mm Non magnetic Pad =350 mm Non magnetic Pad = 225 mm

Susana Izquierdo Bermudez Field at the ends decay very quickly The fringe field of the magnet is negligible compared with the self-field of the interconnection 5 Field in Nb3Sn-Ti splice region Problems can be decoupled  Field in the interconnection can be computed analytically and/or with a very simple model I (kA)B p (T) (ANSYS*) B p (T) (ROXIE**) “Recycling” a very simple model I did for the LHC main interconnections * Does not consider iron and the rest of the leads ** Does not account for current flow in between cables Design Parameter for Nb-Ti lead: B p = 2T Current distribution

Bus bars for low-  quadrupoles Schematic view to be checked Q1+Q3 in series, Q2a+Q2b in series 10*2m + 20*4m + 10 *4m + 20*4m – Total 1 triplet = 220 m – Total 6 triplets = 1.5 km 19/12/2013 P. Ferracin6

Appendix 19/12/2013 P. Ferracin7

19/12/2013 P. Ferracin8